Improving schedule robustness in a chemical batch company

The subject of this thesis is improving the schedule robustness at ESN. ESN is facing the problem that frequent uncertain events cause the necessity for rescheduling. Besides, the decision support systems that are currently used do not provide sufficient support to take substantiated rescheduling decisions. This way, ESN is subject to ever returning complications that require much efforts by the planning department and managers. ESN uses multipurpose equipment to produce a large variety of products that follow different routings through the plant. Products differ with respect to the number and duration of the required jobs. In addition, the demand volume per product is low and highly variable. Therefore, production planning and scheduling is highly complex. Besides, the production system is subject to many uncertain events that negatively impact the execution of the schedules. Consequently, reschedules are frequently needed to fix the schedules. Unfortunately, decision making about reschedules is hard because the tools that are used do not provide sufficient insights. This results in highly nervous schedules. Therefore, the aim of this thesis is to find a way to reduce the schedule nervousness by creating more robust schedules.