This paper deals with the problem of scheduling jobs and rate-modifying activities on parallel machines, motivated by a problem commonly found in the surface-mount technology of electronic assembly lines. A rate-modifying activity involving repair, maintenance and readjust is an activity that changes the production rate of equipment under consideration. In this paper, the processing time of a job scheduled before the activity is equal in each parallel machines. On the other hand, if the job is scheduled after the rate-modifying activity than the process time depends on the modifying rate of the activity. Our purpose is to schedule the rate-modifying activities and jobs to minimize the makespan on parallel machines which is NP-hard. We propose a branch and bound algorithm to solve medium size problems optimally. Also we develop three heuristics, Modified Longest Processing Time (MLPT), MULTIFIT and COMBINE algorithms to solve large size problems.

Abstract
 1. Introduction
 2. Literature survey
 3. Problem statement
 4. Solution approach
 5. Experimental results
 6. Conclusion
 Reference

• 조항민(한양대학교 산업공학과)
• 정인재(한양대학교 산업공학과)