Auditor Directing a PPM

We are trying for CMMI ML 5 Ver 1.2, and our auditor has asked us to come up with a PPM for predicting the outcome of CAR and OID. Can you help me on how to go about it?

When you say auditor, I assume that you mean your Lead Appraiser (LA) is asking you for a PPM for predicting the outcome of Causal Analysis and Resolution (CAR) and Organizational Innovation and Deployment (OID). Is your Lead Appraiser an SEI-certified High Maturity Lead Appraiser? Has your organization identified the need for a Process Performance Model (PPM) to predict the CAR and OID outcomes, or is this solely a request from your LA? Your LA is not the person to tell you which PPMs you need. Do you have Process and Product Quality Objectives (QPPOs) that require PPM(s) to predict CAR and OID outcomes? If the answer is no, then you don't need a PPM for CAR and OID.

What I find odd is that you do not mention a Process Performance Baseline (PPB) for CAR and OID. If you are going to define and develop a PPM, then you really need to develop the CAR and OID PPBs first before you can determine the PPMs. From your brief description, it sounds like your Lead Appraiser may have overstepped his boundaries in asking for the CAR and OID PPM.