Issues in Specifying Planning Horizons for Production Planning within CIM Environments

Abstract

The development of production plans for the CIM hierarchy directs the firm’s manufacturing activities over an extended time horizon. All of the subordinate CIM functions (e.g. production scheduling, material and capacity requirements planning, purchasing, and others) are impacted by this plan. The first step in the development of a production plan is the specification of an appropriate planning horizon--a complex task that is plagued with numerous uncertainties. To address this task, this paper views the production planning problem as a two-point boundary value problem where boundary conditions must be specified at both the beginning and at the end of the planning horizon. A difficulty arises in the specification of the ending boundary conditions since they are generally unknown. Furthermore, an incorrect specification can have a significant, perhaps detrimental, effect upon the quality of the developed plan. An additional requirement for the planning horizon is that it be of suitable duration to permit an effective integration of production planning with the other CIM functions.