Phenomenon-driven research (PDR) establishes when a phenomenon warrants investigation but offers little structured guidance on diagnosing why a state change occurred or which aspect of the phenomenon drove it. We address this by introducing a framework based on the Belief-Action-Outcome (BAO) framework and meme theory, positioned after a state change is detected but before full-scale theorising begins. By separating institutional beliefs, concrete interventions, and realised and unrealised outcomes into distinct analytical layers, the framework allows researchers to identify which aspect of a phenomenon produced the change and why. We demonstrate its usefulness through the Maritime Single Window (MSW), a digital platform mandated across EU Member States, where the replacement of Directive 2010/65/EU by Regulation (EU) 2019/1239 represents such a state change. Our contribution equips IS researchers with an analytical structure that helps bridge the gap between rigour and relevance.