DES greatly helped in determining the new surge tank sizing, point-of-use and distribution loads along with target supply flow rate. The modeling clearly showed the interactions and impact of the new system on the existing one, allowed running multiple scenarios very quickly, enabled incorporating stochastics (variability) into the analysis, provided good visual outputs so individuals could easily understand the results, and facilitated a robust design that had good analysis and data supporting the recommendations.
A GROWING ROLE
DES is a very powerful simulation approach that's being used extensively at Eli Lilly and Company to model the flow through real processes. It's helping the company make better decisions about the impact of proposed changes and hence where we can use our resources more effectively. The advent of good tools in recent years has increased the application of DES by enabling more personnel to build these simulations and make them available to the organization. As more successes accumulate, we expect this trend to continue.
BERNARD MCGARVEY, Ph.D., is process modeling group leader for Eli Lilly and Company, Indianapolis, Inc. RICHARD DARGATZ is an associate senior consultant engineer for Eli Lilly in Indianapolis. DAVID DZIRBIK is an associate senior consultant engineer for Eli Lilly in Indianapolis. E-mail them at McGarvey_Bernard@lilly.com, Dargatz_Richard_G@lilly.com and Dzirbik_David_J@lilly.com.
The authors would like to thank Roger Scott, Eli Lilly and Company, for his input.
1. Cope, D., "Consider Discrete Event Simulation," p. 27, Chemical Processing, Oct. 2010, online at www.ChemicalProcessing.com/articles/2010/178.html.
2. McGarvey, B. M., Dynes, N. J., Lin, B. C., Anderson, W. H., Kremidas, J. P. and Felil, J.C., "A Discrete Event Model Of Clinical Trial Enrollment At Eli Lilly And Company," Proceedings, 2007 Winter Simulation Conference, Washington, D.C.