Celonis PQL: A Query Language for Process Mining

Process mining studies data-driven methods to discover, enhance, and monitor business processes by gathering knowledge from event logs recorded by modern IT systems. To gain valuable process insights, it is essential for process mining users to formalize their process questions as executable queries. For this purpose, we present the Celonis Process Query Language (Celonis PQL), which is a domain-specific language tailored toward a special process data model and designed for business users. It translates process-related business questions into queries and executes them on a custom-built query engine. Celonis PQL covers a broad set of more than 150 operators, ranging from process-specific functions to machine learning and mathematical operators. Its syntax is inspired by SQL, but specialized for process-related queries. In addition, we present practical use cases and real-world applications, which demonstrate the expressiveness of the language and how business users can apply it to discover, enhance, and monitor business processes. The maturity and feasibility of Celonis PQL is shown by thousands of users from different industries, who apply it to various process types and huge amounts of event data every day.