A synergy case assumes the combined organisation is the better half of each. In practice it is a third operating model nobody has ever run, and the cost of learning it is the synergy.

The number arrives before the knowledge

The synergy figure is set in the deal model, months before anyone has seen how either company actually decides anything. It is a percentage of a combined cost base, not a design. By the time somebody has to make it real, the number has been repeated in enough rooms to have become a commitment.

Best of both is a third company

Faced with two ways of working, an integration team does the reasonable thing and takes the better half of each. The pricing model from one, the account structure from the other, the planning cycle from the first, the escalation path from the second. Every one of those choices is defensible on its own.

Two organisations that each work, combined into a third that nobody has practised.

The cost shows up as coordination. More meetings to align, more exceptions to arbitrate, more decisions escalated because the rule is new and nobody trusts it yet. That coordination is paid for in exactly the months the synergy was supposed to land, which is why the case slips a year and then gets quietly rebased.

Pick a base, port the exceptions

The alternative is less elegant and much faster. Choose one company’s operating model as the base, in full. Then port only the exceptions from the other that you can name, justify and give an owner. You will keep some things that are worse in the abstract, and you will keep them because a working system people already run beats a better system nobody has run yet.

Choosing the base is a real decision with real losers, which is why it gets avoided and replaced by a workstream. It is also the single choice that most determines whether the case lands.

What a sponsor should ask for

Not an integration plan. A short answer to three questions: which operating model is the base, which exceptions survive and who owns each, and which decisions move on day one. If those cannot be answered inside a month, the synergy number is a forecast and not yet a plan.

This is the kind of question a Design answers, and the kind a Verdict tests when the integration design already exists.

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