Most integration plans fail before they're even written — not because the team lacks effort, but because the "plan" is really just a task list with deadlines attached. A real post-merger integration plan does something different: it ties every workstream back to the reason the deal was done in the first place.

Below is the structure Stonehill uses when building integration plans for private equity firms and corporate acquirers. It's organized around five workstreams, each with the components a strong plan needs and an example of what good looks like in practice. If you're looking for a day-by-day breakdown of the first 100 days, see our post-merger integration checklist. This page is the plan itself — the document you'd actually build and hand to your integration team.

1. Integration Strategy & Value Capture

This is the section most plans get wrong by skipping it entirely and jumping straight to task lists.

What it should include:

• The deal thesis, written in plain language — where is the value supposed to come from?

• A synergy register: every cost and revenue synergy identified during diligence, with an assigned owner and target date

• A baseline for measuring progress against the original deal model

Example: A packaging company acquiring a regional competitor identifies $4M in procurement synergies during diligence. The plan assigns a named owner, sets a 90-day target to renegotiate the top five overlapping supplier contracts, and tracks realized savings monthly against that $4M baseline — not as a one-time line item, but as a living number leadership reviews every month.

2. Operating Model & Organizational Alignment

A plan needs to say, explicitly, who runs what.

What it should include:

• A target org chart for the combined entity, not just the acquirer's existing structure with new names slotted in

• Clarity on which leaders, from both organizations, own which functions

• A governance model: who makes which decisions, and how disputes get escalated

Example: When two companies with different finance leaders merge, the plan should name one CFO for the combined entity by Day 1 — even if the final org design is still being finalized — rather than leaving both finance teams reporting separately for months while waiting for a "perfect" structure.

3. Operational & Systems Integration

This is the workstream most likely to blow through timelines if it isn't scoped early.

What it should include:

• An inventory of overlapping or conflicting systems (ERP, CRM, payroll, reporting tools)

• A sequencing plan — what integrates immediately, what runs in parallel temporarily, and what's deliberately kept separate

• Data migration and reporting requirements, so leadership has visibility into the combined business from Day 1

Example: Two companies running different ERP systems don't need to consolidate platforms in month one. A workable plan might keep both systems running in parallel for 90 days while a unified reporting layer is built on top, giving leadership a single source of truth without forcing a risky, rushed migration.

4. Leadership & Cultural Integration

The workstream most plans treat as a soft afterthought — and the one most likely to determine whether the deal actually works.

What it should include:

• Communication Plan: Defines what gets communicated to employees, customers, and partners — and when

• Talent retention list: Identifies the people whose departure would meaningfully damage the business, with retention actions for each

• Culture mapping: Surfaces real differences in decision-making style and pace between the two organizations

• Leadership alignment cadence: Sets a regular forum for combined leadership to work through friction before it becomes attrition

Example: A retention list isn't just names and titles. A strong plan notes why each person matters — institutional knowledge, key client relationships, technical expertise — and what specifically would make them stay through the first year.

5. Integration Management & Execution

The workstream that holds the other four together.

What it should include:

• A standing Integration Management Office (IMO) with clear authority to make cross-functional calls

• A reporting cadence — weekly workstream updates rolling into a leadership-level summary

• A single tracker covering milestones, owners, and status across every workstream, so nothing depends on memory or informal updates

Example: Instead of five separate teams reporting status in five separate formats, the IMO consolidates everything into one weekly dashboard. Leadership sees, at a glance, which workstreams are on track and which need attention — without chasing down five people for five answers.

Turning This Template Into a Working Plan

A template only becomes a plan once it's specific: named owners, real dates, and synergy figures tied to the actual deal model — not placeholders.

That's the part most internal teams struggle with, not because they lack the framework, but because they're also running the business at the same time. Stonehill builds and runs integration plans like this one for private equity firms and corporate acquirers who need the work done with discipline, not just documented.

See how the first 100 days play out in practice with our post-merger integration checklist, or talk to our team about building an integration plan for your deal.