Engineering and Economics Concepts for Understanding Software Process Performance This chapter presents the engineering (and management) perspective of a production process. From anengineering perspective, a production process is more complex, and must also include a monitoring and control process. The chapter outlines some simple quantitative models of processes. It introduces some quantitative models using economics concepts, such as fixed/variable costs and economies/diseconomies of scale. The chapter discusses some characteristics of softwareengineering datasets and their data distribution. It also discusses the different types of data distribution observed in the datasets documented in the software engineering literature, as well as in the datasets available in public domain repositories. The chapter highlights the explicit and implicit variables in productivity models. Most of the variables that are significantly different in the datasets of projects from multiple organizations were, in practice, fixed in this development environment. The chapter also presents the possibility of multiple economic models within the same dataset.