What is post-merger integration?

Post-merger integration (PMI) is the work of merging two companies after the deal closes: aligning systems, data, processes, people, leadership and culture so the combined business runs as one. It is the phase where the value case behind the deal is either realised or lost.

How long does post-merger integration take?

The operational phase usually runs from Day 1 to about 180 days after close. The strategic horizon (full synergy realisation, systems consolidation, data and AI platform convergence) runs from year one to year three. The first 90 days set the direction; the next two years show whether the deal thesis held.

Can you do PMI without a pre-deal assessment?

Yes, but you start with less information. The way in for that case is a short orientation sprint (Bearings in the Passage method): one to three weeks of access, scoring and risk surfacing, after which the integration picks up at the planning stage with the gaps written down. You trade some depth for speed.

Why bring in a PMI lead instead of using internal staff?

Internal leaders still have the business to run. PMI needs dedicated portfolio control, RAID discipline across workstreams, stakeholder engagement at every level, and an outside read of where the integration really is compared with where the SteerCo report says it is. A fractional PMI lead runs it as a managed portfolio while your leaders run the business.

How is PMI work priced?

In Daniel Xuereb's Passage method, the reads (Sound before a deal, Bearings after close) are fixed price. Running the integration and measuring the value (Transit and Harbour) are billed on his fractional day rate, $1,850 + GST a day, pro rata on the hours worked. Where the baseline set during planning can be measured, a base fee plus a share of the synergies realised against it can be agreed instead.

Post-merger integration after close: what to do when nobody ran the pre-deal read

You closed the deal. The board signed off, the announcement went out, and the integration starts on Monday. Nobody ran a structured digital, change and people read before close. That is a common position, and a recoverable one.

What has changed in PMI

Two things are different from a decade ago. More of the synergy case now sits in technology: data platforms, AI capability, customer systems and the IT operating model. And the capability you bought is often three or four people on the target’s engineering team, who can leave in a week.

So integration needs portfolio control, real RAID discipline, an outside view of where things stand, and a value tracker. None of that happens by default.

What breaks in the first 90 days without a pre-deal read

The Day 1 cutover slips. Identity, email, licensing and a handful of customer systems need to work on Day 1. Without a map of the target’s estate, the cutover is rebuilt under time pressure, and something breaks in public.
Key engineers and operators leave. The two or three people who run the platform you bought get recruiter calls within days. If nobody had a retention conversation before close, the capability goes before it is documented.
Data migration estimates blow out. The volume, quality and lineage of the target’s data is often worse than the pitch suggested. You find out in the dry run, and the migration plan was built on the pitch.
Change-of-control fees appear. Software licences, cloud contracts and integrator agreements often carry change-of-control clauses the deal team did not surface, and nobody budgeted for the fees.
Customers ask questions you cannot answer. A regulated client asks where its data will live after the integration. Without a written position, account managers stall, and a contract the value case assumed starts to wobble.

Each of these is recoverable, though seldom in the hour you discover it. The first 90 days need a different plan.

The way in: a one to three week orientation sprint

When there was no pre-deal read, start with a compressed orientation sprint. It rebuilds the position a full pre-deal assessment would have given, accepts lower confidence where it has to, and writes down what is still unknown. In Passage this sprint is called Bearings.

Over one to three weeks:

01Orient. Confirm what the acquirer believes it bought, get access to systems and key people, and map the stakeholders.
02Read. Score the target across the five dimensions, starting with whatever threatens Day 1 and the value case.
03Frame. Write the integration brief, draft the workstreams and agree the governance to stand up.

The output is the Bearings Brief, a shorter version of the Risk and Readiness Profile a pre-deal read would have produced. It is enough to plan against, it says plainly what it does not know, and it gives the integration a written baseline to measure everything else against.

What running PMI properly looks like

Five disciplines, each of which can start in the first month:

An Integration Management Office (IMO). One point of control with named decision rights, a cadence that steps down over time (weekly at first, then monthly, then quarterly), and a sponsor who owns the value thesis.
Workstream charters and owners. Each digital, change and people stream has a written charter, a named owner, a Day 1 design and 30, 60 and 100 day milestones.
A RAID and dependency map across workstreams. Most tools track risk inside each workstream. The risks that hurt usually sit between them.
A value tracker tied to the baseline. Every benefit in the deal case becomes a line with a baseline, a target, a horizon and the number realised so far. Reporting outcomes starts in week one.
One source of truth, read at four levels. The board reads a one-page summary, the IMO lead the portfolio view, workstream owners the playbooks and the people doing the work the checklists. All four read the same live data.

The five dimensions and the twelve domains

Scoring an integration needs a fixed rubric. Passage uses five dimensions, scored the same way at every stage:

Digital and technology. Systems, data, AI, architecture, cyber security and technical debt.
Change. How much is changing, communications, adoption and ways of working.
People. Key-person risk, capability, culture and retention.
Readiness. The ability to operate, absorb the change, sustain it and go live.
Value and outcomes. What the integration must deliver, and how that is measured.

Within digital and technology, twelve domains are each assessed or marked not applicable, so the same rubric works for a small bolt-on and a multi-entity merger:

Applications and ERP
Data and analytics
AI and automation
Infrastructure and cloud
Cyber security
Integration and middleware
Networks and end-user computing
Digital products and customer
Licensing and vendor contracts
IT operating model
Technical debt
Compliance and sovereignty

AI and automation is a domain in its own right because in a modern deal it can be both a source of value and a source of risk. It is also checked inside every other domain.

How I price PMI work

I run a digital PMO as acting Head of Digital Project Management, and M&A integration is part of that work. For other companies, the pricing follows the shape of each stage.

The read is a fixed price. Bearings after close, or Sound before a deal, is a defined output at a fixed fee. The read is yours whatever you decide next.
Running the integration is on the day rate. Transit (running the integration) and Harbour (measuring the value) are billed at my fractional rate, $1,850 + GST a day, pro rata on the hours I put in. Invoiced fortnightly in arrears on fourteen-day payment terms, with an hours breakdown on every invoice.
A share of synergies, by agreement. Where the baseline set during planning can be measured, we can instead agree a base fee plus a share of the synergies realised against it.

Exact fees are set for each deal, and you have them in writing before you commit to anything.

What changes for an Australian deal

For an acquirer in Australia, the extra threads are sovereignty (where data lives and where AI workloads run), regulatory load (APRA, the OAIC and the Privacy Act 1988) and the local talent market. They do not change the method. They change which domains carry the most weight in the read and the order of the recovery work.

Recovering from a missing read

An integration can recover from a missing pre-deal read. It needs portfolio control, a written baseline and a value tracker from the first month, and a one to three week orientation sprint is how you get a position to plan against. If you are looking at a closed deal and working out who to bring in, the Passage page has the full method, and the section below has my terms.