This paper proposes a new approach for solving the production planning and scheduling problem called "Goal Programming adproach to Hierarchical Production Planning". This approach combines the attractive feature of both goal programming as a powerful tool for multi-objective analysis and the hierachical system as an effective framework for decision making in a single-stage batch pro cessing environment.
The proposed procedure assumes that there are two levels of the pro duct aggregation in the production structure from the Hax and Meal framework [8]. Production items may be aggregated into families and families aggregated into types. Type is a collection of items that have the same demand pattern, the same unit costs, direct costs (excluding labour costs), holding costs per unit per period, and the production time required per unit. A family is a set of items within a type such that the items share a common setup. This form of aggregation may result in partitioning the production planning and scheduling problem into two subproblems in a hierarchy. The two subproblems are the aggregation production planning subproblem and the family disaggregation subproblem. The aggregation production planning subproblem, the highest level of planning in the hierarchical system, is concerned with the effective allocation of production resoures amongst product types to satisfy demand over a specified planning horizon. Typical decisions to be made at this level are the determination of production and inventory levels for each product type and regular and overtime workforce levels in each time period. The family diaggregation subproblem, the second level of planning, is concerned with the disaggregation of aggregate production plan for each type into production schedules for families belonging to that type over a short scheduling horizon. Typical decisions to be made at this level are the determination of production and inventory levels for each family within a type in each time period in the scheduling horizon.