About PPB and PPMs (Process Performance Baselines and Process Performance Models)

Important to process improvement frameworks (such as CMMI) and to most modern organizations is the ability to measure and detect deviations to common well known (official) process performance baselines (PPB).
Better yet is the capability of "predicting the future" i.e. the behavior of  the process, having as inputs some well known data, supported by the process performance model (PPM).

CMMI-DEV OPP Process Area is intimately related with these concepts (PPB and PPMs) and need them in place for the organizations and its software development process(es) to be be certified.

One example of a process performance model is the COCOMO model, which aims to estimate project cost having as inputs some of the project characteristics:
https://en.wikipedia.org/wiki/COCOMO