Post-merger integrations often stall on the organisation that has to deliver the synergy case: leaders who leave or disengage, decisions without a clear owner across the two companies, and new handoffs between teams that have not worked together before. A meta-analysis of acquisition research found executive turnover and the level of integration to be the most significant of the factors it examined.
What does a synergy case assume about the organisation?
That the combined organisation will make the decisions and handoffs the case depends on, at the pace the case assumes. Revenue synergies need two sales teams to share accounts. Cost synergies need someone to decide which system, site or team is kept. Each is an organisational event with an owner, a sequence and a risk.
The financial model is usually thorough on the value and thin on who delivers it. A useful check is to take each major synergy line and ask three questions: whose decision is it, which two teams have to work together for it to land, and what happens to the people whose roles it changes. Where the model cannot answer, the organisation is being assumed.
Why does leadership turnover matter so much after an acquisition?
Because acquired-firm leaders often carry the knowledge, relationships and informal authority the integration relies on. Bilgili and colleagues' meta-analysis found executive turnover among the most significant factors in post-acquisition performance, and that CEO and top-team turnover have opposite effects, so what matters is which leaders leave.
The practical consequence is to identify, before closing, which leaders the integration plan depends on and why. Some departures clear the way for a new direction. Others remove the person who knows how a key customer relationship or process actually works. The two look the same on a retention list.
Who owns the decisions during an integration?
Often it is unclear, and that is a frequent early source of delay. Two leadership teams, two sets of habits and a new governance layer can leave the same decision with several owners or with none. Naming the owner of each integration-critical decision before day one prevents weeks of informal negotiation.
The first hundred days tend to concentrate these calls: which brand, which system, which structure, which leader. A short decision register, with the owner, the people consulted and the date each call is due, does more for pace than another steering committee. It also makes visible where an acquired leader has lost authority they are still expected to use.
Where do integrations break down day to day?
At the new interfaces between teams from the two companies. People in each organisation know how to get things done in their own system. The integration asks them to rely on colleagues they do not know, through processes that are still being designed. That is where commitments slip.
Research on strategy execution shows how fragile cross-unit commitments are even inside one company: in Sull, Homkes and Sull's work, only 9% of managers could rely on colleagues in other units all the time. An integration multiplies those interfaces and removes the shared history that makes them work. Mapping the handoffs the synergy case relies on, and giving each an owner, is the most direct way to protect them.
What should be assessed before the deal closes?
The leaders the value creation plan depends on, read against what the plan will ask of them, and the decisions and handoffs the synergy case assumes. People due diligence brings this into the deal process, so the investment committee sees organisational risk alongside the commercial and financial work.
Done before closing, this changes the integration plan while it is still cheap to change: the sequence of decisions, the retention of specific people, the design of the first interfaces. Done after, it becomes a description of problems the organisation is already absorbing.
Where this stops
This note covers the organisational side of an integration. It does not assess the strategic logic of the deal, the valuation, or the commercial assumptions behind the synergy case, and a well-prepared organisation cannot rescue a deal whose economics do not hold. The meta-analysis cited here pools studies of many kinds of acquisitions, so its findings describe tendencies rather than the outcome of any single deal.
How Atlas reads it
Atlas treats a change of ownership as one of the six moments that should prompt a forecast of the organisation behind the plan. Before closing, People Due Diligence reads the leaders the value creation plan depends on against what the plan will ask of them. After closing, the reading covers the combined organisation: who owns the integration decisions, which new handoffs the synergy case relies on, and where demand rises fastest.
Each judgement carries the evidence for it and what argues against it, a confidence level and an owner. The ratings describe the arrangement around each leader, and the recommendation starts with the cheapest effective change, such as reassigning a decision or resequencing the integration, before any question about the person.
Sources
- T. V. Bilgili, C. J. Calderon, D. G. Allen and B. L. Kedia, Gone With the Wind: A Meta-Analytic Review of Executive Turnover, Its Antecedents, and Postacquisition Performance, Journal of Management (2017)
- T. V. Bilgili and colleagues, Gone With the Wind, Journal of Management (2017)
- Donald Sull, Rebecca Homkes and Charles Sull, Why Strategy Execution Unravels and What to Do About It, Harvard Business Review (2015)
Questions
Research points to the organisation as much as the economics. A meta-analysis of 112 studies found executive turnover and the level of integration among the most significant factors in post-acquisition performance. Unclear decision ownership and new handoffs between teams from both companies are where the synergy case most often loses pace.
It depends on what the integration plan needs from them. CEO and top-team turnover affect performance in opposite directions in the research, so a blanket retention policy is a poor guide. Identify which leaders hold the knowledge and relationships the plan relies on, and focus retention there.
It is the assessment, before closing, of where the leaders and organisation a deal depends on are likely to strain against the value creation plan. It sits alongside financial and commercial diligence and gives the investment committee a view of organisational risk while the integration plan can still be changed cheaply.
The integration-critical decisions should get named owners and due dates, the leaders the plan depends on should know their roles, and the handoffs the synergy case relies on should be mapped and owned. Pace in the first hundred days depends heavily on clear decision rights.
Look for repeated escalation of the same decisions, synergy milestones slipping at the same handoff, and acquired leaders who are consulted less than their role implies. These signals usually appear before the synergy numbers move, and they point to where ownership or interfaces need attention.