Skill-based worker assignment in a manual assembly line
Iris Gräßler, Daniel Roesmann, Chiara Cappello, Eckhard Steffen
Abstract
In human-centered assembly systems, workers adapt to new and changing tasks based on learning processes. Human factors are crucial for the entire system capability in such kind of systems. Current methodologies of assembly scheduling often take only limited account of human factors and the interaction between assembly scheduling and workforce planning. Although extensive research indicates that a careful introduction of human factors implies many benefits, examples are reduction of errors, increasing flexibility and performance of the system as well as increasing human wellbeing. The developed methodology addresses the research gap in modeling the impact of human factors on assembly scheduling. In the paper at hand, human factors are systematically integrated into assembly scheduling. This is done by adapting the learn-forget curve model of Jaber and Bonney. In addition to experience, learning and forgetting, the age and the accordance of assembly operations are considered. Within the scheduling model of worker assignment, two coordination approaches are followed. On the one hand, skill-based assembly planning with a long-term perspective and on the other hand, time-based assembly planning with a short-term perspective is proposed. The developed mathematical model assists planners in the assignment of workers to workplaces in a manual assembly line by predicting performance based on human factors.