Realizing the Benefits of Finite Capacity Scheduling to Manage Batch Production Systems

by Glen Wirth and Marcus Tennant, Rockwell Automation, and Vincent de Gast, Systems Navigator The most common scheduling tools are spreadsheets and batch lists, that are manually updated and do simple calculations, or ERP systems, that tell you what is needed, what is available, and what is required. The limitations of these tools, for batch lists, are that intensive manualinput necessary to create an accurate schedule; they only often model operations on a higher level, and they assume infinite or fixed rewpource capaiblities. The realtime capacity of the facility is not considered, and they can't model many types of constraints. They can't model bottlenecks, WIP etc., and they can't compare models against each other. Finite Capacity Schedule accurately models manufacturing facility, and provides visibility in to future events, with defined, detailed production schedles based on KPIs...it does nto replace ERP, it complements and adds value to the ERP's functionality. FCS in Batch: It provides visibility across batch process, by linking together multiple batch systems, with bulk and packaging scheduling, pegging of process orders and understanding of the impact of upstream and downstream ops/orders. Modeling of batch constraints with resources sets, constraints and operational constraints. Through Finite Capacity Scheduling we're able to visualize the entire batch process. We can see what effect a change made in bulk processing will have on packaging lines. This is a powerful way to run What If? Scenarios. Flexibility is enhanced, gaps are removed. We can reduce WIP, and improve performance. Most data to run FCS exists with other systems. ERP has teh master data, and the batch system has the transactional data. FCS defines which batch to run, when they should be run and what resources should be used. Schedule of batches should be followed; runing batches out of sequence could impact the performance of downstream operations. Under certain cases, batch system can override schedule. Actual information is necessary to adjust the FCS system. Data accuracy and timeliness are important for success. Data should be event based. B2MML simplified integration. B2MML standard is a well known canonical data model. It hides the complexities of each application's API. Interfaces  are extended based on a design pattern. B2MML schemas represent all the data necessary to integrate ERP, FCS and Batch systems. Other keys for success: Start with a simple initial model-- don't get caught up with all the details. Get ample feedback from the production floor, and link scheduling rules to business objectives. Provide means to easily modify scheduling rules, and develop reports to measure schedule performance based on KPIs. Add parameters to adjust the rules, and expose scheduling logic so it can be modified. Use what-if scenarios to test the rules. There are limitations in the current set of scheduling tools FCS ssystems provide a robust framework for modeling batch productuion systems. Modelling constructs can be used to imrpove batch production performance (cycle time, reduce infventory, increasedd utilization). Visibility across thee entire batch production process, scheduling rules based on KPIs, and use the ability of B2MML.