An Improvement of Instance Generator Featuring Assembly Operations with Parallel Machines for Multi-Level and Multi-Operation Scheduling Problems

This paper proposes an improvement of instance generator for scheduling problems called i-IGSP. There are three significant improvements from the existing IGSP. The first feature is the main contribution of this paper, which is the integration of an assembly operation option with parallel machines to all types of multi-level and multi-operation production shops, known as flow shop and job shop. These shops have been found in many modern industries and scheduling researches at the present. The second feature provides the choice of due time scenarios. The third enhancement makes the output text files more consistent and for all production shops. Based on the improvements, i-IGSP has become one of the most completed instance generators for scheduling problems than the other instance generators published in the literature. Researchers can use it to not only to evaluate their algorithms and generate benchmark problems but also to save time and cost of data collection from real industries.