Equipment occupancy chart for three consecutive batches

Equipment occupancy chart for three consecutive batches 

Scheduling and cycle time analysis in the context of a simulator is fuUy process-driven and the impact of process changes can be analyzed in a matter of seconds. For instance, the impact of an increase in batch size (which affects the dmration of charge, transfer, filtration, distillation, and other scale-dependent operations) on the recipe cycle time and the maximmn nmnber of batches can be seen immediately. Due to the many interacting factors involved with even a relatively simple process, simulation tools that allow users to describe their processes in detail, and to quickly perform what-if analyses, can be extremely useful. 

If this production line operated around the clock for 330 days a year (7,920 h) with its minimum cycle time of 62.1 h, its maximum annual number of batches 

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Figure 15.5 displays the Equipment Occupancy chart for three consecutive batches of the process (each color represents a different batch, and the individual procedures associated with Batch 1 are labeled). The process batch time is approximately 92 h. This is the total time between the start of the first operation of a batch and the end of the last operation of that batch. However, since most of the equipment items are utihzed for shorter periods within a batch, a new batch can be initiated every 62.1 h. This is known as the minimmn cycle time of the process. Multiple bars of the same color on a given line (e.g., for R-101, R-102, and NFD-101) represent reuse (sharing) of equipment by multiple procedures. White space between bars represents idle time. The equipment with the least idle time between consecutive batches is the time (or scheduling) bottleneck (R-102 in this case), which determines the maximum number of batches per year. Its occupancy time (62.1 h) is the minimum possible time between consecutive batches. In contrast, the occupancy time of R-101 is 61.3 h, so there is a small gap between batches in this rmit. 

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