Why Your M&A Integration Should Start During Diligence
By Chintan Dhanji, Managing Director, SC Strategy Consulting
The most expensive mistake in M&A isn't overpaying for the target. It's losing value between the day the deal closes and the day the integration delivers.
I've led both sides of this - diligence and integration - on the same deal. A ~$300M acquisition for a Fortune 500 healthcare company subsidiary. The result was approximately $100M in revenue synergies. And the single biggest reason it worked was that we started integration planning before the ink was dry.
The Handoff Problem
In most acquisitions, there's a clean break between two phases. The diligence team does their work - financial analysis, risk assessment, synergy estimation. They produce a report. Then a separate integration team picks it up and tries to turn those estimated synergies into reality.
That handoff is where value gets destroyed.
The diligence team understands the target intimately. They've spent weeks or months inside the financials, talking to leadership, mapping operations. They know where the risks are, where the opportunities are, and what the numbers actually mean in context.
The integration team inherits a document. They have to rebuild all of that understanding from scratch - often under pressure to show results quickly. By the time they're up to speed, momentum has been lost, key people have left, and the synergies that looked compelling in a spreadsheet have started to evaporate.
What Starting Early Looks Like
On the healthcare acquisition, we ran diligence and integration planning in parallel. While the diligence team was assessing risks and modeling the deal, we were already asking integration questions:
These questions informed the diligence work, and the diligence work informed the integration plan. Instead of two sequential processes, we had one continuous flow of intelligence.
The Day 1/100 Framework
We built the integration around two milestones: Day 1 and Day 100.
Day 1 is about stability. The deal closes, and suddenly two organizations need to function as one - or at least not break anything. Day 1 planning covers:The 100-day window isn't arbitrary. It's the period where organizational energy for change is highest. People expect disruption after an acquisition. They're willing to adapt. After 100 days, that window closes, and resistance to change increases dramatically.
Cross-Functional Discipline
Integration isn't a strategy exercise. It's a project management exercise - one of the most complex a company can undertake.
On this deal, we had workstream leads from every function: operations, technology, legal, HR, finance, sales, and customer success. Each workstream had a clear mandate, specific milestones, and weekly check-ins.
The weekly cadence was non-negotiable. Every workstream lead reported progress, flagged blockers, and escalated decisions. Leadership reviewed the consolidated status weekly and made real-time decisions to unblock issues.
This sounds basic. In practice, most integrations don't have this discipline. Workstreams operate in silos, leadership gets quarterly updates instead of weekly, and by the time a problem surfaces it's already cost millions.
Finding Synergies Others Miss
The ~$100M in revenue synergies didn't come from obvious cost cuts. It came from cross-product opportunities that only became visible when you understood both organizations deeply.
During diligence, we mapped the product portfolios of both companies and identified where the target's offerings could be sold to the acquirer's customer base, and vice versa. These cross-selling opportunities were significant - but they required coordinated sales efforts, updated pricing, and in some cases, product bundling that hadn't existed before.
We also identified operational synergies: shared infrastructure, consolidated vendor relationships, and process standardization that reduced costs without reducing capability.
The financial model we built for negotiations wasn't static. We updated it continuously as new information emerged during diligence - adjusting synergy estimates up or down as we gained clarity on what was actually achievable. This gave leadership a real-time view of deal value, not a snapshot from week one.
The People Factor
The most fragile element of any acquisition is talent. Key employees at the target company are uncertain about their futures. They're getting calls from recruiters. They're watching to see whether the acquiring company respects their culture and expertise, or treats them as redundant.
We identified critical talent during diligence - not after close. We built retention plans before Day 1. And we ensured that communication to the target's employees was honest, timely, and specific about what would change and what wouldn't.
The companies that lose key talent during integration are usually the ones that waited too long to have these conversations.
The Lesson
M&A integration isn't a post-close activity. It's a pre-close discipline.
The companies that capture the full value of their acquisitions are the ones that treat diligence and integration as a single continuous process. They staff them with overlapping teams. They build the integration plan while they're still learning the business. And they execute with the kind of weekly operational discipline that most organizations reserve for their biggest product launches.
The $100M in synergies from that healthcare acquisition wasn't luck. It was the result of starting early, planning rigorously, and executing with discipline through the first 100 days.
If you're planning an acquisition and your integration team hasn't started yet, you're already behind.