Upper Control Limit - of a Control Chart calculated based on the average range (within subgroup) and the grand mean (between subgroup) of the data.
Uncoded Matrix
The matrix of factors with their values in actual units (recommendation is to analyze DOE’s with coded factor levels, e.g. –1 & +1)
Underutilization of People
One of the 8 Wastes. This waste can be seen in two ways: 1) not optimizing peoples time, 2) not utilizing people’s talent, education, skill, experience…
Uptime
Amount of time a machine can work defined as Total Available time – planned machine down time.
USL
Upper limit of the engineering specification – independent of the control limit of a process.
