Contents
- Index
Min OC Curve - Minimum Operating Characteristic Curve
The minimum OC curve is calculated and displayed only when the protection varies. In this case the probability of acceptance is not constant. Instead it depends on other circumstances such as the quality of previous lots produced. For the ANSI Z1.4 plan shown above, the results of inspections of previous lots determines which of three sampling plans to use on the current lot.
The minimum OC curve shows the minimum probability of acceptance across all possible circumstances. For the ANSI Z1.4 plan this means the minimum probability of acceptance of the three plans that might be used. The minimum OC curve is the bottom of the three OC curves shown above. It along with the maximum OC curve and stationary OC curve describe the range of protection that can result when the protection varies.