A plan is typically any procedure used to achieve an objective. It is a set of intended actions, through which one expects to achieve a goal. Plans can be formal or informal:

• Structured and formal plans, used by multiple people, are more likely to occur in projects, diplomacy, careers, economic development, military campaigns, combat, or in the conduct of other business.
• Informal or ad-hoc plans are created by individuals in all of their pursuits.

A lack of planning in any discipline may lead to a misallocation of resources, misunderstandings, or irrelevant sections added to Wikipedia articles such as this one.