The Data Centric Architecture of a Factory Digital Twin
Short duration storage tasks tend to lie upstream of equipment that is not rate limiting . The level of storage activity on the Revo Feed Tanks indicates the tight capacity on the Revo column . Storage patterns on the back end of the process are somewhat irregular because of the uneven pattern of repack tasks ( yellow ).
Figure 5-9 illustrates a solution when we add a 10 % probability of an 8-hour delay to the Revo column ( red colored tasks randomly distributed ). The Revo column is very nearly rate limiting in the absence of random delays and the addition of these delays puts more stress on the storage system . The RevoFeedTank is starting to become a bottleneck about halfway through the schedule . Note that the VirtECS FDT always maintains a one-hour separation between storage of sequential batches as is prescribed for cleaning the storage tanks .
As the TK4356 becomes saturated , slurry from the centrifuge begins to back up into the three Wash Feed Tanks . Due to this storage capacity , the back end of the process is still able to keep up with the front end , no gaps are induced on the true bottleneck , the 10,000-liter bioreactors . If the available storage had been inadequate , the random delays would have impacted process capacity . This is the sort of complex and subtle effect that can only be foreseen with a highly detailed FDT . If detected in the plant design phase , steps could be taken to determine the most cost-effective process modifications to alleviate the problem .
Figure 5-9 : Addition of a 10 % probability of an 8-hour delay .
6 THE VALUE OF FACTORY DIGITAL TWINS
Determining the value of an FDT is challenging . Essentially two timelines must be sampled for the real process . One timeline in which the FDT is used to manage the real process and an alternate
Journal of Innovation 117