Key event 2 · The how
Week One: three days that turn a plan into the teams’ own
In short
Week One is the second key event in an integration. In three days, one mixed team per workstream, with members from the acquirer and the acquired company, takes a pre-prepared plan with a charter and draft key projects, challenges, changes and completes it within guardrails, including a list of what it will not do. On day three, all teams resolve their interdependencies together. The result: a plan the teams own and can be held to, within days, not weeks.
What Week One is
Week One answers the how. It takes place at the start of the integration, right after Day One, and it lasts three days. Every workstream (IT, HR, finance, operations, procurement, sales, marketing, legal, R&D and whatever your deal needs) gets one team with members from both companies.
The teams do not start from a blank page. Each one receives a prepared integration plan: a charter and draft key projects, built from the due diligence and from Executive Alignment. Their job is to challenge it, change it and complete it.
Why the teams write the plan themselves
A plan handed down from a project office gets compliance at best. A plan the teams have shaped gets commitment. That is the shift from “Why is this happening to me?” to “How can I help?”.
Mixed teams also do something no workshop slide can: people from both companies solve real problems together in the first week. They learn how the other side thinks, where the knowledge sits and whom they can trust. Leaders become architects of the integration, not recipients of it.
The three days
| Day | What happens |
|---|---|
| Day 1 | The why from Executive Alignment, the guardrails and the prepared drafts. Teams start work on their charter and key projects. |
| Day 2 | Each team challenges, changes and completes its charter and key projects, and writes its list of what it will not do. |
| Day 3 | Every team hears the others’ plans; interdependencies are resolved together. Owners are confirmed, lighthouse projects selected, next steps agreed. |
Guardrails make speed possible
Week One is fast because the frame is clear. Guardrails come from Executive Alignment: the deal rationale, the integration principles, the KPIs and the decisions that are already taken. Within that frame, teams have real freedom. Outside it, they escalate rather than reopen.
The not-to-do list is one of the most valuable outputs. Every team states what it will deliberately leave alone, at least for now. That protects people from overload and keeps the integration from spreading into everything.
Day three: one company, not nine plans
Workstreams depend on each other. IT needs HR’s organisation design, sales needs the product decisions, finance needs everyone’s numbers. On the third day, every team presents its plan to all the others. Interdependencies surface in the room and are resolved there, instead of in weeks of email.
This is often the first time people experience the combined company working as one.
The outputs
- A charter per workstream that the team wrote itself.
- Key projects with owners on both sides.
- Not-to-do lists and resolved interdependencies.
- Lighthouse projects that show early, visible progress.
From the following week, the teams report in the weekly cadence, and four to six weeks after closing the Synergy Working Session sets the priorities.
Result: a plan the teams own and can be held to, within days, not weeks.
Questions leaders ask about Week One
How long does Week One take?
Three days, at the start of the integration, right after Day One. Day one sets the frame, day two completes the charters and not-to-do lists, and day three resolves the interdependencies between all workstreams.
Who takes part in Week One?
One mixed team per workstream, with members from both the acquirer and the acquired company, typically the people who will lead the work in that area. Managers of the acquired company should sit in the teams, not just receive the results.
Is it too late for Week One if the integration has already started?
No. A compact Week One works at any point, especially with workstreams that are stuck. The same principle applies: a prepared draft, clear guardrails and a team from both sides that makes the plan its own.