FM 5-0, The Operations Process - Federation of American Scientists

Planning
2-60. In the absence of facts, the commander and staff consider assumptions from their higher headquarters
and develop their own assumptions necessary for continued planning. Assumptions could relate to any
mission variable, such as the strength and disposition of an enemy force or postconflict conditions.
2-61. Assumptions must be logical and reflect the reality of the situation. Commanders and staffs use care
with assumptions to ensure they are not based on preconceptions; bias; false historical analogies; or simple,
wishful thinking. Additionally, planners must be aware of any unstated assumptions.
2-62. Accepting a broad assumption without understanding its sublevel components often leads to other
faulty assumptions. For example, a division commander might assume a combined arms battalion from the
continental United States is available in 30 days. This commander must also understand the sublevel
components—adequate preparation, load and travel time, viable ports and airfields, favorable weather, and
enemy encumbrance. The commander considers how the sublevel components hinder or aid the battalion’s
ability to be available.
2-63. Commanders and staffs continuously question whether their assumptions are valid throughout
planning and the operations process. Key points concerning the use of assumptions include—
• Assumptions must be logical, realistic, and considered likely to be true.
• Too many assumptions result in a higher probability that the plan or proposed solution may be
invalid.
• The use of assumptions requires the staff to develop branches and sequels to execute if one or
more key assumptions prove false.
• Often, an unstated assumption may prove more dangerous than a stated assumption proven
wrong.
PLANNING IS CONTINUOUS
2-64. Even after the operation order is issued, planning continues throughout the operations process. Since
situations (or the information available about them) continuously change, plans are revised as time allows
and variations (options or branches) continue to be developed. Accurately predicting an operation’s
outcome is difficult, as is anticipating the possible contingencies. As planners develop a solution to a
problem, the problem changes. Continuous planning enables organizations to adjust from an existing
concept of operations based on a common understanding of the situation and the expected result. Based on
their assessment, the commander and staff refine and revise the plan during preparation and execution.
PLANNING IS TIME SENSITIVE
2-65. Time is a critical factor in operations. Time management is, therefore, important in planning.
Whether done deliberately or rapidly, all planning requires skillfully using available time to optimize
planning and preparation throughout the unit. Understanding how time affects conducting operations helps
commanders determine how fast and how far ahead to plan. Taking more time to plan often results in
greater synchronization; however, any delay in execution risks yielding the initiative—with more time to
prepare and act—to the enemy. When allocating planning time, commanders must ensure subordinates
have enough time to plan and prepare their own actions.
One-Third–Two-Thirds Rule
2-66. Effective execution requires issuing timely plans and orders to subordinates. Timely plans are those
issued soon enough to allow subordinates enough time to plan, issue their orders, and prepare for
operations. At a minimum, commanders follow the “one-third–two-thirds rule” to allocate time available.
They use one-third of the time available before execution for their planning and allocate the remaining
two-thirds to their subordinates for planning and preparation.
2-67. When time is short, commanders develop the best possible products. In time-constrained
environments, best products contain just enough information for commanders to make a reasoned decision
and subordinates to assess the situation quickly and plan, prepare, and execute the necessary actions. To
26 March 2010 FM 5-0 2-11