Process Mining (PM) technology enables organisations to visualise and analyse their business processes. While most research focuses on technical advancements of PM functionality, there is a need for research to focus on how to implement and monitor PM initiatives effectively. This paper introduces the Holistic PM Maturity Model (HP3M), designed to assess and improve PM adoption. Developed using the Design Science Research paradigm through literature review, expert interviews, and multi-method evaluation. HP3M evolved from an initial alpha-version to an enhanced beta-version validated via expert panels and an industrial case study. Unlike previous models, HP3M offers a general framework that redefines PM's technology dimensions in line with emerging AI-infused approaches.