Post-merger integration support

An acquisition does not end at closing

Signing is the beginning, not the end. That is the moment deal value starts to materialise or to disperse — and what settles it is not the financial model but what happens to people, processes and decisions immediately after the announcement.

The most common reason that value disperses is not financial; it is human and cultural. Key people from the acquired company leave before anyone has had the conversation with them about their place in the new structure. The management styles of the incoming and the incumbent leadership collide without resolution. Back-office harmonisation slips from quarter to quarter because nobody owns it. The result tends to look the same: an organisation that, long after the transaction has formally closed, still runs as parallel structures under a single brand.

The order of repair is not optional. First the stabilisation of people and back-office processes, and only then the integration of customer-facing operations and of culture. The reverse order produces cultural declarations with no operational backing — and that pattern repeats regardless of the industry.

Four phases and the decision points

Phase 0 — due diligence and preparation. An audit of the organisation, the culture and the key roles, an integration risk map, the identification of quick wins, and an initial integration model. This is also where we define the programme-wide measures and configure the team. The output of the phase is a go/no-go decision and a baseline plan.

Phase 1 — the first 100-day plan. Stabilising key talent, standing up the PMO, an internal communication plan with a separate narrative for each level of the organisation, a map of people decisions and an integration schedule. The output is people retained and operational control regained.

A gate review between phase 1 and phase 2. A board and integration committee session that verifies the stabilisation goals and decides on entering full operational integration. This is a distinct item in the programme, not a formality: the absence of that decision is the most common reason accountability dissolves in the phase that follows. A second gate review closes operational integration and verifies HR systems integration and the culture goals. A third closes the programme and hands accountability to the line structures of the combined organisation.

Phase 2 — operational integration. Rollout of the target operating model, process harmonisation, HR systems integration, the culture transformation programme, and capability development with onboarding. The output is one integrated organisation.

Phase 3 — stabilisation and optimisation. Process optimisation, measurement of effectiveness and culture, talent retention, better performance management, and closing the PMO. The output is the full deal value accounted for against the plan.

The phase boundaries are not rigid — they are adjusted to the scale of the transaction, the complexity of systems integration and the readiness of the acquiring organisation. The last two phases are conditional in scope: what settles them is the gate review, not an offer.

Ten areas of support

Operating model and governance. Designing and rolling out the target operating model of the combined organisation: the process map, functional versus business structure, the decision model, the rules of centralisation, the shared services model. Alongside it, building and running the programme PMO together with integration portfolio management and board reporting. And the standards of corporate governance, compliance, data security and business continuity during the transition — a critical area when the two entities operate under different regulatory regimes.

People and culture. Running the change programme from diagnosis, through the rollout plan and communication at every level, to the measurement of adoption. An HR strategy derived from the business goals of the combined organisation: harmonising HR policies, pay and benefits, appraisal models and job classification, as well as mapping teams, identifying the key roles and planning their retention. Culture transformation: diagnosing the cultures of both organisations, defining the target behaviours, a rollout programme measured on adoption, and the facilitation of leadership integration sessions. Capability, talent and onboarding — during integration, development programmes bind the teams from both organisations around shared standards rather than only developing individuals.

Processes and systems. Mapping, harmonising and optimising processes, centralising back-office work in a shared services model, and building a continuous improvement rhythm. This is the area where deal value materialises fastest, because removing process duplication produces a measurable effect within the first months. Next to it sit the HR systems: requirements definition, running the rollout and integrating the modules that carry onboarding, performance management and development. HR systems integration that misses its date blocks the harmonisation of pay, appraisals and talent development — which is why we treat it as the milestone of the operational integration phase, with a decision point before moving on.

Filling leadership gaps. Taking a key role on an interim basis for the duration of the transition. This form is particularly valuable in three situations: when the acquired organisation loses key people right after the announcement, when filling the target roles is delayed, or when an interim role is held deliberately until the new structure settles. It keeps operational and programme continuity without interrupting the integration cycle.

Measures and board reporting

We define the measures in phase 0, before the programme starts, in four layers.

The stabilisation layer belongs to the first hundred days: retention of key talent at the level agreed with the board in phase 0, continuity of customer service on the back-office side, and how far the PMO and the communication plan are in place. The operational integration layer looks at the share of harmonised end-to-end processes, the rollout of integrated HR systems, culture adoption surveyed on an agreed cycle, and the reduction of process duplication. The deal value layer accounts for cost and revenue synergy against the plan and the time it takes the integration to reach break-even. The stabilisation layer of the combined organisation measures employee engagement, customer satisfaction, time to full productivity for new joiners, and attrition in the first year.

Reporting runs on three cycles. The monthly status report carries the assessment of each workstream, the main risks and the decisions that need the board. The quarterly value report accounts for realised synergy against the plan and corrects the forecast. A strategic report every six months speaks to the effect of the integration on market position. The PMO maintains a dashboard available live to the board and the integration committee, with alerts on risks that cross the agreed thresholds.

Forms of engagement

There are four, and they combine — over time and across areas, with movement between an advisory and a delivery role as the programme matures.

Interim management means taking a key role during the transition with full operational accountability and reporting to the board. Project consulting means designing and running one specific workstream: culture transformation, the competency model, HR harmonisation, process optimisation or an HR systems rollout. Facilitation covers moderating board and integration committee sessions, integration workshops for the leadership team, and risk anticipation sessions. The fourth form is running the PMO together with reporting status, risks and deal value.

The level of involvement ranges from a few days a month in an advisory and facilitation role to a full-time commitment in interim management and PMO delivery. We agree the configuration after phase 0, together with the scope.

A boundary worth knowing

Four areas stay outside the scope, and that boundary is deliberate — a full integration cycle at scale needs several specialist partners with accountability clearly divided. We do not run the legal and tax structuring of the transaction. We do not run audit due diligence in its accounting, tax and legal layers. We do not run ERP migration or integration beyond the HR modules. We do not design cyber security architecture and we do not run security testing. In those areas we coordinate the work from the business and people side; we are not the technical delivery partner.

The boundary also runs the other way, and it is worth naming, because the two services are easy to confuse. If there is no acquisition and the problem is the quality of collaboration itself — who informs whom, whose decision it is, why processes stretch out — then the right engagement is not an integration programme but an organisational culture assessment: a diagnosis of collaboration mechanisms with a change design, without running a whole integration cycle. A culture diagnosis can be one workstream inside an integration programme, but it does not replace running the programme.

Post-merger integration support is a consulting service, not a training course. It has no syllabus, no level and no open enrolment date — it has a cycle of phases with decision points, success measures, and one owner of accountability to the board. If what you need is to build competencies in a workshop format, the trainings linked from this page are the right path.

Let’s talk about where your transaction stands — that decides whether we start at phase 0 or from catching up.