There are four types of plans. Implementation planning is the most widely used planning method. Other types of plans take into account factors beyond the company's control. Implementation planning, however, because of its short-term focus, assumes the future is stable. Budgets are variations of implementation planning.
Contingency planning aims to generate options for the firm if the company's intentions go wrong.
Scenario planning takes for granted the future is unknowable in detail. Nonetheless, scenario planning presumes executives can imagine different futures, especially unpleasant ones. Because no plan is viable in all possible futures, scenarios reveal weaknesses in the company's products or position as executives analyze their strategies in different futures. For example, human resource forecasting is difficult because so many factors influence the demand for workers and the supply of qualified employees. Vector Research devised a forecasting method for a national educational organization that wanted to see the implications of an undersupply of teachers.