Multi-station Job Shop Scheduling with Operations Overlapping

A new problem of job shop scheduling with multi-station processing arisen from the small and precision industry was addressed, which can fix more than one jobs at a workcenter once. The jobs that synchronously set up at the multi-station were denoted as a group and the same jobs were classed as a batch. A batch processing time was divided to several group processing time. The problem's objective was to minimize the total completion time C(max). A hierarchy strategy was introduced: the shortest processing time first rule (SPT) was applied to sequence the operations of all jobs and a foreword constraint satisfaction algorithm (FCS) was used to restore the operation of the group jobs and came out an overlapping group operation schedule. Later, the developed algorithm was tested on real-world data obtained from a hard disk company.