OVERVIEW OF SCHEDULING PROBLEMS WITH LEARNING EFFECT, DETERIORATING EFFECT, MAINTENANCE ACTIVITY AND NON- MONOTONIC TIME-DEPENDENT PROCESSING TIMES

In recent times many research has been focused on assumption that processing times of a job is unfixed. In practice, thus the processing time ofa job processing time of a job may changes due to some factors. We investigated factors that affect the varying processing time of a job under different machine environments. We were able to identify four factors that may influence processing time of a job, these include learning effect, deteriorating effect,maintenance activity and non-monotonic time-dependent processing time. In this paper, we discussed machine environments and their assumption and some features of jobs processing times. We also gave a concise overview on the literature on scheduling with learning effect, deteriorating effect, maintenance activity and non-monotonous time dependent processing times. The emphasis was on single machine, parallel machine and flowshop machine while few work are done on open shop and job shop machines. We discovered that these factors are never been considered simultaneously. Dynamic programming and machine learning approach methods are not been used while hybrid meta-heuristics methods are scarcely used in all the machine environments under these constraints