Approaches to Modeling of Multiproduct Batch Plants

The approaches and tools utilized for modeling and scheduling of multiproduct batch plants vary widely. A possible grouping of the approaches based on tools utilized follows  

People manually color Excel cells to represent the equivalent of equipment occupancy charts for consecutive batches. Some users have implemented scripts that color cells based on batch recipe descriptions as well. Very little sophistication is required for the user. However, this approach is time consuming, cannot be very detailed, and cannot be readily updated to account for delays and equipment failures. Nevertheless, it is probably the most common approach at the present. 

BATCHES and Aspen Batch Process Developer can be used to model multiple batches of multiple products. However, they take a long time to generate solutions because they do detailed material and energy balances for all the simulated batches. Furthermore, these tools cannot easily accormt for equipment failures, delays, work shift patterns, downtime for equipment maintenance, holidays, etc. Consequently, they cannot be used for day-to-day scheduling of multiproduct plants. 

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