Papers by Author: Zhi Qiang Lu

Abstract: In this paper the multiprocessor task scheduling problem with variable job profile is addressed. Such problem originates from many practical resource assignment contexts. Based on discretized parameters, the problem is formulated as an integer programming model. Due to the complexity of the problem, a Lagrangian relaxation is applied to solve the problem. The numerical experiment demonstrates the effectiveness of our algorithm procedure.

Abstract: We integrated run-based preventive maintenance (PM) into the production plan at the tactical level. The production plan was based on the single level capacitated lot-sizing problem (CLSP). We assumed the system reliability should be kept above certain threshold value to ensure the feasibility of the production plan; the reliability would be affected only by system running. Thus, PM would be triggered by the reliability requirement and the accumulated running time. We established this relationship as a nonlinear integer constraint in the joint model. We also proposed a branch and bound algorithm using CPLEX to solve the model. Finally, a numerical example was given to illustrate the difference between run-based and time-based PM.