Kharazmi University International Journal of Supply and Operations Management 23831359 3 1 2016 05 01 Modeling the Hybrid Flow Shop Scheduling Problem Followed by an Assembly Stage Considering Aging Effects and Preventive Maintenance Activities 1215 1233 2669 10.22034/2016.1.07 EN Seyyed Mohammad Hassan Hosseini Industrial Engineering and Management Department, Shahrood University of Thechnology, Shahrood, Iran 0000-0002-6164-3179 Journal Article 2016 07 21 Scheduling problem for the hybrid flow shop scheduling problem (HFSP) followed by an assembly stage considering aging effects additional preventive and maintenance activities is studied in this paper. In this production system, a number of products of different kinds are produced. Each product is assembled with a set of several parts. The first stage is a hybrid flow shop to produce parts. All machines can process all kinds of parts in this stage but each machine can process only one part at the same time. The second stage is a single assembly machine or a single assembly team of workers. The aim is to schedule the parts on the machines and assembly sequence and also determine when the preventive maintenance activities get done in order to minimize the completion time of all products (makespan). A mathematical modeling is presented and its validation is shown by solving an example in small scale. Since this problem has been proved strongly NP-hard, in order to solve the problem in medium and large scale, four heuristic algorithms is proposed based on the Johnson’s algorithm. The numerical experiments are used to run the mathematical model and evaluate the performance of the proposed algorithms. Scheduling Hybrid flow shop Assembly Aging effects Preventive maintenance activities http://www.ijsom.com/article_2669_40f535377d1bc0b0f758753062e5056e.pdf