John Gabarro of the Harvard Business School discovered that almost all senior executives, upon entering a new role, experience an iterative  process of progressive learning which  he described as "the three wave phenomena" (shown in Figure 1). Rather than a nice, neat, linear progression of entering the new role by first diagnosing the presenting business problems, creating an action plan, and thenimplementing the action plan to solve the presenting business problems in short order, what Gabarro discovered in his 3 year longitudinal study of more than 30 executives¹ was that the typical executive actually experienced cycles of learning that resulted in three waves of change. The learning was iterative.  There were no short cuts. It did not matter if the new executive was an outside hire or promoted from within. It also did not matter if the situation required a turnaround or not. While each situation had its own unique twists and nuances, the overall model of the executive needing to manage three waves of change was a consistent finding. At this level of management, the essential patterns of executive transitions are a predictable executive learning process far beyond the first 90 to 100 days.

The "Three Wave Phenomena" occurs because the Wave 1 changes (first 3 to 6 months) are often incomplete solutions to the presenting problems, the changes reveal other previously hidden problems, and the changes unintentionally create new problems. The "Immersion" stage that follows allows the executive and his or her teams, in collaboration with other stakeholders, to diagnose the new and existing underlying root causes of the barriers to solving the problems and improving the business' performance.  With most of the diagnoses complete (some level of diagnosis and monitoring is, however, continuous), plans are made to shape the necessary organizational capabilities that will drive improved performance.

Wave 2 typically has the largest number of implemented changes (Wave 1 typically has slightly fewer changes than Wave 2) and requires the effective management of change that will often stretch across departmental and other organizational boundaries. Creating sustainable change also ultimately requires enabling the ownership of the targeted changes by local stakeholders deep in the organizational structure who will ultimately be affected by the changes.. Wave 2 requires a specific set of effective change management skills to successfully implement a critical mass of the changes. That skill set is briefly described later in this article.

Wave 3, Consolidation, includes the smallest number of changes of the three waves. Wave 3 includes continued roll out of the changes of Waves 1 and 2 to the rest of the organization and the associated multiple alignment actions of incentives, monitoring processes, metrics, and accountabilities. Wave 3 changes are intended to institutionalize the primary set of changes from Waves 1 and 2. 

The Refinement stage is essentially a smaller set of efforts focused on continuous improvement of the institutionalized processes.