Table 1: Existing statistical WIP forecasting steps.

StepDescription

1Given the process flow name of product is , retrieve all process steps for
2For each process step in , get the turn-around-time of , ; this value is predefined in the manufacturing execution system (MES) of the fab.
3Let denotes the total photolithography layers in , denotes the number of photolithography layers in completed per day, the day-per-mask-layer (DPML) committed for , is denoted as
denotes the total turn-around-time (TAT) for , denoted as
The run rate for , is
4Cycle time (CT) for a process step , is
5For each lot, sum the next steps of until the CT reaches 24 hours. The last would be the forecasted destination step of the lot after 24 hours
6To forecast the destination step of the lot for the next day, sum the next steps of until the CT reaches hours. The last would be the forecasted destination step of the lot for the next day