Scheduling with Job Dependent Learning Effect and Ergonomic Risk Deterioration

In this study, new types of deterioration related to ergonomic risk factors in machine scheduling problem are investigated. By the ergonomic risk, we mean that the employees are exposed to risk of work related musculoskeletal disorders (WMSD) for the reasons of repetitive activities. Rapid The Upper Limp Assessment (RULA) was used to assess the WMSD risks. We accepted that the deterioration and the processing time are related to the ergonomic risks. Given that the learning effect is ignored and the RULA score value is equal to zero, the actual processing time is equal to the basic processing time. As the level of ergonomic risk increases, processing time is prolonged. In this study, makespan minimization on single machine scheduling problems were handled. Job dependent learning effect and ergonomic risk deterioration is included to assignment problem model. Ergonomic risks are designed as a composite risk index in the assignment problem model. The composite risk index means that effects of all the technical activities within the shift carried out are until the end of the shift. Designed assignment problem models are solved with the help of LINGO. In this study, it has been shown that the scheduling problems that are handled with composite risk-indexed deterioration and work-dependent learning effects remain solvable.