A hybrid algorithm of product-service framework for the multi-project scheduling in ETO assembly process

Abstract

The engineer-to-order (ETO) production strategy plays an important role in today’s manufacturing industry. This paper studies the multi-project scheduling in assembly process of ETO products. The multi-project scheduling problem is to schedule tasks of different projects under many constraints and assign hierarchical workers to each task. We develop a mathematical model to represent the problem. In order to solve with the minimization of makespan as the objective, we propose a hybrid algorithm combining particle swarm optimization (PSO) and Tabu search (TS). The improved PSO is designed as the global search process and the Tabu search is introduced to improve the local searching ability. The proposed algorithm is tested on different scale benchmark instances and the case that uses industrial data from a collaborating steam turbine company. The results show that the solution quality of the hybrid algorithm outperforms the other three algorithms proposed in the literature and the experienced project manager.