Theorizing Institutional Entrepreneuring: Arborescent and rhizomatic assembling

A growing body of research has cataloged the myriad actors involved in tackling persistent institutional problems. Yet we lack a theoretical toolkit for explicitly conceptualizing and comparing diverse modes of institutional entrepreneuring—the processes whereby actors are created and equipped for institutional action—capable of ameliorating grand challenges. Drawing on assemblage theory, we articulate two ideal-typical modes of assembling actorhood: arborescent and rhizomatic. We differentiate each mode along four principles: association, combination, division, and population. Building on our theorization, we propound an arborescent-rhizomatic space comprising clusters of arborescent, rhizomatic, and hybrid actorhood. To explore the generativity of our framework, we revisit selected research at the intersection of institutional entrepreneurship and grand challenges. We close by articulating how our concept of assembling actorhood reorients research toward institutional entrepreneuring and contributes to the application of assemblage theory within organization studies.

principles constitutive of each mode: association, combination, division, and population. Whereas arborescent assembling relies on hierarchy and homogeneous multiplicities and is composed of dualisms, segmented according to taken-for-granted breaks, and propagated through genealogy and imitation, rhizomatic assembling entails centerless multiplicities comprising disparate connections between heterogeneous elements, which may break off and start up from any point, and populate through contagion and epidemics.
Building on these two ideal-type modes of assembling and their distinguishing principles, we reconsider previous research at the intersection of institutional entrepreneurship and grand challenges. Given their systemic and interdependent nature, grand challenges might evince actorhood that reflects either extreme of arborescent or rhizomatic modes of assembling, or some mixture of the two. Reading broadly but selectively, we problematize rather than merely summarize prior findings (e.g., Alvesson & Sandberg, 2020), with the ultimate goal of opening up new understandings of processes of institutional entrepreneuring.
We close by discussing how our concept of assembling reorients research in terms of institutional entrepreneuring specifically, and facilitates the application of assemblage theory within organization studies more generally. Notably, our assemblage theoretic model enables scholarship on institutional entrepreneurship to move past current dichotomies grounded in seemingly irreconcilable onto-epistemological assumptions (Garud et al., 2007;Hardy & Maguire, 2017) and reorients it towards institutional entrepreneuring. Whereas scholars have depicted these competing understandings as fundamentally different explanations, we posit that they are merely descriptions of different phenomena to be explained. Given its focus on modes of assembling actorhood, our approach provides an inherently processual foundation from which to theorize institutional entrepreneuring, without proscribing the configurations actorhood might take. Whether such assembling processes tend toward more arborescent or rhizomatic modes is an open question, one that can be both imagined and investigated using our conceptual framework.

Assemblage Theory and Actorhood
Over the past three decades, scholars have investigated myriad forms of institutional entrepreneurship (for recent reviews, see Hardy & Maguire, 2017;Micelotta et al., 2017). However, this work increasingly has been bifurcated into seemingly incommensurable perspectives, such as between actor-centric and process-centric accounts (Hardy & Maguire, 2008 and intentional versus emergent understandings of agency (Granqvist & Gustafsson, 2016). More recently, a new stream of research on grand challenges has emerged (Ferraro et al., 2015;George, Howard-Grenville, Joshi, & Tihanyi, 2016). As with research on institutional entrepreneurship, actors are a central focus. However, rather than balkanizing into one camp or another, grand challenges researchers appear to have elided these problems by taking a more ad hoc approach to theorizing actorhood (e.g., see the diversity of approaches in George et al., 2016). One downside is an impaired ability to integrate and generalize findings from this growing body of research. In both literatures, what has so far eluded scholars is a conceptual approach for theorizing institutional entrepreneuring that is flexible enough to accommodate different configurations of actorhood, expansive enough to address the complexities, uncertainties and evaluativities endemic to grand challenges, yet incisive enough to enable comparison and generalization across studies.
To address this onto-epistemological shortcoming (Alvesson & Sandberg, 2011), we turn to assemblage theory (Deleuze & Guattari, 1975, 1976, 1980, 1986, 1987 to theorize the assembling processes whereby actorhood is configured within particular historical contexts (Nail, 2017). Although assemblage theory is increasingly drawn upon in organization and management research, scholars have overlooked its potential contributions to the conceptualization of actorhood. For instance, some scholars have built on conceptualizations of assemblage offered by Callon or DeLanda, which diverge from Deleuze and Guattari's and ignore the rhizome-tree distinction that runs through A Thousand Plateaus (Buchanan, 2015). Hence, we opted to directly read Deleuze and Guattari, distilling from them two ideal-type modes of assembling actorhood: arborescent and rhizomatic.

Deleuze and Guattari's concept of assemblage
The concept of assemblage is the "general logic" running through A Thousand Plateaus (Nail, 2017). Unfortunately, the English word assemblage does not adequately capture the meaning of the original term agencement, which refers to the action of matching or fitting together a set of components (agencer). Thus, contrary to what is connoted by the English term, Deleuze and Guattari's original terminology denotes a "process of arranging, organizing, fitting together," not the static arrangement resulting from such a process (Wise, 2011, p. 91). In other words, assemblage theory might be more aptly called assembling theory, in which attention is squarely on the processes of "assembling agency" (Bowden, 2020).
Critical to Deleuze and Guattari's concept of assemblage is the notion of multiplicity. "The book's fundamental claim is that things in general are, at bottom, assembled multiplicities as opposed to substances. Indeed, the particular elements of assembled multiplicities are also more or less loosely assembled multiplicities, all the way down, as it were" (Bowden, 2020, p. 386). As one consequence, assemblages are not unities; instead, they comprise many distinct interconnected components, including both content (i.e., pragmatic components such as bodies, tools, actions, etc.) and expression (i.e., semiotic components such as signs, utterances, etc.). Because these components retain their autonomy, they can "take flight" from one assemblage and join another. For example, human, horse, and bow comprise the mounted archer assemblage (Deleuze & Guattari, 1987), but each of these components can be found in other assemblages. In a more complex example, the electric power grid assemblage includes not only human bodies, machines, wires, coal, fire, electrons, and electromagnetic fields, but computer programs, legislation, and human desires (Bennett, 2005). What defines an assemblage are the relationships between components that shape what it is and what it is capable of doing (Wise, 2011), and these are always a matter of processes of assembling. Given these dynamics, the possibility of change is present in any assemblage; no assemblage is permanent (Wise, 2011).
Each assemblage is unique, with its own history of formation (Nail, 2017). In Deleuze and Guattari's (1987) language, an assemblage's identity is defined by its territory, which it marks, claims, carves out or seizes from the strata-the physicochemical, organic, and alloplastic layers or milieus on which it sits. Put differently, every assemblage is composed of decoded fragments borrowed from its milieus. Thus, "the first concrete rule for assemblages is to discover what territoriality they envelop" (p. 503). Yet, every assemblage contains within it processes of change-"deterritorialization"-that destabilize and transform it. These open an assemblage up, allowing it to connect to other assemblages and expand its territory, but also expose it to loss, contraction, decay, and even death.
From an assemblage perspective, actorhood is far from an exclusively human endeavor. Instead, actorhood emerges from interactions between many interconnected components, which include non-human actors of all sorts, from the laws of physical matter and the biological processes of organisms to bureaucracies, theories, and machines. Thus, in a very real sense, for Deleuze and Guattari, there is no actorhood apart from an assemblage, and conversely there is no assemblage without actors that bring it about (Nail, 2017). They are defined by their capacities to affect and be affected, and the compositions they can or cannot make.
Finally, we see compatibilities between assemblage theory and institutional theory, particularly the latter's more phenomenological and constructivist variants (Jepperson, 1991;Meyer & Vaara, 2020). Deleuze and Guattari's ontology is one of immanence (Bowden, 2020;Nail, 2017) in which experience is seen not "as a relation between a subject who senses and an object that is sensed," but rather "as being prior to subjects and objects . . . a subjectless and objectless field of experience" (Lawlor, 2017, p. 62). This is a position that comports well with recent developments in institutional theory (Friedland, 2013;Mutch, 2018), and its early foundations (Gehman, 2021;Meyer, 2008).

Assemblage ontology: The foundation of arborescent and rhizomatic assembling
We have on numerous occasions encountered all kinds of differences between two types of multiplicities: metric and nonmetric; extensive and qualitative; centered and acentered; arborescent and rhizomatic; numerical and flat; dimensional and directional; of masses and of packs; of magnitude and of distance; of breaks and of frequency; striated and smooth. (Deleuze & Guattari, 1987, p. 484) In addition to developing the concept of assemblage, in A Thousand Plateaus, Deleuze and Guattari introduced two ideal types: the rhizome and the tree. In botany, a rhizome is a type of plant stem that grows horizontally underground and is composed of many nodes, each of which can sprout a shoot. The shoots grow out of the ground, becoming the visible part of the plant, while the rhizome itself is often hidden from human sight. Examples include ferns, spider plants, ginger, bamboo, and lotus flowers, as well many invasive plants. Building on this imagery, Deleuze and Guattari appropriated the term to designate a certain type of assemblage that functions as a centerless, ever-changing, and unpredictable network composed of interconnected, heterogeneous elements (Chia, 1999;Linstead & Thanem, 2007).
Throughout A Thousand Plateaus, Deleuze and Guattari contrasted the rhizome with a tree: "a rhizome as subterranean stem is absolutely different from roots and radicles" (Deleuze & Guattari, 1987, p. 6). Whereas the rhizome structure often remains invisible, the tree structure, or arborescence, is central to how we think and describe the world (Adkins, 2015). "The tree imposes the verb 'to be' but the fabric of the rhizome is the conjunction, 'and ... and ... and ...'" (Deleuze & Guattari, 1987, p. 25). Indeed, the distinction between these two ideal types is a recurring theme throughout A Thousand Plateaus.
Building on this fundamental distinction, in the remainder of this section, we differentiate between the tree and the rhizome and show how they constitute two ideal-typical modes of assembling actorhood: arborescent and rhizomatic. Through a close reading of Deleuze and Guattari's (1987, p. 7) attempt to "enumerate certain approximate characteristics of the rhizome," we identify four principles along which to analytically distinguish arborescent and rhizomatic assembling: association, combination, division, and population (see Table 1).
Principle of association. First, arborescent and rhizomatic assembling can be distinguished according to the principle of association. A tree embodies stable and hierarchal organization; it "plots a point, fixes an order" (Deleuze & Guattari, 1987, p. 7). Thus, arborescent assembling is built upon hierarchical structures that connect similar elements (Adkins, 2015). Logic, biology, and linguistics all rely on trees. Taxonomic systems are arborescent. For example, in biology, all organisms are organized into a "tree of life" according to their species. More complex species branch out from simpler ones, their common ancestors. Likewise, in linguistics, languages branch out from common ancestors through processes of mutation. More generally, arborescent assembling reduces complexities through codification and grammatical operations.
The stability and order of arborescent assembling is achieved through a homogenizing process that elevates one particularity while subordinating other differences. In biology, for instance, a large number of species can be categorized under the root concept "mammal" or "vertebrate" despite significant differences between them. More generally, arborescent assembling "simplif[ies], or at the very least tame[s] hugely complex or proliferating systems" (Glezos, 2012, p. 164). Importantly, in arborescent assembling, hierarchy pre-exists the individual, and transmission proceeds through preestablished channels: "An element only receives information from a higher unit, and only receives a subjective affection along preestablished paths" (Deleuze & Guattari, 1987, p. 16). For instance, in biology, genetic code is passed down from ancestor to descendant. By comparison, "the rhizome connects any point to any other point, and its traits are not necessarily linked to traits of the same nature" (Deleuze & Guattari, 1987, p. 21). For instance, while fabric is arborescent, composed of warp and woof, felt is rhizomatic, comprising multiple and random connections between fibers. Moreover, rhizomatic assembling creates relations between heterogeneous elements with no fixed structure and no single center. The Internet is an example of rhizomatic assembling. More generally, Glezos (2012) proposed that rhizomes subvert traditional hierarchies. Transversal lines cut across the normal order from local to national to international; top-down initiatives co-exist alongside allegiances between disparate groups. Compared with arborescent assembling, rhizomatic assembling is not a reduction to linguistic universals, but instead involves a throng of dialects.
Finally, the internal organization of rhizomatic assembling is in constant flux because it ceaselessly establishes new connections between elements. Beyond connecting heterogeneous entities, rhizomatic assembling enables novel transmissions and translations of information. Viruses follow this rhizomatic pattern. Deleuze and Guattari (1987, p. 10) noted that some viruses "can take flight, move into the cells of an entirely different species," thereby transporting genetic material, influencing evolution, and creating transversal genetic links between species not otherwise connected; thus, "our viruses cause us to form a rhizome with other animals." Viewed in light of the Covid-19 pandemic, their comment first published in 1980 is eerily prescient: The difference is that contagion, epidemic, involves terms that are entirely heterogeneous: for example, a human being, an animal, and a bacterium, a virus, a molecule, a microorganism... These combinations are neither genetic nor structural; they are interkingdoms, unnatural participations. (Deleuze & Guattari, 1987, pp. 241-242) Principle of combination. Second, arborescent and rhizomatic assembling produce multiplicities that combine many elements, but these multiplicities are inherently different. Arborescent assembling creates multiplicities that subsume the many under the one through "coding" moves such as labeling, framing, and categorizing (Adkins, 2015). Categories and labels homogenize and simplify, but also dichotomize, creating distinctions which must in turn be dialectically brought together or unified according to some higher principle (Holland, 2013). "The notion of unity appears only when there is a power takeover in the multiplicity by the signifier or a corresponding subjectification proceeding" (Deleuze & Guattari, 1987, p. 8). "Coding" is essential to arborescent assembling in the sense that it depends on the ascription of identities to create multiplicities that will "hold their shape." Consequently, the assemblages that arborescent assembling produces are often "overcoded": their components have fixed and specific meanings or statuses, and are subject to rigid rules (Deleuze & Guattari, 1987).
By comparison, rhizomatic assembling builds "true" multiplicities having "neither subject nor object, only determinations, magnitudes, and dimensions that cannot increase in number without the multiplicity changing in nature" (Deleuze & Guattari, 1987, p. 8). Differences are allowed to persist and co-exist; they might be dynamically negotiated, but they are never erased. In this way, rhizomatic assembling yields "not a discrete, static unity, but something constantly entering into and breaking off combinations with other multiplicities" (Adkins, 2015, p. 26).
The assemblages resulting from rhizomatic assembling amount to nothing more than their elements and the connections between them. No "supplementary dimensions" hold them together. For instance, Glezos (2012, p. 174) described transnational activism as rhizomatic; it is "not just a process of different agents coming together in recognition of an implicit unity which precedes them . . . or a coded negotiation between pre-existing local unities with established and essential identities and interests." Rather, it is a process of becoming: "Transnational activism does not just build new movements, it also builds new actors" (Glezos, 2012, p. 174), and such ongoing interactions change identities and evoke new perceptions.
Principle of division. Third, arborescent and rhizomatic assembling can be distinguished according to the principle of division. Arborescent assembling strives for neat divisions along "natural" boundaries and separations between their constituent parts or segments, which are ordered in nesting hierarchies of importance. In this way, arborescent assembling works with "discrete and atomistic units" which "are in principle separable" (Adkins, 2015, p. 27). Deleuze and Guattari (1987, pp. 9, 198) referred to these as "oversignifying breaks," in which power is a function of taken-forgranted roles, scripts, and categorizations. When unexpected disruptions occur (i.e., breaks appear at "unnatural" locations), arborescent assembling requires that these disruptions be resolved at a higher level in the hierarchy for the assembling process to recover and continue.
Mimicry and imitation are strategies commonly employed in arborescent assembling to bridge seemingly irreconcilable differences between assemblages. Deleuze and Guattari used the unusual relationship between a particular type of orchid and a wasp as an example. Certain orchids can emit the same pheromones as females of a particular wasp species in addition to having external parts that resemble those females in appearance. Consequently, males of the wasp species attempt to mate with those parts, thereby pollinating the orchid. One interpretation is that this relationship constitutes arborescent assembling: "it could be said that the orchid imitates the wasp, reproducing its image in a signifying fashion" (Deleuze & Guattari, 1987, p. 10). However, Deleuze and Guattari (1987, p. 10) rejected this interpretation, averring instead that "something else entirely is going on: not imitation at all but a capture of code." Rhizomatic assembling, on the other hand, operates with neither natural separations nor clear boundaries; it refuses to carve nature at its joints (Adkins, 2015). Instead, rhizomatic assembling segments by "asignifying ruptures." Thus, a rhizome "may be broken, shattered at a given spot, but it will start up again on one of its old lines, or on new lines" (Deleuze & Guattari, 1987, p. 9). Whereas arborescent assembling tends toward territorialization (i.e., processes producing defined identities, routinized behaviors, and fixed boundaries), rhizomatic assembling tends toward deterritorialization (i.e., processes that result in more ambiguous identities, non-routinized behavior, and porous boundaries).
Deterritorialization can be seen as threatening, because it is destabilizing, but it is also generative, since it offers an escape from rigid repetition, as exemplified by improvisation in jazz (Holland, 2013). Such "lines of flight"-Deleuze and Guattari's term for escapes from fixed routines-open new possibilities, allowing rhizomatic assembling to expand, create new connections, and develop new repertoires, thereby fostering innovation and resilience. According to Taguchi (2016, p. 45): "This means actively engaging in a practice of estrangement to get away from takenfor-granted and common sense significations." Thus, Deleuze and Guattari concluded that the relationship between orchid and wasp is actually an example of rhizomatic assembling. Each is deterritorialized by the interaction as it becomes part of the other. And yet, the orchid is also reterritorialized; its reproduction is ensured.
Principle of population. Fourth, arborescent and rhizomatic assembling differ with regard to the principle of population. Arborescent assembling is founded on a genetic axis and grows and expands by following a plan or blueprint-that is, by applying or reproducing something readymade. Describing this phenomenon, Deleuze and Guattari used the term "decalcomania," as in the act of applying a decal or sticker (Adkins, 2015). Arborescent assembling populates by means of transferring existing pictures to other surfaces, or by making a tracing, reflecting a fundamentally self-referential or representationalist approach (Watson, 2013).
To illustrate, Deleuze and Guattari (1987) referred to the work of psychoanalysts such as Klein and Freud, who took the rich psychological experiences of their patients and reduced them to familiar categories or "molar unities:" "the father, the penis, the vagina, Castration with a capital C..." (p. 27, emphasis in the original). Here, as with arborescent assembling more generally, the psychoanalyst relies on alleged "competence." Deleuze and Guattari critiqued this "decalcomania" as limiting: "Klein and Freud only have three stickers, . . . mother, father, and child. Whatever map the patients draw the analysts insist that these stickers be placed over the top so the pictures always come out the same, as Oedipus" (Adkins, 2015, pp. 29-30). In other words, tracings always follow pregiven structures and predefined pathways (Bowden, 2020).
Rhizomatic assembling, on the other hand, "make[s] a map, not a tracing" (Deleuze & Guattari, 1987, p. 12). "A map is always contingent and partial, always drawn for some purpose, and omitting that which is, at that point, considered irrelevant" (Glezos, 2012, p. 177). Mapping is a performance, a singularity, and yet, alternative mappings of the same territory are possible, any of which may prove useful. There is no single entry or exit to the map, no one structure or generative order: "one of the most important characteristics of the rhizome is that it always has multiple entryways" (Deleuze & Guattari, 1987, p. 12). Whereas tracings are sedentary, maps are nomadic. In place of heredity or mimesis, rhizomes propagate by epidemic and contagion. Such rhizomatic population depends on experimentation (Watson, 2013); the ever-changing outcome is emergent, and cannot be known a priori (Bowden, 2020). This also means that a rhizome "has no beginning or end; it is always in the middle, between things, interbeing, intermezzo" (Deleuze & Guattari, 1987, p. 25). A rhizome is always becoming.

Assembling actorhood: Between the tree and the rhizome
No sooner do we note a simple opposition between the two kinds of space than we must indicate a much more complex difference by virtue of which the successive terms of the oppositions fail to coincide entirely. And no sooner have we done that than we must remind ourselves that the two spaces in fact exist only in mixture: smooth space is constantly being translated, transversed into a striated space; striated space is constantly being reversed, returned to a smooth space. (Deleuze & Guattari, 1987, p. 474) Although Deleuze and Guattari (1987, p. 13) acknowledged that they had "reverted to a simple dualism" by theorizing binary oppositions, they also went out of their way to periodically break them down, subvert them, or dance away from them. As is evident above, dualisms are associated with arborescence: "binary logic is the spiritual reality of the root-tree." Yet, they were clearly dissatisfied with arborescence: "We're tired of trees. We should stop believing in trees, roots, and radicles. They've made us suffer too much" (Deleuze & Guattari, 1987, p. 15).
Whereas contrasting ideal types is clearly useful for theorizing, doing so also poses the danger of oversimplification. Deleuze and Guattari (1987) identified three problems of dualism. First, differences are too complex to neatly fit into a binary opposition, and therefore their theoretical ideal types are not in fact mutually exclusive opposites. Second, when looking for ideal types in real phenomena, one often finds mixtures, or "rhizome-root assemblages" (p. 15). Finally, phenomena more closely associated with one ideal type can transition (or be translated) to more closely resemble another: "There exist tree or root structures in rhizomes; conversely, a tree branch or root division may begin to burgeon into a rhizome" (p. 15).
We agree with Deleuze and Guattari on these points. Although we have theorized two opposing ideal-type modes of assembling, these modes need not result in the assembly of pure types of actorhood; they also can produce a variety of combinations, or hybrids. Furthermore, actorhood is dynamic and can transition from being more rhizome-like to being more tree-like. Critically, an assemblage ontology provides a means of theorizing two modes of assembling actorhood.

Actorhood in the Arborescent-Rhizomatic Space
In this section, we explore the potential utility of our conceptual framework by examining the extent to which prior research at the intersection of institutional entrepreneurship and grand challenges manifests these four principles. Our primary goal in doing so is to explore the relevance of rhizomatic and arborescent assembling to scholarly understandings of institutional entrepreneuring. In particular, we theorize an arborescent-rhizomatic space wherein actorhood may be assembled in arborescent, rhizomatic, or hybrid configurations (see Figure 1). We then apply the ideal-type principles to selected articles at the intersection of institutional entrepreneurship and grand challenges. We categorize studies manifesting at least three rhizomatic principles as illustrating rhizomatic actorhood. Similarly, we categorize studies manifesting at least three arborescent principles as illustrations of arborescent actorhood. Studies that manifest a mix of principles are categorized as hybrid actorhood. Our evaluation of prior work brings into sharp relief the capacity for an assemblage ontology to explain different types of actorhood (e.g., centralized versus distributed). In doing so, we expand the interpretive space for understanding institutional entrepreneuring by showing that it is not restricted to either rhizomatic or arborescent assembling, but may manifest in different admixtures of the two. This expanded interpretive space affords researchers a toolkit for grappling with institutional entrepreneuring in a flexible and unified way.

Arborescent actorhood
In a number of prior studies, scholars have theorized institutional entrepreneuring in terms of arborescent assembling. For example, Battilana and Dorado's (2010) study of two Bolivian microfinance organizations-BancoSol and Los Andes-clearly evidences all four arborescent principles. Through their activities, these two organizations were exposed to a community and a financial logic, each with distinct goals, management principles, and target populations. Members experienced a tension between the two logics, which they felt compelled to resolve, illustrating arborescent dualism. Instead of connecting and sustaining differences, interactions within the assembling processes were aimed at synthesizing the two logics into a higher-order microfinance logic by selecting, balancing, or combining elements from each. Central to this approach was the creation of a common organizational identity based on operational excellence which discouraged the formation of subgroup identities aligned with either the community or the finance logic.
Furthermore, oversignifying breaks, another feature of arborescent assembling, were evident in the way the two logics were embedded in the education and professional experiences of employees, producing the threat of fracturing. Battilana and Dorado (2010) argued that these logics are always on the verge of breaking each other down when combined, because employees who exclusively align with either logic struggle to overcome their oversignified understandings. The solution devised by one organization was to transcend both logics at the higher level of human resource practices and staffing policies by hiring employees with little experience, who are therefore not deeply embedded in either logic (what they call tabula rasa), and "stamping" the organization's identity on them through socialization practices. This reflects the arborescent principle of decalcomania (or tracing).
More generally, among the studies we reviewed that evidenced arborescent assembling, oversignifying breaks were particularly prominent. Whether it was sustainable forestry (Zietsma & Lawrence, 2010) or business response to climate change (Wright & Nyberg, 2017), the idea of "breaks" from the status quo appeared feasible only when signified in terms of familiar categories. Interestingly, in prior studies manifesting one rhizomatic and three arborescent principles, the rhizomatic principle of connection and heterogeneity was evident. This is likely because addressing grand challenges, by its very nature, requires combining heterogeneous elements, such that even within arborescent assembling, heterogeneous connections become necessary. Mair and Hehenberger's (2014) study of the emergence of venture philanthropy as a new institutional model within the established field of traditional philanthropy provides a vivid illustration of all four principles of rhizomatic assembling. Whereas traditional philanthropy involves making gifts or grants to organizations that address social problems, venture philanthropy emphasizes holding recipient organizations accountable by establishing specific terms of reciprocity between the giving and receiving entities. Mair and Hehenberger's (2014) core thesis is that the emergence of venture philanthropy can be explained by assembling that connects a variety of people and organizations with disparate traits through "frontstage" and "backstage" events, which accords with the rhizomatic principle of connection. In their case, frontstage events such as conferences brought together organizations such as "foundations, private equity firms, private banks, and universities" that "cut across silos" of traditional and venture philanthropy (p. 1186). In contrast with arborescent hierarchy, these organizations had equal status as members of the European Venture Philanthropy Association (EVPA), a "broad church" that encompassed many entities. In turn, this diversity facilitated widespread adoption of venture philanthropy models.

Rhizomatic actorhood
Furthermore, Mair and Hehenberger's (2014) study illustrates rhizomatic multiplicity by showing that contradictory institutional models of venture and traditional philanthropy can co-exist in a state other than competition or a fragile truce (e.g., Battilana & Dorado, 2010;Marquis & Lounsbury, 2007). They demonstrated how institutional entrepreneurs created safe "backstage" spaces for deconstructing the venture philanthropy model, allowing the discussion to move from ideology (why) to practices (how). Participants debated the adoption of venture philanthropy practices by sharing their experiences, "driving the transition toward mutualistic relationship" (Mair & Hehenberger, 2014, p. 1188. Mair and Hehenberger's (2014) study also captures rhizomatic assembling via asignifying rupture. As venture philanthropy began to gain traction in Europe, breakdowns occurred between the two institutional models. Amid conflict and confrontation, the EVPA was established in 2004 to organize annual conferences in open spaces accessible to all. Participants soon realized that venture philanthropy practices needed refinement. Akin to a rhizome starting on new lines after a rupture, these workshops helped resolve conflicts over contested practices, bolstering the establishment of the venture philanthropy model. Each new shoot (i.e., venture philanthropy practice), while challenging the traditional philanthropy model, injected new energy into the process and contributed to the institutionalization of the venture philanthropy model.
Finally, Mair and Hehenberger's (2014) study illuminates rhizomatic cartography by showing how events can become relational spaces that lack a generative order and are instead emergent in response to ongoing challenges in the field. For example, once the frontstage space of conferences no longer enabled actors to understand and adopt specific venture philanthropy practices, smaller "backstage" workshops emerged.
More generally, across studies, rhizomatic assembling was not a feature of a single actor or a monolithic group of actors; rather, it emerged from the assembling of individuals, organizations, events, and ideologies from divergent fields that came together to address grand challenges. These entities retained their autonomy and distinctiveness in the process of rhizomatic assembling. Furthermore, grand challenges contexts such as market-building, governing institutions such as professional associations, and fields such as venture philanthropy may lend themselves to asignifying rupture such that conflicts do not endure along taken-for-granted boundaries. In such circumstances, actorhood need not dualistically pit one logic against another or old against new. Even when studies depict arborescent dualism, such as between local and national logics (Marquis & Lounsbury, 2007) or between stakeholders and an organization (Ferraro & Beunza, 2018), they evoke rhizomatic features with regard to the other three principles. Connection in rhizomatic assembling through, for example, dialogue (Ferraro & Beunza, 2018) or envisioning a common fate (Ansari, Wijen, & Gray, 2013), can be employed to address such dualisms. Other studies instead highlight arborescent decalcomania, such as when neoliberal principles undergird initiatives such as forest certifications (Bartley, 2007), or when responsibility frames are invoked to address the problem of conflict minerals (Reinecke & Ansari, 2016).

Hybrid actorhood
To illustrate the qualities of hybrid actorhood, we turn to Etzion and Ferraro's (2010) study of the Global Reporting Initiative (GRI) from the mid-1990s to 2010. Actorhood in this study embodies two arborescent principles (dualism and decalcomania) and two rhizomatic ones (connection and asignifying rupture). The rhizomatic principle of connection is evident in the GRI's early history. Assembling took place as the GRI pushed to establish sustainability reporting standards in concert with other organizations such as NGOs, chambers of commerce, investors, labor organizations, research institutes, etc., thereby "embodying the emergent field that it was attempting to steer" (p. 1096). The GRI achieved its goal of engaging in participative decision making to facilitate agreement among this diverse set of stakeholders. This agreement was important for GRI reporting to be accepted by actors in the field.
The formation of the GRI also reflects the rhizomatic principle of asignifying rupture. The Coalition for Environmentally Responsible Economies (now, Ceres), a multisector NGO, played a central role in institutionalizing non-financial reporting. Ceres initially advocated for social and environmental reporting in the late 1990s, noting the reporting disparities across organizations. Seeing this heterogeneity as an opportunity, Ceres launched the GRI as a standard for reporting on nonfinancial metrics, thereby transferring its mandate to the GRI as an offshoot and creating a new line.
Conversely, arborescent dualism is reflected in how actors involved in assembling processes conceived of the relationship between financial reporting and GRI reporting. Etzion and Ferraro (2010) described the institutionalization of GRI reporting as relying on analogy. For GRI reporting to take hold, it had to be made analogous to financial reporting, and later distinguished as a separate concept. Two separate, dualistic entities-financial and non-financial-had to be framed as analogous to each other.
Finally, Etzion and Ferraro's (2010) study illuminates arborescent decalcomania, in the evolution of the materiality, transparency, and completeness of reporting guidelines from 1999 to 2006. A clear structure that could be traced and re-traced across organizations was important in establishing GRI reporting. For example, the authors described how BP created a materiality matrix to ensure that reported data had material meaning for stakeholders. BP's materiality matrix identified materiality based on the "level of external concern" and "potential impact on BP's ability to deliver strategy" (p. 1103). The structure and order afforded by clear guidelines was important for institutionalizing GRI reporting.
A different kind of hybridity is evident in Dentoni, Pascucci, and Gartner's (2018) comparison of identity-persisting and identity-shifting community-based enterprises (CBEs). Hybrid assembling in this case included the CBEs, their stakeholders, and the routines developed to engage in distributed experimentation and make sense of emerging epiphanies. One set of CBEs, which largely reflected arborescent principles, engaged solely with positive epiphanies or exhibited only limited engagement with negative epiphanies, leading to identity persistence as they reorganized around old identities. Another set of CBEs, which largely adhered to rhizomatic principles, engaged with both positive and negative epiphanies, thereby facilitating identity shifts that led them to reorganize their practices around new identities. Importantly, hybridity in the actorhood of all CBEs stemmed from actions aimed at distributed experimentation which fostered two identity pathways: one that transformed identities and one that sustained them. In other words, both types of CBEs exhibited hybrid actorhood.
Hybrid actorhood is also manifested when assembling processes exhibit both sides of the same principle. For instance, Dorado (2013) showed that the entry of many organizations with different preferences for hierarchy and connection into the microfinance field made institutional entrepreneurship at the field level possible. Whereas BancoSol was launched by a cross-section of tightknit elites from the community and the finance and banking industries, Los Andes was established by individuals from diverse backgrounds who drew on personal social networks to support the new venture. At the field level, microfinance assembling emerged through a combination of rhizomatic (i.e., connection) and arborescent (i.e., hierarchy) principles.

Discussion
Understanding actorhood has been a perennial concern of organization and management scholars (Hwang & Colyvas, 2020;Meyer, 2010). The need to better theorize types of actorhood is especially evident in prior literature on institutional entrepreneurship (Battilana et al., 2009;Hardy & Maguire, 2008, and more recently, in the burgeoning literature on grand challenges (Ferraro et al., 2015;George et al., 2016). To address this need, we have built on Deleuze and Guattari's (1987) landmark work to articulate two ideal-typical modes of assembling actorhood: arborescent and rhizomatic. Applying this framework to research at the intersection of institutional entrepreneurship and grand challenges enabled us to explore both the applicability and the generativity of our conceptual approach. Specifically, we have identified an arborescent-rhizomatic space by decomposing the actorhood evident in prior work according to the four principles in our framework. Below, we discuss how our work contributes to the revitalization of research on institutional entrepreneuring. We close by examining how our work contributes to the application of assemblage theory within organization studies.

Revitalizing institutional entrepreneuring
Our first contribution relates to longstanding interest in institutional entrepreneurship (Garud et al., 2007;Hardy & Maguire, 2017;Pacheco et al., 2010), and more recent suggestions to reorient this research in the direction of institutional entrepreneuring (Hjorth & Reay, 2018). Some 25 years ago, Holm (1995, p. 398) asked: "How can actors change institutions if their actions, intentions, and rationality are all conditioned by the very institution they wish to change?" Such provocations, together with DiMaggio's (1988, p. 14) concept of the institutional entrepreneur, sparked a string of widely cited studies (e.g., Garud, Jain, & Kumaraswamy, 2002;Maguire, Hardy, & Lawrence, 2004), as well as a highly influential special issue (Garud et al., 2007).
However, the once vibrant work in this area seems to have plateaued. For instance, few notable studies were published between Hardy and Maguire's reviews in 2008 and 2017. Recent studies have arguably revealed more incremental insights by examining previously overlooked settings or particular stages of institutional change processes (Canales, 2016;Qureshi, Kistruck, & Bhatt, 2016). In our view, this outcome is at least partly due to the growing reification of apparently incommensurable dualisms (Hardy & Maguire, 2008;Granqvist & Gustafsson, 2016;Pacheco et al., 2010). Work on institutional entrepreneurship thus has ossified into different ontological camps, and in the process, become somewhat stifled.
In an effort to revitalize this important scholarly conversation, we have proposed an approach to theorizing actorhood that emphasizes the processes whereby actors are created and equipped for institutional action. Building on a set of principles derived from Deleuze and Guattari's work, we have identified how arborescent and rhizomatic modes of assembling make possible diverse configurations of actorhood. In a "differentiating move that clears a new direction" (Steyaert & Hjorth, 2003, p. 7), we have endeavored to open an arborescent-rhizomatic space that enables new understandings of the notion of institutional entrepreneuring (Hermes & Mainela, 2015;Hjorth & Reay, 2018).
In formulating the distinction between arborescent and rhizomatic modes of assembling, our point is not to simply replace prior dualisms with a new one. Rather, our aim has been to "employ a dualism of models only in order to arrive at a process that challenges all models . . . We arrive at the magic formula we seek-pluralism = monism" (Deleuze & Guattari, 1987, p. 20). In this regard, our assemblage theoretic model of actorhood problematizes the onto-epistemological assumptions (Alvesson & Sandberg, 2011) sustaining prior dualisms. Whereas scholars have depicted these competing understandings as ontological differences, we posit them as merely phenomenal descriptions on which researchers have based their analyses. Rather than pre-committing analysts to a single type of actorhood, our assemblage perspective leaves open the question of an actor's ontology. Consequently, seemingly fundamental distinctions (e.g., actor-process, rationalnonrational) are reformulated as merely phenomenal and lose their edge. This is a "mode of individuation very different from that of a person, subject, thing, or substance. . . . Climate, wind, season, hour are not of another nature than the things, animals, or people that populate them, sleep and awaken within them" (Deleuze & Guattari, 1987, pp. 261, 263). Concomitantly, a single ontology provides a foundation from which to explain diverse types or configurations of actorhood. Key here is an understanding of what an assemblage can do, its active and passive effects, and the compositions it can or cannot make.
By revisiting prior work through the lens of assemblage theory, we have provided an expanded interpretive space for institutional scholars to fully embrace the processes of institutional entrepreneuring. Doing so is different from process-centric accounts, which are posited as the opposite of actor-centric accounts (Hardy & Maguire, 2017). Assemblage theory understands actorhood as at once immanent and the result of ongoing assembling processes. It thus allows investigation of both processes and the configurations that define actorhood's essential features. Extending this insight, it becomes clear that institutional entrepreneuring itself depends on actorhood; actorhood is not only an outcome of assembling processes, but also its milieu or medium. For example, viewing institutional entrepreneuring "as an emergent outcome of activities of diverse, spatially dispersed actors" (Hardy & Maguire, 2017, p. 274), might be explained in arborescent terms as a matter of hierarchy and homogeneity, or in rhizomatic terms as entailing lines of flight between heterogeneous elements. At the same time, focusing on configurations of actorhood, their capacity for reflexivity or their cognitive and emotional compositions could be explained by arborescent principles such as oversignification. Conversely, rhizomatic principles of heterogeneity and connection are evident in accounts of institutional entrepreneuring that emphasize building connections to alternate institutions within the milieus they inhabit.
Reformulating the ontological into the phenomenal has important implications for institutional theory broadly, and institutional entrepreneuring more specifically. For instance, consider the socalled paradox of embedded agency that has animated considerable scholarly debate (Garud et al., 2007;Holm, 1995). Some scholars have insisted that any study of institutional change "must give full explanatory weight to agency and conceive the full gamut of human action" (Delbridge & Edwards, 2013, p. 928). According to this view, institutional entrepreneurs are defined by interests, goals, reflexivity, and coercive capacity (Mutch, 2007). This perspective contrasts starkly with those who hold that "social realities are hierarchically structured and at least partly independent of individual actors at any given time" (Modell, Vinnari, & Lukka, 2017, p. 64).
Assemblage theory informs this debate in two ways. First, it allows researchers to theorize actorhood in ways that are unique to each phenomenon and research problem (e.g., Hwang & Colyvas, 2020). Embeddedness can be seen as a feature of actorhood resulting from its mode of assembling. For example, more arborescent institutional entrepreneuring, characterized by imitation, oversignification, and hierarchy, could produce highly embedded actors. On the other hand, less embedded actorhood may be the result of rhizomatic assembling, marked by contagion, lines of flight, and heterogeneity. In this regard, our assemblage theoretic typology can help researchers "lengthen, prolong, and relay the line of flight" (Deleuze & Guattari, 1987, p. 11), thereby moving to new territories in theorizing beyond the paradox of embedded agency.
Second, assemblage theory's highly relational and material underpinnings decenter the interests, goals, and reflexivity of human actors. Such a corrective harkens back to Friedland and Alford's (1991, p. 240) original admonition to bring society back in: "One cannot derive a theory of society from the historic individuality that those institutional transformations created. The transhistorical individual cannot have ontological priority." Instead, it is necessary to specify "the institutional bases of individual and organizational identities, interests and actions." An assemblage perspective enables such theorization, one capable of encompassing not only human actors and the institutions they inhabit, but also myriad other elements. It is through the totality of these interactions and interrelations that actorhood emerges.

Assemblage theory in organization studies
Our research contributes to the growing interest in assemblage theory within organization studies (Carton, 2020;D'Adderio & Pollock, 2014;Glaser, 2017;Glaser et al., 2021;Orlikowski & Scott, 2008). Despite increasing awareness and selected use of the assemblage concept, few scholars have engaged with what is arguably Deleuze and Guattari's more profound contribution: the distinction between arborescent and rhizomatic assembling. For instance, although the term rhizome has been mentioned a handful of times in Organization Studies, it has always been in passing (e.g., Linstead & Thanem, 2007;Parker, 2017;Välikangas & Carlsen, 2020).
Looking more broadly, the few scholars who have engaged with these concepts typically have done so metaphorically. For instance, Chia (1999, p. 210) proposed a "rhizomic" model of organizational change, contrasting it "against the dominant evolutionary, contextualist, and punctuated equilibrium models of change." Steyaert (2007) proposed taking a radical processual approach to studying entrepreneurship, and suggested doing so based on a Deleuze-inspired "rhizomatic logic." Kornberger, Rhodes, and ten Bos (2006, p. 66) contrasted arborescent and rhizomatic approaches to organizing, describing the arborescent approach as "one where 'all roads lead back to Rome' and where Rome is inevitably the 'top' of the organization." Offering the most sustained engagement we could find among organization scholars, Wood and Ferlie (2003) described "the organization of health care knowledge as non-linear, rhizomic communication" (p. 47) as opposed to "more widely assumed mechanisms of linear connectionism" (p. 58). Finally, stepping a bit further afield, others have built on Deleuze and Guattari's ideas to explore phenomena such as the Occupy Wall Street movement (Barthold, Dunne, & Harvie, 2018) and the rise of subversive forms of strategy (Munro & Thanem, 2018).
While appreciating these prior attempts, we contribute by going beyond the metaphorical use of the rhizome. Instead, we take seriously Deleuze and Guattari's formulation of rhizomatic assemblages, which occupy a central place in their philosophical project, and which they repeatedly contrasted with arborescent assemblages. Our close reading of their work has enabled us to delineate two ideal-typical assembling processes-arborescent and rhizomatic-thereby offering an entirely novel theoretical typology for conceptualizing actorhood. Scholars have highlighted the importance of developing such typologies, which can foster rich theorizing by providing ways to organize and distinguish between complex phenomena (Doty & Glick, 1994). They also challenge simple cause-and-effect relations and instead allow for clusters and configurations which are flexible and potentially equifinal (Delbridge & Fiss, 2013). In line with Cornelissen's (2017) insights, the typology we have developed is deeply embedded in assemblage theory, and this strong philosophical embedding is central to our theoretical contribution.
As anyone who has ever read A Thousand Plateaus can attest, it is a dense text. In this regard, a key contribution of our typology is its synthesis of four overarching principles-association, combination, division, and population-along which assembling may be conceptualized and analyzed. Although it may be tempting to view rhizomatic assembling in overwhelmingly positive terms, we have endeavored to treat both modes symmetrically. Especially notable here are Deleuze and Guattari's (1987) insights on rhizomatic assembling, compactly summarized in the quip: "the vampire does not filiate, it infects" (pp. 241-242). Whereas arborescent assembling entails propagation by means of filiation, heredity, and sexual reproduction, rhizomatic assembling occurs via epidemics, contagion, famine, and catastrophes. This is not a process of translation between codes, but "side-communication," a surplus value of code (p. 53). As the Covid-19 pandemic has shown, rhizomatic assembling has its downsides, too (see also Kuronen & Huhtinen, 2017 on "the rhizome of jihad"). We believe the framework we have developed provides a rich theoretical toolkit for investigating such issues, and perhaps not a moment too soon.
For starters, Deleuze and Guattari (1987) described alliances and pacts as mirroring the form epidemics take in society. Hunting, war, occupation, and crime are all examples of rhizomatic assembling. So too are "minoritarian" groups, as well as groups that are oppressed, prohibited, or "on the fringe of recognized institutions" (p. 247). Such "monsters" constitute a rupture with central institutions. Rather than evolution, Deleuze and Guattari emphasized involution as the mechanism whereby "form is constantly being dissolved, freeing times and speeds" (p. 267). Involution is not regressive, but creative: "To involve is to form a block that runs its own line 'between' the term in play and beneath assignable relations" (p. 239). Although we lack the space to fully explore these observations, an assemblage ontology has much to contribute to academic conversations in areas such as criminal organizations (Cederström & Fleming, 2016;Vaccaro & Palazzo, 2015), stigmatization (Lashley & Pollock, 2019;Zhang, Wang, Toubiana, & Greenwood, 2020), and categories (Bowker & Star, 1999;Garud, Gehman, & Karnøe, 2010).

Conclusion
In Instincts and Institutions, first published in 1955, Deleuze (2004, pp. 19-20) observed: Every individual experience presupposes . . . the existence of a milieu in which that experience is conducted, a species-specific milieu or an institutional milieu. . . . Institution sends us back to a social activity that is constitutive of models of which we are not conscious, and which are not explained either by tendencies or by utility.
In other words, institution precedes actors, and actors are always within institutions. Decades later, Deleuze and Guattari expounded these ideas and grounded them within an original social ontology. Drawing on this work, we have distinguished two ideal-typical modes of assembling actorhood and differentiated them in terms of four principles: association, combination, division, and population. Applying this framework to prior research at the intersection of grand challenges and institutional entrepreneurship, we have identified an arborescent-rhizomatic space in which clusters of arborescent, rhizomatic, and hybrid actorhood exist.
As prior work makes evident, grand challenges manifest within an institutional matrix (Gehman, Lounsbury, & Greenwood, 2016). And yet, despite a central focus on actors, more integrated and programmatic insights have proved elusive thus far. Thus, grand challenges research constitutes a revelatory context for bringing to life our conceptualization of rhizomatic and arborescent assemblages. Our theoretical toolkit provides new possibilities for conceptualizing and comparing these modes of actorhood and their assembling processes. Looking ahead, we see opportunities for further applications of assemblage theory in organization studies and the potential to stimulate new insights on institutional entrepreneuring.


Disorders, Vulnerabilities and Resilience in the Supply Chain in Pandemic Times

: The economic and social environment caused by the COVID-19 pandemic has brought additional pressure on supply chains because they now have more pressure to develop and adapt to a context of economic constraint. Delays in the supply chain can bring consequences such as the lack of food products by retailers, transporters and manufacturers. Thus, this study aims to examine the supply chain during the COVID-19 pandemic in small- and medium-sized food companies in the central region of Portugal, identifying potential problems and pointing out the respective solutions. For this purpose, the study uses a qualitative methodology through semi-structured interviews. It was found that small and medium-sized enterprises (SMEs) do not have a codiﬁed supply chain and that generally, these companies have a minimal budget, which requires a constant search for new suppliers that represent a reduction in costs. Moreover, most of the companies surveyed faced unexpected challenges, such as a lack of alternative suppliers. The present paper is original because it studies the supply chain in SMEs in the food sector during the COVID-19 pandemic, and it allows the ascertainment of practical suggestions for these companies to improve, as well as contributing to the clariﬁcation of the literature on the supply chain in times of crisis such as the current COVID-19 pandemic.

Introduction
A business model is understood as a structure composed of elements, interconnections and dynamics. The Complex Adaptive System (CAS) is one of the most advanced examples of systems theory. The addition of sophistication, flexibility and adaptation allows a CAS to reflect a business model [1]. A business model is composed of eight related resources, including resilience and adaptability, that lie at the boundaries of an organisation [1,2]. The phrase "adaptability causes uncertainty" is central to complex adaptive system (CAS) theory [3]. Stability within organisations through supply chains recognises the ability to withstand shocks in the form of severe events, and companies must establish constructive and reactive behaviour to acquire resilient capabilities to achieve this; that is, to be able to respond effectively to disasters that may occur [4]. The threat of supply disruptions must be considered in contemporary supply chain management. Supply chain delays usually arise with low probability, and however, even if they happen occasionally, they can bring severe consequences to companies [5]. Some researchers have resorted to using expected disruption cost (EDC) as a preparedness tool or metric [6].
Due to the COVID-19 pandemic, supply chains were forced to evolve and learn how to respond to this new society that presents dynamics of increased closure, isolation and restrictions on social and economic interactions. The restrictions imposed to prevent the spread of the virus directly affected the global economy and, consequently, the movement of goods. Pandemics and outbreaks, such as the COVID-19 virus, are possible causes of supply chain disruption [7]. As a result of this context, there have been negative impacts on world trade, with supply chains almost stopping their regular activity altogether. Among the disruptions that result from this, we can include delivery delays and labour shortages. Supply chain managers are aware that materials and commodities necessary to the business are in short supply worldwide. Supply disruptions should be included in current supply chain management and companies should plan their supply chains extensively [8]. They should also focus on keeping resilience balanced with efficiency and cost reduction to predict supply disruptions. The occurrences caused by the COVID-19 pandemic indicate a wide range of risks in the supply chain, where sudden instability affects its long-term development [7].
This study presents as a starting question "What are the most prevalent indicators of disruption, vulnerability and resilience in the supply chain in pandemic times" and focuses on deepening the knowledge about the supply chain when it is in a vulnerable position, either because of the effect of environmental or pandemic crises [9] or because it is in a situation of disruption. We also seek to understand how these companies can be resilient when they encounter these contexts. We analysed the supply chain of five companies in the food sector in Portugal.
Concerning the issues investigated in this work, the selection of suppliers and the ability of those responsible for considering their decision-making are factors considered conducive so that some kind of disruption occurs in the supply chain [5]. In the present study, it was possible to ascertain that supply chain vulnerability received little attention in the literature [10] and that a relationship of an environmental and anthropogenic nature, related to market volatility, prevails, since a notion is felt that a system will recover its initial state after the effect of the factors that affected it [4].
The main results are taken from this study point in the direction that the pandemic that we are going through has dramatically affected these companies' supply chains because they have suffered stock shortages due to the delayed arrival of products in this period. Finally, the companies have relatively low budgets, so they have to search for suppliers according to their budget, which ends up causing obstacles in creating long-term relationships.
However, there are limitations in this study, which prevent us from extracting the maximum knowledge from this subject. The current research was conducted in specific sectors and a particular context. For this very reason, we must limit ourselves to the unique circumstances and refrain from generalising the conclusions. Finally, we point out that the difficulty in defining the customer can be resolved by using a cause-effect relationship system [1]. This paper is structured as follows: It starts with the introduction, which is Section 1 of the article, to present the topic to be discussed. This is followed by a literature review in Section 2, which addresses the issue under study to familiarise the reader with it, address relevant concepts and explore theories. Section 3 presents the methodology followed in this study, and Section 4 presents and discusses the results. Finally, in Section 5, a brief conclusion is shown, where the main results obtained are explained.

Complex Adaptive System Theory
The term "complexity" originated from the Latin "complexus", which means multiple elements. However, some authors consider that the word comes from the Latin "plexus", which ends up meeting Tronca's understanding. This term in Latin means connected. Complexity science refers to a subset of all systems, which are called complex systems. The individual and causal study in these systems are described as trivial. That is, a broad perspective is needed to understand the unpredictability embedded in complex systems.
To facilitate understanding of these systems, complexity science provides complex adaptive systems as support [3,11,12]. A complex adaptive system is made up of several components that communicate with each other. When a mechanism evolves and communicates with the environment, its behaviour changes. The theory studies the characteristics of systems, such as selforganisation and adaptation [13][14][15]. This system is understood to be the suitable model to discuss the complexity present in social sciences today. It is understood as an efficient system that can structure its basic format by resorting to exchanging resources integrated into its environment. They are also able to shape these resources to support action. These systems are usually characterised by path dependency, disorganisation, contingency and adaptability [3,15].
Complexity Theory is a modern way of interpreting current problems [12]. Complex adaptive system (CAS) theory was established in associated studies [3]. Edgar Morin is a vital complexity researcher today who proposed a change in the information model through paradigms of interknowledge in history, geography and law [12]. The author was the first to demonstrate the complexity procedure, starting from his model "Unity in diversity" (1973). This was followed by a Belgian scientist, Prigogine, who introduced "complexity science" [16].
In 1984, the Santa Fe Institute acquired the concept as a slogan and suggested that "adaptability creates complexity." In 1994, the same year that the institute celebrated its 10th anniversary, the development of the complex adaptive system theory was made official by Professor Holland [3]. Equilibrium and predictability are the exceptions, as contemporary research has shown through Complexity Theory. This theory justifies these nonlinear processes, allowing a deeper interpretation of order-disorder equilibrium [14,15].
Real-time planning is a form of complexity theory and allows for real-time predictions [15]. The purpose of CAS theory has broadened from the biological sciences to the social sciences due to its development. This theory is understood to be suitable for analysing decision-making mechanisms and the influence of the interaction of multiple participants [16]. Complexity Theory was referred to as a potential new concept in science [12].
In this theory, due to the relationships/interactions and the new information created by them, the concept of unpredictability appears [11]. As said before, the meaning of this theory focuses on the expression of "adaptability creates complexity," and it presents two levels: micro and macro. As for the micro-level, the individual and the environment can instruct each other using mutual interaction, while at the macro level, the behaviour taken by the subject impacts the environment, which is constantly changing, ultimately limiting the subject's behaviour [16]. After the 1960s, internal and external conditions became increasingly dynamic, putting enormous pressure on business, especially in strategy. Corporations then began to seek flexible, innovative and multi-skilled employees [15].
Wang, Dong, Zhang and Luo [16] drew upon the theory in question, using it as a basis for analysing the matter of low resilience regarding the management of adversity in community public health. These authors emphasise that this theory is applied as a support because of its ability to highlight the relationship between individuals and the environment to improve adaptability to the environment. In the same study, it is suggested to institute a model for community multicultural relationship resilience using the complex adaptive system theory to extend the level of resilience [16]. Some studies aggregate this theory together with fashion [12] and others that refer, in their themes, the theory involved with different companies, applying it to the perspectives of their organisational environment [15].

Business Supply Chain Disruptions
According to the authors, Fahimnia, et al. [17], supply chain managers are subjected to new challenges, such as building a supply chain network that is effective, efficient and resilient enough to overcome disruptions. However, at the same time, it must be sustainable [18]. These disruptions can be caused by natural phenomena such as earthquakes, tsunamis and bad weather, or by the hand of humans [19]. For this reason, the authors also mentioned that supply chain groups tend to deviate from their sustainability purposes while dealing with unpredictable disruption [6].
Authors Sureeyatanapas, Waleekhajornlert, Arunyanart and Niyamosoth [5] agreed that disruptions regarding supply disruptions are expanding among companies. However, with the pandemic that the world is currently experiencing, supply chains have been forced to adapt and adjust to this new closed world. Consequently, a worldwide shortage of essential products and goods has occurred [8]. These events forced companies to change their management and logic in supply chains, alerting them to the changes that needed to be applied if disruptive events of the same kind happened again [8]. Some authors suggest companies perform extensive mapping of their supply chains so that it is possible to predict and anticipate supply-side disruptions [8,20].
Thus, the threat of supply disruptions must be considered in modern supply chain management [21]. Suppose the danger of disruption is related to the supplier choice issue. In that case, it will be unwise to assume that complete data about all the criteria or the complete understanding of the decision-maker regarding the problem are available. The occurrences of disruptive phenomena usually occur with low probability but with high intensity and can be seen as ambiguities concerning the supply chain system [5].
Some authors resorted to using EDC (expected disruption cost) as a metric for planning a resilient supply chain network [22]. For example, suppose there is any supplier that is susceptible to outages. In that case, the responsible individual may choose to go for another one without considering the sustainability factor, i.e., decreasing the risk of outages [6].
Even though the feasibility of disruptions is hard to assess, Lim, et al. [23] concluded that devaluing the probability of disruptions comes out to be more risky/dangerous than overestimating the chance (Mari et al., 2014). The way to maintain a handle on these costs of disruptions, supply chain costs and others is to perform an approach grounded in multi-objective goal planning [6].

Vulnerability in the Supply Chain
In our study, we considered that vulnerability is a variable formed on the outside, and through the size of an impact, or even some kind of damage, it can determine the risk [10]. Associated with the supply chain, it aims to demonstrate the extent to which it is exposed to a disruptive event [24]. Therefore, the vulnerability in the supply chain can be seen when a value movement, if it is exogenous, allows flexibility and can determine the value of product delay [25] and in a product or even during an information-sharing process. However, we can also find it in intangible assets (hardware, software, infrastructure and relations with other companies), as well as in the environment (political issues, such as economic, social, or technological [9]. The risk of inherent invulnerability is found when an interruption is determined. This risk and the ability to withstand a shock and strengthen the supply chain are characteristics by which vulnerability is defined [10]. In this regard, it was necessary to analyse the components (vulnerability and risk) in the case of a disruption. Thus, a graph theory was defined [26].
After the analysis of the components [26], some practices seek to combat vulnerability in the supply chain, such as: proactively manage the risks that the supply chain is subject to, and for this entrepreneurs will need to have methods to identify and measure the possible vulnerabilities, so that they can change factors that coincide with the expected compensation, in terms of risk-reward [27,28]. In a study conducted on the Toyota company, it was clarified that vulnerability might be lower, upon an interruption, if a node degree level (supply chain, in which the network has nodes) is associated with a power law in a supply network structure [26,29].
The concept of resilience, identified as an alternative to control some risks, was studied and worked on in the literature, unlike the little-discussed vulnerability. They only learn to consider and quantify its index and guide the processes involved in optimising the value related to revenue [10,30].

Resilience in the Supply Chain
The word resilience originally comes from materials science. This refers to the ability of a system to recover its initial state after undergoing an elastic deformation without any changes in its nature [31]. Due to market instability, environmental problems and manufactured disasters, the importance of incorporating this concept was emphasised in the operations management scenario [32]. In operations management, resilience is defined as organisational capabilities to face immediate changes in the environment with proactive and reactive actions [33,34].
The first broad study on supply chain resilience began in the UK following transport disruptions due to fuel protests in 2000 and the foot and mouth disease outbreak in early 2001 [35]. The study explored the UK industrial knowledge base on supply chain vulnerabilities and found that: supply chain vulnerability is a major business issue, there is little research on supply chain vulnerability, awareness of the issue is weak and a methodology is needed to manage supply chain vulnerability [35].
Based on this empirical research, Christopher and Peck [36] developed an initial framework for a resilient supply chain. These authors stated that supply chain resilience could be created according to four key principles: (1) resilience can be built into a system before a disruption, (2) a high level of collaboration is required to identify and manage risks, (3) agility is essential to react quickly to unforeseen events and (4) risk management culture is a necessity. Characteristics such as agility, availability, efficiency, flexibility, redundancy, speed and visibility were treated as secondary factors [37].
Given that almost every supply chain faces disruptions of severity and various types, it is important to be prepared for any future disruptive event [38,39]. In a way that allows companies to respond efficiently and effectively and therefore become less vulnerable to disruptions [40]. Therefore, resilience within organisations and across supply chains recognises the ability to absorb shocks in the form of extreme events and the adaptive capacity to adjust to new circumstances and is then recognised as a response capability for a firm's performance as well as a key dimension for a firm's survival [4,41,42].
However, not all risks and impacts are predictable. In this way, if an interruption in the flow of goods or information occurs, there must be an immediate and effective response to minimise losses [36,43,44]. In this sense, to obtain adaptive capabilities to better respond to disasters, companies must develop proactive and reactive actions to overcome the impacts and remain competitive [42].

The Relationship between Adaptive System Complexity and Supply Chain Disruption, Vulnerability and Resilience
Supply chain resilience is related to disruption, vulnerability and the balance of recovery and resilience strategies [45][46][47].
Although several scholars have framed the collection of elements that make up a business model as a system [2], unfortunately, general system theory and system dynamics cannot model the true complexity of the business. That said, related constructs inevitably lack the attributes needed to explain this complexity and dynamism [1].
One of the most evolved forms of systems theory-the Complex Resilient Adaptive System (RCAS)-is proactively employed to prescribe the key considerations that must be addressed in a business model [1].
The introduction of complexity, resilience and adaptation allows an RCAS to represent a business model more accurately than general system theory, with strong alignment between the characterisation of an RCAS and the characteristics of a business environment [1]. Afuah and Tucci [2] defined a business model as a "system made of components, links between components, and dynamics". Andersson, et al. [48] also considered business models in terms of agents, activities and resource exchanges between them, employing goal modelling from the business and information systems school of thought [1]. Itami and Nishino [49] believed that a business model comprises two elements: a business system and a profit model [1]. Baden-Fuller and Haefliger [50] defined the business model as a system involving cause and effect relationships that identify who the customer is, engage with their needs, deliver satisfaction and monetise value [1]. Gassmann, et al. [51] viewed the business model as a system, adopting a systems lens as a theoretical framework to articulate how business model evolution occurs.
The systems theory has framed the notion of resilience as, for example, in resilient infrastructure systems, the ability of an entity or system to return to a normal condition after the occurrence of an event that interrupts its state [52], or perhaps more strategically, to the measure of a system and the ability to absorb ongoing, unpredictable change and still maintain its vital functions [1].
Finally, we consider in this study that a business model is a complex, resilient, adaptive system (RCAS) that is structured in the form of eight interconnected elementary functions, including resilience and adaptation, positioned within the boundaries of an enterprise, which operate in a feedback loop to create and manage value exchange [1].

Methodology
This qualitative study analyses the supply chain in vulnerable interruption situations resulting from the current pandemic context. It also analyses these companies' disruption, vulnerability and resilience to overcome the difficulties arising from this context within their supply chains. A qualitative study was suitable for the present research because observation in natural environments, in this case, allows interpretation and research phenomena such as the functioning of supply chains to understand the processes in the daily life of these companies. Thus, the qualitative method was suitable for this study. It requires a lot of effort and time to analyse the data collected through the interviews because it is a complex phenomenon [53][54][55].
The present study is a multiple case study where we applied semi-structured interviews previously used by Yaroson, Breen, Hou and Sowter [47]. The interviews lasted an average of 40 min. The type of sampling is non-probability by convenience because, for the study, we only considered companies in the central region of Portugal, which is a low-density region, as well as food companies. The strategy used for this study was cross-analysis, taking into account that it is guided by variables with characteristics that do not have quantitative values [55,56].
The companies in this study are SMEs. This aspect is reflected in the data provided by the Pordata platform, as it shows us a higher value, in terms of size, for SMEs than for large companies in Portugal (Table 1). However, the sectors, namely agriculture, manufacturing and restaurants, where these companies are included are in the group of sectors with larger sizes compared to the other sectors. Companies operating in these sectors suffered severe constraints at the various levels of their operations or logistics when the COVID-19 pandemic emerged and its social and economic consequences took hold. The lack of availability of food goods by retailers, transporters and manufacturers has brought consequences such as delays in the supply chain, with almost immediate practical consequences on quality of life and access to consumer goods by the general population, by that the selection of these SMEs becomes even more relevant.

Results and Discussion of the Results
Supply chain disruptions in companies can happen due to environmental factors and human nature [6]. That said, the supply chain, after a disruption, becomes vulnerable [9] and thus needs to recover from these situations, so it needs to be resilient [4].

Supply Chain Disruptions
In Table 3, we can see the results in the theme of supply chain disruptions. The delay in these companies is mostly due to the lack of supply of a food product by suppliers, transporters and producers (C, D, E); the closing of the borders between France and England due to Brexit (in the case of Company B); and due to epidemiological issues (Company A, there was a lack of important protein for the confection of the final product). This delay takes at least five days to three weeks (Company A, B, D, E); only Company C mentions that the product delay happens intermittently due to pandemic issues. In this study, the COVID-19 pandemic was identified as one of the main obstacles, and in the literature, it is also possible to verify its impact on product shortages [8,57,58].  Table 3, it is possible to verify that almost all companies have early warnings as a metric. Only Company C mentions not having any metrics. Companies are discerning the interruption's impact; only Company B takes a day to realise it. They mostly perceive the impact on the sales areas, and Companies D and E refer to the operational area. In the literature, it is also possible to verify metrics, namely the expected cost of interruption, regarding chain planning [6] of risk detection visibility and learning [59,60].
The barriers found in Table 3 for the resolution of the interruption are the lack of alternative suppliers that ensure the same quality (Company A, D, E): one company refers to the fear of not consuming the products they sell (Company C) and Company B refers to the search for new suppliers by customers, which we can see is that it does not allow companies to have close and lasting relationships with suppliers, and this aspect would be very beneficial since it could produce high-quality products [58,61].
The supply chain can be exposed to some disruptive situation, creating a certain vulnerability [24], which can be countered through practices, such as proactive management [28]. Table 4 addresses the theme of supply chain vulnerability, companies characterise their products as perishable products, with possibilities for innovation, as in the example of Company A, which intends to innovate in faster machines to decrease the time of confection of the final product and allows the competitiveness of the company to be increased [62,63].

Supply Chain Vulnerabilities
Moreover, in Table 4, regarding the supply chain, for all companies present, there is almost always the same record of a process initiated by pre-defined contracts with suppliers, then the products are delivered by a carrier, after receipt they are stored, some are processed, others resold until they reach the final consumer. The companies provide directly to the final consumer, and only one delivers by own transport to customers, who promptly sell to the final consumer. The literature also mentioned, in addition to production, optimising maintenance and control to decrease costs [64].
Three companies present amplifying resources; in Table 4, A, D and E, refer to the product shelf life as a resource that amplifies the disruptive activities. Company A still refers to the margin of error of the human factor in the confection of the product, and companies B and C refer to not having amplifying resources. The issue of amplifying stock variation can bring instability, resulting from supply chain dynamics [65].
Four companies report that communication, embedded in management, with the other supply chain members is an asset for the company in a disruption. Only Company D does not consider that its management decision affects a disorder. This internal communication issue is also seen in the literature as a competitive advantage [66].
From both the role of suppliers in a disruptive activity and their role at the time of that activity, only one company stated that suppliers have a function, and that function is to deliver the products needed to achieve that innovation. They exemplified the incremental innovation of the sweet "fradinhas", in which they had to ask suppliers for the products needed for its confection, and again allows a competitive advantage [62,63].
Finally, all the companies refer that the regulatory bodies supervise and inspect the company to provide safety to the final consumers. Two of the companies refer to the ASAE. One refers to GRASP, and one refers to the state veterinarians that supervise the process. Only one company presents a regulatory body that prepares the company to avoid management deficiencies, such as the training provided by the HCCP. It was verified in this study that regulatory bodies serve to eliminate and regulate certain deficiencies in the supply chain, that is, to reduce risks to human health, thus these regulated sectors are entitled to certification to prevent counterfeiting [67].
In this case, the supply chain has to be able to overcome disruptions caused by natural phenomena [6] that the same, created outside [10], cause vulnerability in it. Systems have to recover from these phenomena to stabilise in the initial situation [4]. -Producers (who make the products) -Suppliers who deliver the products to the bakery through their transporters -They store the products -Some are processed, and others resold -Delivery to the final consumer -Conservation; -Expiration date -Mismanagement The role is to deliver the feeds needed to make this innovation happen At the time of the innovation of the fradinhas (new cake made in the company), they had to deliver flour

Good connections with employees and suppliers
Ensure the conservation of products so as not to affect the well-being of final consumers

Resilience in the Supply Chain
The resilience in the supply chain, explicit in Table 5, goes through strategies to prepare and respond to an interruption. All companies report having strategies, where communication and alternative producers or suppliers stand out, where three companies report that it affects customer satisfaction and two companies report optimising time [64,66].
The five companies all highlight resources and process enablers during this event, namely alternative products and suppliers or using products from companies in areas near the companies' location. Four companies, A, B, C and D, have meetings to obtain information from stakeholders, and three companies, B, C, D and E, still incorporate daily phone calls. All companies have information-sharing activities with the other companies [66]. Regarding the competitive position, two of the companies, A and B, intend to ensure market share. Three refer to differentiation in the reduction of time in the preparation of dishes, another company refers to the good management of stock, and lastly, one company refers to the diversification of products [62,63].
All of the companies present the ability to obtain products at the time of disruptive activity, as well as available suppliers. Lastly, obstacles, mainly the COVID-19 pandemic, were referred to by three companies. Company B referred to Brexit and the difficulty in delivering by deadlines since the borders were closed during that time. In a contradictory way, the literature states that the European Union loses little with these types of situations [68]. Finally, four companies present ways to improve the supply chain in disruptive activity through greater knowledge of innovative processes or products by suppliers.
Only Company E refers that there are no ways to improve. The operational part appears in the literature as the area in the supply chain that needs improvement [69].

Conclusions
The present study examined the supply chain in specific companies in the food sector during the COVID-19 pandemic, identified potential problems and pointed out solutions to those problems. The study aims to address the functioning of the supply chain, to integrate the components of vulnerability and resilience, taking into account that good management of the supply chain of companies can increase their competitive advantage.
The main conclusion that can be highlighted is that the interviewed companies are mostly companies that belong to SMEs, which makes them not have a formalised supply chain, unlike large companies, and is later reflected in the lack of metrics. It was also evident that the COVID-19 pandemic affected the companies' supply chains in a harmful way since several delays in the supply of products during that period. In addition to all this, the fact that these companies have smaller budgets forces them to look for solutions, such as constantly seeking low-cost suppliers and maintaining quality, which consequently does not allow the company to maintain long-term relationships with them. Finally, it is also possible to conclude that most companies under study have the same difficulties in solving the interruptions, i.e., the lack of alternative suppliers that can guarantee the same quality in the products.
All companies present several aspects that can be improved. Among them is that many of them identify that suppliers have no function or role in an activity seen as disruptive. In this way, companies could improve this aspect by seeking innovative solutions for their products from their suppliers. They can also improve their supply chain by identifying new suppliers. It would be important to unify all the management in one system because it is important to choose an efficient management system to facilitate the visualisation of each step of the process and improve its supply chain. Another aspect that can always be improved is the greatest possible integration of the whole team involved in the chain. With aligned teamwork, it is possible to reduce operational costs, improve process productivity and manage stock to benefit the entire supply chain. It could be good for companies to analyse previous results (their history) better since this action enables managers to prepare for unforeseen or future failures.
The study's practical implications would be very interesting and valuable for companies to opt for new practices, such as establishing new partnerships. A good example would be to establish partnerships with companies that deliver orders from a smartphone application. These applications usually deliver food, pharmacy products, or even supermarket products. It is an easy way to connect sellers and consumers through couriers who drive the order to the consumer's desired location. Since the companies in this study are all food companies, it would be an added value. From these applications, the companies would reach a larger number of people and consequently make more sales and increase their turnover. SMEs and their employees must adapt to the use of information technology tools and enjoy the advantages of working in a network and a virtual environment. There must be a better use of digital platforms available for this purpose and that best suit their business. These tools should favour the facilitation of communication with customers, cost reduction and business profitability.
Concerning theoretical implications, it can be said that there is very little literature on supply chains in SMEs. This study is important to contribute to the literature of supply chains in SMEs in times of pandemic or crisis. This study compares several companies in the food sector and sellers of perishable products, providing additional value, given the existing scarcity of studies among several companies.
It is also important to mention that this study is original because few studies on this theme applied to SMEs and in the Portuguese context. We highlight that they are all food sector companies, which allows us to make certain comparisons between the companies and understand certain differences between them and their respective supply chains.
Finally, in this study, we present some limitations and indicate possible recommendations for future lines of research. There are always limitations in the study that prevent us from obtaining the maximum and highest quality information possible. One limitation of case studies is that their results cannot be generalised since the present study was applied to specific companies in a specific context. Therefore, we have to stick only to the specific situations and not generalise. Another limitation is the interviewees' interpretation of the interview. The fact that the interview script used has technical terms that many times the interviewees may not understand or are even terms that they do not encounter daily makes it difficult for the interviewees to interpret the meaning, which may lead to a less adequate interpretation of the information and is usually not the information intended by the interviewers. Since the study was conducted during the COVID-19 pandemic, it made the whole process of conducting interviews with more companies difficult.
Although the objective of the present study is ambitious, its fulfillment may point to the need for a greater deepening of the themes under consideration. Issues such as disorders, vulnerabilities and resilience in supply chains can be studied in isolation and in greater depth. To this end, it is suggested that future studies should focus on each of these themes.
In future studies, we also suggest developing other lines of research, not only in a larger number of companies, for example, instead of analysing only SMEs, also analyse micro and large companies. It would be interesting to understand how many existing metrics different companies present to overcome a supply chain disruption. In this way, new metrics that some companies use are made known to other companies, which can support the good functioning of the supply chain within a company. Moreover, as a suggestion for future studies, it would be important to know the characteristics of supply chains, their connections from the point of view of vulnerabilities and the strength and direction of the environmental impact on their resilience. To conclude, we leave some research questions for future studies: Are SMEs able to have a formalised supply chain given their limited resources? What are the effects of supply chain metrics when applied to SMEs?