How do organizations refine their post‐merger integration routines over consecutive acquisitions?

The post‐merger integration (PMI) phase of mergers and acquisitions (M&A) can determine M&A success. Little is known about how organizations refine their PMI routines with accumulated M&A experience. This study proposes a process model of PMI‐routine development, where the outcomes of routines enacted in earlier acquisitions shape routines in subsequent acquisitions. We test the model using 312 instances of routine implementation, across five consecutive acquisitions by the same acquiring company, and make two key scholarly contributions. First, we advance prior research by identifying how a routine's level of complexity moderates the association between routine adherence and routine outcomes. Second, we elucidate the effect of learning from failure—uncovering a learning process with performance feedback as input. Specifically, negative routine outcomes at the focal acquisition strengthened the positive effect of the improvisation (low adherence) enacted in the focal acquisition on the subsequent modifications to the codified routine, which are likely to improve its performance in future acquisitions.