In this study, we consider the assembly line balancing (ALB) problem which is known as an very important decision dealing with the optimal design of assembly lines. We consider ALB problems with soft constraints which are expected to be fulfilled, however they are not necessarily to be satisfied always and they are difficult to be presented in exact quantitative forms. In previous studies, most researches have dealt with hard constraints which should be satisfied at all time in ALB problems. In this study, we modify the mixed integer programming model of the problem introduced in the existing study where the problem was first considered. Based on the modified model, we propose a new algorithm using the genetic algorithm (GA). In the algorithm, new features like, a mixed initial population selection method composed of the random selection method and the elite solutions of the simple ALB problem, a fitness evaluation method based on achievement ratio are applied. In addition, we select the genetic operators and parameters which are appropriate for the soft assignment constraints through the preliminary tests. From the results of the computational experiments, it is shown that the proposed algorithm generated the solutions with the high achievement ratio of the soft constraints.

1. 서 론
 2. 소프트 할당제약 혼합정수계획 모델
  2.1 요소작업-요소작업 할당제약
  2.2 요소작업-작업장 할당제약
  2.3 소프트 할당제약 혼합정수계획 모델
 3. 소프트 할당제약 GALB 문제를 위한 GA
 4. 성능평가 실험
  4.1 예비 실험
  4.2 본 실험
 5. 결 론
 References

• 최성훈(Depart. of Management Engineering, Sangmyung University) | Seong-Hoon Choi Corresponding Author
• 이근철(College of Business Administration, Konkuk University) | Geun-Cheol Lee