An algorithm for minimizing weighted earliness penalty in assembly job shops

This paper addresses the problem of minimizing the weighted earliness penalty in assembly job shops. A job in the shop is assumed to have a tree product structure consisting of components and subassemblies and that each component or subassembly may need additional processing before it can mate with other parts. As is typical in just-in-time production, no tardy job is allowed. Because of the computational time intensity associated with the problem, a heuristic was developed to solve the problem. Optimality conditions were derived and used in the development of the heuristic. The heuristic decomposes the problem into several single machine problems. Solutions to the single machine problems were used to construct the solution to the original problem. The effectiveness of the heuristic was evaluated by solving a set of test problems. The results of the test problems demonstrated that the heuristic is effective in solving the problem.