Hybrid Flexible Flow Shop Scheduling (HFFS) Instances

These instances represent the Hybrid Flexible Flow Shop Scheduling Problem (HFFS) with multiple sequential stages, each potentially containing several parallel machines. Each order contains a set of jobs which must be processed through these stages, and machines may have different processing capabilities, introducing flexibility in job assignment. Each machine is associated with work-in-progress (WIP) inventories of limited capacity which are used to temporarily store completed jobs before moving to the corresponding machine of the next stage. Additionally, machine-dependent transportation times between the stages are considered. Finally, each different instance consists of 3 separate days. The objective set of this problem is to minimize the makespan, i.e., the total completion time of all jobs. The scheduling must account for machine availability, processing times, WIP inventory constraints, and transportation times to determine an efficient job sequence and assignment. Different datasets of diverse size have been created, based on the number of orders and the number of stages.