An Integration of Static and Dynamic Capacity Planning for a Ramping Fab

In the semiconductor industry, production planning is often complicated due to constantly changing product mixes, reentrant process flows, and high variations of capacity uptime. In this paper we discuss the combination of static capacity and dynamic simulation approaches for production planning, highlighting how these approaches complement each other in our daily business process. The typical static capacity planning is based on a fixed product lead time, allocating the production volume of each product to available capacity with an objective of capacity minimization and a constraint of utilization limit (plan load limit) to absorb production variability. Whereas the dynamic simulation models the process of lots flowing through the production line, and consume the capacity at each process steps, with additional consideration of fab WIP at the beginning of simulation. With simulation we can additionally provide forecasts for important production key figures, for example product cycle times and fab flow factor.