Organization and post-merger integration
Designing how a company is organized (spans and layers, operating model) and bringing two companies together after a merger (integration office, synergy tracking, people).
Key takeaways
- Structure should follow the work: size spans and layers against the type of work, and in a merger track each synergy against plan with an owner, while keeping the people who make the business run.
- For structure, measure spans and layers against the type of work and size the change realistically.
- Organization and integration questions often follow cost or M&A cases.
- The strong answer finds the source of the gap and targets it. The weak one spreads effort where it is not needed.
- Why a generic structure scores lower: Asking every team to cut the same percentage, or to try harder, ignores the type of work and the workstream that explains the gap.
What this case type is and when it shows up
Organization cases ask how a company should be structured: how many managers, how many levels, which decisions sit where, and how teams work together. Post-merger integration (PMI) cases ask how to bring two companies together after a deal and deliver the promised synergies. Both often appear as a follow-up to cost or M&A cases, and both need attention to people as well as numbers.
Key idea
Structure should follow the work: size spans and layers against the type of work, and in a merger track each synergy against plan with an owner, while keeping the people who make the business run.
The underlying theory, in plain language
Span of control is the number of people who report directly to a manager. Layers are the number of management levels from the top to the front line. Too-narrow spans and too many layers slow decisions and raise cost. The right span depends on the work: routine, similar work can support wide spans (often 8 to 12), while complex specialist work needs narrower spans (often 4 to 7).
An operating model describes how the company delivers its strategy: structure (by function, product, region, or a mix), processes, decision rights (who decides what), people and skills, and technology. Change it when the strategy changes, not because a new structure is fashionable.
After a merger, an integration management office (IMO) coordinates the work: it sets the plan, tracks each synergy against its baseline and target, controls one-time costs, and escalates delays. Synergy tracking needs a baseline, a target by year, an owner for each initiative, and the one-time cost to achieve it. Day 1 priorities are to keep the business running, keep customers, and keep key people.
People decide whether integrations work. Key staff often leave after a deal, so retention plans for critical people, clear and early communication, and attention to culture (how decisions are made, how people work) are part of the plan, not extras.
What the prompts sound like, from simple to hard
- Simple: does a UK retailer's head office have too many managers.
- Medium: two Gulf logistics companies merged; synergies are behind plan. What should the integration office do.
- Hard: redesign the operating model of an Indian conglomerate moving from country-led to product-led.
Build the structure from the goal
Three moves that give you the structure
- 1Start from the decision. What should the organisation look like to do its work at the right cost, or, after a merger, how does it deliver the promised synergies without losing what makes the business run?
- 2Write the maths of the goal. Managers needed = staff / target span of control, for the type of work. Saving = (managers today minus managers needed) x cost per manager, phased and reduced for realism. After a merger: synergy gap = plan minus delivered, added up across workstreams.
- 3Let the business pick the branches. The type of work sets the right span. Routine work, such as stores or contact centres, suits wide spans. Specialist work, such as research or legal, suits narrow ones. In a merger, the industry tells you who must stay: engineers in software, relationship managers in banking, drivers and planners in logistics.
- Where do decisions get stuck?
- Key: Layers between the ward and the board
- Who must sign off spending and hiring
- Spans of ward managers versus safe practice
- Clinical leaders in management roles
This comes from decision time = layers x time spent at each layer. Hospitals need clinical sign-off, so the number of layers, not head count, leads.
- Synergy gap = plan minus delivered, by workstream
- Key: Product teams: two products still running
- Engineers leaving, and the cost to replace them
- One sales team and cross-selling
- One-time costs versus budget
Same maths, a different industry. In software, running two products doubles engineering cost and losing engineers delays the merge, so product teams lead.
Asking every team to cut the same percentage, or to try harder, ignores the type of work and the workstream that explains the gap. Interviewers score a structure that finds it.
Crack any case in five movesFinding and narrowing the real problem
Key idea
For structure, measure spans and layers against the type of work and size the change realistically. For integration, compare each synergy with plan, find the workstream that explains the gap, and fix it with owners and deadlines.
- Organization and integration
- Key: Structure
- Spans of control
- Number of layers
- Fit with the type of work
- Operating model
- Structure and decision rights
- Processes and technology
- People and skills
- Post-merger integration
- Synergy tracking versus plan
- One-time costs
- Retention, culture, communication
Two related case families; pick the branch the prompt sits in.
Names you may hear, kept as questions that fall out of the goal maths
- Spans and layers: How many direct reports does each manager have, how many levels are there, and does that fit the type of work? Where it stops helping: A wide span suits routine work but not complex specialist work.
- Operating model elements: Do the structure, processes, decision rights, people, and technology all support the same way of working? Where it stops helping: Changing structure alone rarely changes behavior.
- Synergy tracker: For each initiative: what was the baseline, the target by year, the owner, the one-time cost, and where is it now? Where it stops helping: Only as good as the baseline; agree it early.
Methods for solving this type
- Measure spans and layers by function
- Compare with the type of work
- Size the change realistically, including roles that move rather than disappear
- For mergers, compare synergies with plan by workstream
- Fix the lagging workstream with owners and dates
- Plan retention and communication
The math patterns it relies on
- Average span = direct reports / managers
- Managers needed = direct reports / target span
- Saving = managers removed x cost x share who leave the company
- Synergy gap = plan minus actual, by workstream
Worked cases
Worked case
Spans and layers at a UK retailer's head office
The prompt
A UK retailer's head office has 1,200 people reporting to 240 managers. The average manager costs GBP 80,000 a year. The exhibit shows spans by function. Does it have too many managers, and what could it save?
Interviewer-led: the interviewer shows the span table and asks for the size of the opportunity.
Clarifying questions, with the interviewer's answers
- Does everyone counted report to one of the managers listed?Answer: Yes, 1,200 people report to 240 managers.
- What span fits this work?Answer: Similar head offices run about 8 for routine work, which covers most of finance, HR, and marketing here, and 5 to 6 for specialist work such as IT.
- What happens to people in removed manager roles?Answer: About half would move into specialist roles at similar pay; the rest would leave.
A hypothesis to say out loud: An average span of 5 is narrow for a head office with a lot of routine work, so my hypothesis is that there are too many managers, but that the real saving is smaller than the headline because many managers would move into specialist roles.
The structure
- Spans versus the type of workThis comes from managers needed = people / target span, and the saving = managers removed x cost per manager.
- Average span today
- Managers needed at a target span
- Key: Realistic saving
- Where to start: function spans
The exhibit
| Function | People reporting to managers | Managers | Average span |
|---|---|---|---|
| Finance | 300 | 60 | 5 |
| HR | 150 | 50 | 3 |
| IT | 450 | 75 | 6 |
| Marketing | 300 | 55 | 5.5 |
Working it through
1. Average span today
Direct reports divided by managers.
Average span:1,200 ÷ 240 = 52. Narrowest function
HR has 150 people reporting to 50 managers, the narrowest span in the exhibit.
HR span:150 ÷ 50 = 33. Managers needed outside IT at a span of 8
IT does specialist work, so it keeps its span of 6 and its 75 managers. The other 750 people do mostly routine work and can move to a span of 8.
Managers needed outside IT:(1,200 - 450) ÷ 8 = 93.754. Manager roles removed
Compared with the 165 managers outside IT today.
Roles removed:(240 - 75) - (1,200 - 450) ÷ 8 = 71.255. Headline saving
If every removed role left the company.
Headline saving (GBP a year):((240 - 75) - (1,200 - 450) ÷ 8) × 80,000 = 5,700,0006. Realistic saving
About half move into specialist roles at similar pay, so only half the cost leaves.
Realistic saving (GBP a year):((240 - 75) - (1,200 - 450) ÷ 8) × 0.5 × 80,000 = 2,850,000
What the exhibit shows
HR has the narrowest spans and much routine work, so it is the first place to look. IT is closest to a sensible span for specialist work.
The recommendation
Yes, the head office has too many managers, and the realistic saving is about GBP 2.85 million a year, not the headline GBP 5.7 million. First, the average span is 5 and HR's is only 3, narrow for largely routine work. Second, moving the 750 people outside IT to a span of 8 needs about 94 managers instead of 165 today, removing about 71 roles, but about half those managers would move into specialist roles, so only half the cost leaves. Third, IT does specialist work and should keep its span of 6. Start with HR and finance processing, redesign decision rights at the same time so fewer layers also means faster decisions, and communicate early to keep good people.
Risks: Too-wide spans for complex work can hurt quality; Good managers may leave if the process is unclear; Savings shrink if removed roles come back over time.
Next steps: Classify each team as routine or specialist and set target spans; Redesign HR and finance processing first; Track manager numbers quarterly.
A strong candidate
Measured spans by function, matched target spans to the type of work, and turned the headline into a realistic saving.
A weak candidate
Applied a span of 10 to every team and claimed the full headline saving.
Worked case
Synergies behind plan after a Gulf logistics merger
The prompt
Two logistics companies in the UAE merged a year ago. The integration office reports that year-one cost synergies are behind plan. What should it do?
Candidate-led: you ask for the tracking data and drive; the interviewer answers what you ask.
Clarifying questions, with the interviewer's answers
- What synergies were promised, and on what timeline?Answer: AED 120 million a year of cost synergies by year three; AED 40 million planned for year one.
- How are synergies split by workstream?Answer: Procurement, network (merging warehouses), and overhead and IT.
- What about one-time costs?Answer: Budget AED 60 million for year one; AED 70 million spent.
A hypothesis to say out loud: Behind-plan synergies usually come from one or two slow workstreams. My hypothesis is that merging warehouses, which depends on contracts and physical moves, is the one lagging.
The structure
- Synergy gap by workstream, then the fixThis comes from synergy gap = planned savings minus delivered savings, added up by workstream.
- Total gap versus plan
- Key: Gap by workstream
- One-time costs versus budget
- Actions, owners, and dates
Working it through
1. Total gap
Candidate: "What was delivered?" Interviewer: "AED 30 million against AED 40 million planned."
Year-one gap (AED m):40 - 30 = 102. Share of plan delivered
Delivered divided by plan.
Share of plan (%):30 ÷ 40 × 100 = 753. Shortfalls by workstream
Interviewer: "Procurement delivered 22 against 20; network delivered 2 against 10; overhead and IT delivered 6 against 10." Candidate: "Before procurement's gain of 2, the shortfalls add up to:"
Total shortfalls (AED m):(10 - 2) + (10 - 6) = 124. Network share of the shortfalls
Network explains two thirds of the shortfalls.
Network share (%):(10 - 2) ÷ ((10 - 2) + (10 - 6)) × 100 = 66.675. Overhead and IT delivery
Overhead and IT delivered only this share of its plan, AED 4 million short.
Overhead and IT, share of plan (%):6 ÷ 10 × 100 = 606. One-time cost overrun
Spent versus budget.
Overrun (AED m):70 - 60 = 107. Cost to achieve so far
One-time cost per AED of yearly synergy delivered.
One-time cost per AED of synergy:70 ÷ 30 = 2.338. Why is network late?
Candidate: "What is holding up the warehouse merges?" Interviewer: "Two large customer contracts require service from specific sites until next year, and staff moves were delayed." Candidate: "Then the fix is contracts and a re-sequenced plan, not more effort everywhere."
The recommendation
The integration office should focus on the network workstream. First, synergies are at 75 percent of plan, AED 30 million against 40. Of the AED 12 million of shortfalls, network explains 8 (two thirds) and overhead and IT 4, having delivered only 60 percent of plan; procurement's AED 2 million ahead of plan offsets part. Second, the cause is specific: customer contracts tied to particular warehouses and delayed staff moves, so the fix is renegotiating those contracts and re-sequencing closures, starting with sites not tied to them. Third, one-time costs are AED 10 million over budget, so tighten approval of integration spending. Keep procurement moving, since it is ahead of plan, give each network initiative a named owner and date, make the chief information officer the owner of a plan to close the AED 4 million overhead and IT gap (system merge dates and moves to shared services), and report weekly to the leadership team.
Risks: Customers may resist contract changes; Staff uncertainty may cause key people to leave; Delays may push some synergies past year three.
Next steps: Open talks with the two customers on moving service sites; Re-plan warehouse closures by site, with owners and dates; Agree a dated plan with the chief information officer for the overhead and IT workstream; Put retention agreements in place for key operations managers.
A strong candidate
Found which workstream caused the gap, asked why, and proposed specific fixes with owners, while controlling one-time costs and retaining people.
A weak candidate
Told every workstream to "work harder" without finding where the gap came from.
Prompt: "Synergies are behind plan. What do we do?"
Weaker answer
Asks all teams to try harder and cuts budgets across the board.
Stronger answer
Breaks the gap down by workstream, finds that merging warehouses explains two thirds of the shortfalls and overhead and IT the rest, asks why, and fixes the specific causes with owners and dates.
Why the stronger answer wins: The strong answer finds the source of the gap and targets it. The weak one spreads effort where it is not needed.
Common mistakes, traps, and curveballs
- Applying one target span to every kind of work
- Counting every removed manager role as a saving
- Changing boxes on the chart without changing decision rights
- Tracking synergies without a baseline or owner
- Ignoring one-time costs
- Forgetting to keep key people during integration
Organization and integration questions often follow cost or M&A cases. Interviewers may test judgment on people issues as much as the numbers. Formats differ by office and change over time, so check the current process for your target office.
Practice
A Singapore company has 900 people reporting to 150 managers. What is the average span of control?
A routine operations team in India has 1,000 people. At a target span of 10, how many managers are needed?
After a merger in Saudi Arabia, the company offers retention bonuses of 20 percent of salary to 50 key people, each earning SAR 600,000 a year. What is the total cost, in SAR?
A team does complex specialist work. Which span of control is more suitable?
What does an integration management office do?
A synergy tracker shows totals only. What is missing?
Match spans to the type of work and count savings realistically; in a merger, find which workstream explains the synergy gap and fix it with owners and dates.
Sources for this lesson (1)
- Recognized public explanations of case-interview concepts and terms
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