Process Mining analyzes event logs from business processes to enhance understanding, verification, and improvement of these processes. Event logs typically originate from multiple sources and require extensive preprocessing before applying process mining techniques. This preprocessing includes filtering, composing, joining events into traces, and fixing or calculating attribute values. Existing process mining tools offer ad-hoc manual actions through graphical interfaces and simple domain-specific languages, but these methods have limitations, and there is no standardized approach for processing event logs.

The primary contribution of this work is the Process Query Language (PQL), a domain-specific language (DSL) for processing event logs that surpasses current techniques. We begin by analyzing several existing DSLs concerning key success factors, followed by an evaluation of current business process DSLs to identify their limitations. Based on this analysis, we propose the PQL specification as a draft technical standard. PQL's design decisions are validated through an interpreter implementation and its application to numerous use cases.