Many (if not most) of us have only an intuitive but vague idea of what is meant by a process performance indicator (PPI). This paper is one of the few I have encountered that attempts, successfully, to provide a useful and rigorous specification of a PPI.

This specification (a meta-model) is given in the form of a thorough and well-explained unified modeling language (UML) model. Sufficient examples allow even readers with an imprecise understanding of UML to easily follow the central ideas (and the rest of the paper as well).

In addition, the authors capitalize on the formal PPI meta-model to provide a formal specification for analyzing PPIs and their properties. This analysis addresses questions such as: What business process elements, such as flow or data elements, are measured by a particular PPI? Which business process elements are involved in measuring a PPI? In this process, the authors rely heavily on description logic (DL), although the essential ideas are also accessible to readers unfamiliar with DL.

Finally, the authors convincingly demonstrate a software implementation of their theoretical concepts based on the graphical process editor Oryx and the business process execution engine Activiti. Twenty percent of the paper is dedicated to the application of the model and this software tool to a real scenario involving a change management approval process.

The authors openly admit that the meta-model is still incomplete (for example, when it comes to measuring PPIs related to human resources issues such as workloads). Despite this, I am confident that we will see these concepts evolve into a truly comprehensive PPI notation and tool.