Dynamic Sampling Plans using a Metrology Situation Indicator (MSI)

Sampling plans are expected to adapt to manufacturing dynamics as well as to real-time changes in a metrology workshop. To address this problem, we model sampling plans to reflect the three typical transition states of sampling contexts – normal, high risk and capacity crisis. To allow the inference of a capacity crisis state, a novel indicator called the Metrology Situation Indicator (MSI) is proposed. Skip or sampling rates can be modified across all sampling contexts in a metrology workshop using the MSI via crisis factors. This allows the real-time adaptation of metrology WIP (Work In Progress) to metrology capacity. The design and industrial deployment of this indicator is discussed. Results show that using the MSI improves the metrology Overall Equipment Efficiency (OEE) by up to 5% without any significant impact on the overall Fab cycle time as the waiting time is incorporated in the MSI.