Bi-objective optimization for Scheduling and Multi-skilled Worker Assignments in the Hybrid Flow Shop

This paper investigate a bi-objective scheduling and worker assignment problem in a hybrid flow shop. The difficulty of this problem lies in four aspects: (i) the workers differ with each other in both the quantity and proficiency of their acquired skilles; (ii) each processing stage is comprised of parallel unrelated machines; (iii) sequence dependent setup time should be considered and respected; (iv) both the makespan and the total flow time should be minimized simultaneously. To solve this bi-objective optimization problem, we first formulate it into a mixed integer linear programming model, then the commonly used exact solution method 6-constraint method is adopted to solve the model. A small instance is randomly generated and tested, the testing result demonstrates the effectiveness of the proposed model. (C) 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.