A project assembles resources (people, tools, and facilities) for a finite time to produce and deliver products (and services) using a process. A production process is the “software” that humans “execute” during a project. The process consumes resources, and so affects project costs and duration. The process also affects product cost, performance, and quality. Thus, being able to measure, predict, and control process performance can be vitally important to any organization. This chapter describes the challenges and identifies possible approaches. This is still an area of active research so the models are primarily experimental and have limited practical utility.