Management discipline studying human transformational processes within organizations
Change management (CM) is a discipline that focuses on managing changes within an organization. Change management involves implementing approaches to prepare and support individuals, teams, and leaders in making organizational change. Change management is useful when organizations are considering major changes such as restructure, redirecting or redefining resources, updating or refining business process and systems, or introducing or updating digital technology. 
Organizational change management (OCM) considers the full organization and what needs to change, while change management may be used solely to refer to how people and teams are affected by such organizational transition. It deals with many different disciplines, from behavioral and social sciences to information technology and business solutions.
As change management becomes more necessary in the business cycle of organizations, it is beginning to be taught as its own academic discipline at universities. There are a growing number of universities with research units dedicated to the study of organizational change. One common type of organizational change may be aimed at reducing outgoing costs while maintaining financial performance, in an attempt to secure future profit margins.
In a project management context, the term "change management" may be used as an alternative to change control processes wherein formal or informal changes to a project are formally introduced and approved.
Drivers of change may include the ongoing evolution of technology, internal reviews of processes, crisis response, customer demand changes, competitive pressure, modifications in legislation, acquisitions and mergers, and organizational restructuring.
History.
Pre-1960s.
Kurt Lewin was a social scientist who researched learning and social conflict. Lewin's first venture into change management started with researching field theory in 1921. Five years later, Lewin would begin a series consisting of about 20 articles to explain field theory. He would go on and publish "Principles of Topological Psychology" in 1936, which was Lewin's most in depth look at field theory. Shortly before his death, Lewin would write two articles called "Human Relations" which are the foundation of his three-step model.
In 1934, Lewin set up a proposal to create an action research-orientated department of psychology at the Hebrew University of Jerusalem. Shortly after, Lewin moved to America and started up other action research initiatives with children, housewives, religious groups, racial intolerance, and leadership. During this time, Lewin became the first psychologist to study group dynamics. His definition of a "group" from this project is still used today; "It is not the similarity or dissimilarity of individuals that constitutes a group, but interdependence of fate."
1960s.
Many change management models and processes are based with their roots in grief studies. As consultants saw a correlation between grieving from health-related issues and grieving among employees in an organization due to loss of jobs and departments, many early change models captured the full range of human emotions as employees mourned job-related transitions.
In his work on diffusion of innovations, Everett Rogers posited that change must be understood in the context of time, communication channels, and its impact on all affected participants. Placing people at the core of change thinking was a fundamental contribution to developing the concept of change management. He proposed the descriptive Adopter groups of how people respond to change: Innovators, Early Adopters, Early Majority, Late Majority and Laggards.
1980s.
McKinsey &amp; Company consultant Julien Phillips published a change management model in 1982 in the journal "Human Resource Management".
Robert Marshak has since credited the big six accounting and consulting firms with adopting the work of early organizational change pioneers, such as Daryl Conner and Don Harrison, thereby contributing to the legitimization of a whole "change management industry" when they branded their re-engineering services as "change management" in the 1980s.
In the late 1980s, General Electric under Jack Welch was somewhat shell-shocked and demoralized following several years of organizational restructuring and de-layering that resulted in far fewer people but the same amount of work, while saddled with a stifling bureaucracy. Welch directed a team that ultimately included Dave Ulrich, Todd Jick, Steve Kerr, and Ron Ashkenas among others, to create a process to "get unnecessary work out of the system." The process became known as Work-Out, which was similar in concept to Quality Circles that were made popular by Japanese companies in the 1980s.
“In small teams, people challenge prevailing assumptions about ‘the way we've always done things’ and come up with recommendations for dramatic improvements in organizational processes. The Work-Out teams present their recommendations to a senior leader in a Town Meeting where the manager engages the entire group in a dialog about the recommendations and then makes a yes-no decision on the spot. Recommendations for changing the organization are then assigned to ‘owners’ who have volunteered to carry them out and follow through to get results. That's Work-Out in a nutshell.” 
“[Work-Out] is also a catalyst for creating an empowered workforce that has the self-confidence to challenge the inevitable growth of organizational bureaucracy. It can help create a culture that is fast-moving, innovative, and without boundaries.”
1990s.
In 1990, "The Fifth Discipline: The Art and Practice of the Learning Organization" by Peter Senge is published. In 1997, Harvard Business Review identified The Fifth Discipline as one of the seminal management books of the previous 75 years. For this work, he was named "Strategist of the Century" by the Journal of Business Strategy, which said that he was one of a very few people who "had the greatest impact on the way we conduct business today." 
According to Senge, there are four challenges in initiating changes:
1. There must be a compelling case for change.
2. There must be time to change.
3. There must be help during the change process.
4. As the perceived barriers to change are removed, it is important that some new problem, not before considered important or perhaps not even recognized, doesn't become a critical barrier.
The first edition of "Managing Transitions: Making the Most of Change" by William Bridges is published in 1991. Bridges emphasized the importance of managing the psychology of transitions, consisting of three phases: letting go of the past, the "neutral zone" where the past is gone but the new isn't fully present, and making the new beginning.
The 1990 oil price shock occurred as a result of the Iraqi invasion of Kuwait on August 2, 1990 and contributed to the recession of the early 1990s in the United States. At General Electric, Jack Welch and the senior leadership team were forced to abandon methodically developed strategic plans. Welch recognized the obvious problem with long-term planning – no one can predict the future. Welch has been quoted by Steve Kerr as saying, “It's not that we're surprised that bugs me, it's that we're surprised that we're surprised that bugs me.” He recognized the advantage of being able to react to change faster than GE's competitors. Welch commissioned a team, including Dave Ulrich and Steve Kerr, to create a process to "accelerate change" throughout GE.
“Thus in 1992 and 1993, some of the external faculty, in collaboration with Crotonville staff, developed and implemented the Change Acceleration Process (CAP) as a follow-up to Work-Out. In this process, drawn from experiences with other companies, teams of managers from a business took on major change projects and learned how to orchestrate an entire change effort.”
In his 1993 book, "Managing at the Speed of Change", Daryl Conner coined the term "'burning platform"' based on the 1988 North Sea Piper Alpha oil rig fire. He went on to found Conner Partners in 1994, focusing on the human performance and adoption techniques that would help ensure technology innovations were absorbed and adopted as best as possible. The first "State of the Change Management Industry" report was published in the "Consultants News" in February 1995.
In the mid-90s, John Kotter authors arguably the most influential publications in the history of Change Management. "Leading Change: Why Transformation Efforts Fail" appeared in a 1995 issue of the Harvard Business Review, and his follow-up book, "Leading Change" published in 1996.
"Who Moved My Cheese? An Amazing Way to Deal with Change in Your Work and in Your Life", published in 1998, is a bestselling seminal work by Spencer Johnson. The text describes the way one reacts to major change in one's work and life, and four typical reactions to those changes by two mice and two "Littlepeople," during their hunt for "cheese." A New York Times business bestseller up on release, Who Moved My Cheese? remained on the list for almost five years and spent over 200 weeks on Publishers Weekly's hardcover nonfiction list.
2000s.
Linda Ackerman Anderson states in "Beyond Change Management" that in the late 1980s and early 1990s, top leaders, growing dissatisfied with the failures of creating and implementing changes in a top-down fashion, created the role of the change leader to take responsibility for the human side of change.
2010s.
In response to lack of understanding in how to manage change in large projects and programs of work, Christina Dean (author of RIMER Managing Successful Change Professional Edition), established the Australian Government National Competency Standards at Diploma Level, and RIMER as the Australian National Competency Standard Certification. RIMER is a Project Based approach to managing change, which introduced the concept of Enterprise Change Management. Christina also influenced the Human Resource Management Institute and Project Management Institute Industry Associations to include Change Management in their Academic programmes to Masters Level. By 2016, all Australian Universities offered programs that provided a formal vocational pathway, through a HRM or Project Management.
In response to continuing reports of the failure of large-scale top-down plan-driven change programmes, innovative change practitioners have been reporting success with applying Lean and Agile principles to the field of change management.
The Lean Change Management Association became the world's first global organization to offer trainings designed to apply Lean Startup, Agile, and Design Thinking principles to change.
The Association of Change Management Professionals (ACMP) announced a new certification to enhance the profession: Certified Change Management Professional (CCMP) in 2016.
Approach.
Organizational change management employs a structured approach to ensure that changes are documented and implemented smoothly and successfully to achieve lasting benefits.
Reasons for change.
Globalization and accelerated innovation of technology result in a constantly evolving business environment. Phenomena such as social media and mobile adaptability have revolutionized business and the effect of this is an ever-increasing need for change, and therefore change management. The growth in technology also has a secondary effect of increasing the availability and therefore accountability of knowledge. Easily accessible information has resulted in unprecedented scrutiny from stockholders and the media and pressure on management. With the business environment experiencing so much change, organizations must then learn to become comfortable with change as well. Therefore, the ability to manage and adapt to organizational change is an essential ability required in the workplace today. However, major and rapid organizational change is profoundly difficult because the structure, culture, and routines of organizations often reflect a persistent and difficult-to-remove "imprint" of past periods, which are resistant to radical change even as the current environment of the organization changes rapidly.
Due to the growth of technology, modern organizational change is largely motivated by exterior innovations rather than internal factors. When these developments occur, the organizations that adapt quickest create a competitive advantage for themselves, while the companies that refuse to change get left behind. This can result in drastic profit and/or market share losses. Organizational change directly affects all departments and employees. The entire company must learn how to handle changes to the organization. The effectiveness of change management can have a strong positive or negative impact on employee morale.
Change models.
There are several models of change management:
Lean Change Management.
Lean Change Management is an ecosystem of modern change management ideas created by Jason Little. Inspired by Lean Startup, Agile, and Design Thinking, Lean Change Management is designed to help change agents create an adaptable, and contextual approach to change
Jason began developing Lean Change Management in 2009 as a response to outdated traditional change management approaches designed in a pre-digital world.
Kurt Lewin's 3-Step Change Model.
Kurt Lewin a German-American psychologist, developed this 3-step model to implement change. The model consists of three steps:
This model of change, developed by Lewin, was a simplistic view of the process to change. This original model "developed in the 1920s and fully articulated in Lewin's (1936a) book Principles of Topological Psychology" paved the way for other change models to be developed in the future.
John Kotter's 8-Step Process for Leading Change.
John P. Kotter, the Konosuke Matsushita Professor of Leadership, Emeritus,