DECISION-SUPPORT SYSTEM FOR LUMBER PROCUREMENT AND DRY KILN SCHEDULING

Furniture producers are implementing small-lot, rapid-response product ion policies. In this environment, determining the optimal timing and mix of lumber purchases, controlling lumber inventory levels, achievin g high kiln utilization, and satisfying demands for dried lumber in a timely fashion is more difficult. To address this problem, a lumber pr ocurement and kiln scheduling decision support system has been develop ed. Dry kiln scheduling is modeled as a set of n independent and Iron- preemptive jobs processed on in non-identical, parallel machines (kiln s) with the objective of minimizing the total weighted tardiness of lu mber demands. Since optimal solutions are difficult to obtain and may not meet all the due dates, heuristic algorithms have been developed t o generate efficient lumber demand/kiln assignment sequences in a mult i-period planning environment. The heuristics have been incorporated i nto a decision support system providing interactive assistance in dete rmining a plan for purchasing and drying lumber that meets demand requ irements and minimizes total costs. The decision support system 1) gen erates solutions for the sequence, timing, and content of each kiln ch arge, based on satisfaction of due dates; and 2) evaluates the costs o f obtaining kiln-dried lumber from alternative sources (e.g., drying g reen or air-dried lumber or purchasing kiln-dried lumber).