A heuristic for multi-period disassembly leveling and scheduling

We consider disassembly leveling and scheduling for multiple product types with parts commonality. Disassembly leveling, one of disassembly process planning decisions, is to determine disassembly structures that specify parts and subassemblies to be obtained from used/end-of-life products, and disassembly scheduling is the problem of determining the timing and quantity of disassembling products and their subassemblies to satisfy the demands of their parts and/or subassemblies. Unlike the previous studies, we consider the two problems at the same time, especially in multi-period version for the objective of minimizing the sum of disassembly setup, disassembly operation and inventory holding costs. In particular, we consider the general case that disassembly levels may be different for products of the same type and different periods. To represent the integrated problem mathematically, an integer programming model is developed. Then, as an initial solution approach, a simple greedy heuristic using a priority rule is suggested and its performance is reported.