The Operating Characteristic (OC) Curves utility enables you to construct OC curves for control charts and attribute acceptance sampling plans. OC curves are available for XBar, P, NP, C, and U charts. For specified control charts, the OC curve shows the probability of failing to detect a shift of a particular size. In addition, there are OC curves for single and double attribute acceptance sampling plans. For a specified acceptance sampling plan, the OC curve shows how the probability of accepting a lot changes with the lot quality.
Note: The OC curves for control charts are two-sided curves. They are drawn for negative and positive shifts. Often OC curves display one curve for the absolute shift.
Launch the Operating Characteristic Curves by selecting Analyze > Quality and Process > OC Curves. Select the OC curve of interest and click OK to launch.
Figure 15.4 OC Curves Launch Window