Real-time dispatch gets real-time results in AMD's Fab 25

The complexity of microprocessor fabrication never ceases to challenge us. Re-entrant flows, multiple technologies, shorter lead times and high dollar equipment sets increase the difficulty of making critical dispatching/scheduling decisions. When these decisions are made based on incomplete or out-of-date factory data, line balance and equipment utilization may suffer which can greatly affect productivity and cycle time. At AMD we view our dispatch system as the future means to control our cycle time and performance to mix (shipping exactly what we commit to our customers). Our old dispatch system however did not provide the capability or the flexibility that would allow us to apply customized logic to managing our material flow. As the pressure to reduce cycle time and increase performance to mix became more apparent, the search for a real-time, rules based dispatch tool began. The search itself was successful. In the beginning of 1997 AMD was the first company in North America to implement the Real Time Dispatch (RTD) system from AutoSimulations Inc. (ASI). This new dispatch tool utilizes real time factory system data in the execution of customized dispatch rules. ASI as an expert company in discrete-event simulation also provides a testing environment for dispatch rules that links with fab simulation models which allows for the development and testing of rules without jeopardizing production. The following paragraphs discuss in detail why we felt we needed a better dispatching tool, provide an overview of the RTD system, and finally present a case study of our experience applying RTD to AMD's Fab25.