text: Operational Art and Science
  2-22. A line of effort is a line that links multiple tasks using the logic of purpose rather than geographical
  reference to focus efforts toward establishing a desired end state (ADP 3-0). Lines of effort are essential to
  long-term planning when positional references to an enemy or adversary have little relevance. In operations
  involving many nonmilitary factors, lines of effort may be the only way to link tasks to the end state. Lines
  of effort often enable commanders to visualize how military capabilities can support the other instruments of
  national power.
  Tempo
  2-23. Commanders and staff consider tempo both when planning and executing operations. Tempo is the
  relative speed and rhythm of military operations over time with respect to the enemy (ADP 3-0). It reflects
  the rate of military action. Controlling tempo helps commanders keep the initiative during operations. During
  large-scale combat, commanders seek to maintain a higher tempo than the enemy does; a rapid tempo can
  overwhelm an enemy’s ability to counter friendly actions. During other operations dominated by stability
  operations tasks, commanders act quickly to control events and deny enemy forces positions of advantage.
  By acting faster than the situation deteriorates, commanders can change the dynamics of a crisis and restore
  stability.
  2-24. Several factors affect tempo, including sustainment and decisions on when and where to consolidate
  gains. Having adequate forces to consolidate gains simultaneously while maintaining the offense enables
  greater tempo. This is a key consideration for theater-level planning when determining force allocation and
  tailoring in support of operation plan development. Commanders and staffs use effective planning to
  accelerate tempo by anticipating decisions and actions in advance. This emphasis on increased tempo, while
  a guiding principle, is not an unbending rule. Commanders weigh the advantages of acting more quickly
  against the advantages of preparing more thoroughly. Army forces expend more energy and resources when
  operating at a high tempo. Commanders assess their force’s capacity to operate at a high tempo based on its
  performance and available resources. An effective operational approach varies tempo throughout an
  operation to increase endurance while maintaining speed and momentum. There is more to tempo than speed.
  While speed can be important, commanders balance speed with endurance and reach.
  Phasing and Transitions
  2-25. Commanders and staffs use planning to determine the sequence of actions—including the phases and
  transitions—that best accomplishes the mission and achieves the desired end state. Ideally, commanders plan
  to accomplish a mission with simultaneous and integrated actions throughout their area of operations (AO).
  However, operational reach, resource constraints, and the size of the friendly force limits what units can do
  at one time. In these cases, commanders phase operations. Phasing provides a way to view and conduct
  operations in manageable parts.
  2-26. A phase is a planning and execution tool used to divide an operation in duration or activity (ADP 3-0).
  Within a phase, a large portion of the force executes similar or mutually supporting activities. Achieving a
  specified condition or set of conditions typically marks the end of a phase. Commanders phase operations as
  required by the specific circumstances of the problem they are trying to solve. A change in phase usually
  involves a change of mission, task organization, or rules of engagement. Phasing helps in planning and
  controlling operations during execution. Phasing may be indicated by time, distance, terrain, or an event.
  Well-designed phases—
  * Focus effort.
  * Concentrate combat power in time and space at a decisive point.
  2-27. Transitions mark a change of focus between phases or between the ongoing operation and execution
  of a branch or sequel. Shifting priorities among the offense, defense, and stability also involves transitions.
  Transitions require planning and preparation so the force can maintain the initiative and tempo of operations.
  Transitions normally occur whenever there is an abrupt change to an OE, threat, or friendly forces.
  Transitions can be planned or unplanned, but any transition creates a period of vulnerability for the side in
  transition.
  2-28. Unplanned transitions present the most danger to a force. Whenever possible, leaders must anticipate
  transitions through effective planning and preparation, and they mitigate or exploit their effects accordingly.