In a buy-and-build you stack synergies: procurement advantage across the platform companies, shared overhead, cross-sell between the add-ons. On paper it adds up to an attractive amount. In execution, part of that doesn't land. Not because the model was wrong, but because an assumption didn't hold, an owner was missing, or nobody tracked it until the moment when course-correcting still made sense.
The question "what do you do with a synergy that doesn't land" has no good answer after the fact. The answer lies in how you set up the synergy before you knew whether it would land.
Every synergy in a buy-and-build rests on an assumption that isn't in the Excel sheet. "Shared procurement" presumes that suppliers are willing to consolidate, that contracts are terminable within the plan's timeframe, and that the platform companies actually purchase the same items and not just the same category. If one of those assumptions doesn't hold, the synergy doesn't land, and that is then not an execution problem but a calculation problem you could have foreseen if you had asked which assumption underlies your synergy amount.
With a single acquisition, that is something you figure out once. With a buy-and-build involving multiple add-ons, that question repeats itself per synergy per company, and the assumptions differ per combination. What held for the first add-on need not hold for the third.
A synergy that belongs to no one does not land on its own. In buy-and-build, that risk is greater than with a single deal: the synergy often plays out between two or more add-ons, and none of the local management teams feels responsible for it. The procurement advantage sits between company A and company B; the cross-sell sits between the sales team of C and the customer base of D. Without someone explicitly carrying that, the synergy remains on paper while no one executes it.
The question who owns a synergy is therefore not a formality but the first test of whether a synergy has any chance at all. No owner, no landing — that is almost a law.
If the assumption holds and the owner has been designated, the question remains how you know whether the synergy is on track before it is too late to course-correct. A synergy that only becomes visible as missed at the year-end close was already readable nine months earlier from the progress of the underlying steps. That requires a fixed rhythm, with a status that does not depend on the optimism of whoever is reporting. What that looks like is described at how do you track synergies with traffic lights in a buy-and-build: red, amber, green per synergy, with the substantiation that makes the color correct.
And substantiation is the word it comes down to. A synergy that only exists as an amount in a model has nothing to track against. A synergy with a calculation, a source for that calculation, and a designated owner has a baseline you can measure against. How you build that substantiation before the synergy becomes the starting point of the Day 1 or Day 100 plan is described at how do you substantiate a synergy.
There is a second scenario, separate from execution problems: the synergy was correct at the moment of the deal, but the market or the organization has changed. A supplier has been acquired, a customer has fallen away, the two add-ons turn out to have less overlap than expected upon implementation. Then the question is not how you execute the synergy better, but whether it still belongs to the deal thesis you started with. That thesis disappears from view more often than it gets revised, as described at what is a deal thesis and why does it disappear, and a synergy that no longer fits the thesis is better dropped than kept artificially alive.
That is also where the standing question returns: should this even be combined. Not every synergy that exists on paper deserves to be executed. Sometimes the answer to a synergy that doesn't land is not "pull harder" but "let go, and remove the amount from the plan before it becomes a debt that no one can repay anymore." Testing whether that is the case belongs as standard, not as exception, at how do you test whether a synergy is still feasible.
A synergy baseline, a Day 1 plan and a Day 100 plan that do not contradict each other, and a place where the status of every synergy is visible per owner and per assumption — that is what is needed to answer this question before it becomes urgent. That tooling is under construction with us. Anyone interested can sign up for the waitlist; there is currently no working product to offer, only the structure that will underlie it.
Once you know which synergies stand, who carries them and which assumptions support them, the next question is how much of the associated work — the adding up, the revising, the tracking of status per synergy — actually requires human hours and how much of that can be done by AI. The work scan from FTE TO AI calculates that per task and shows which part of the work can be taken over, so that the integration team keeps what people are truly needed for: the judgment about the assumption, not the maintaining of the overview.
Vraag maar wat er op Day 1 moet staan, of wat integreren juist kapotmaakt.
Answers come from this site’s knowledge base. Not tailored advice, and not a scan of your company.