Post-acquisition integration sequencing, ordered by where value is created and destroyed.
Integration playbooks open with branding, systems and synergy capture, because that is what playbooks have always opened with. The integration data describes a different window. Very little value is created in the first 100 days, and yet 73% of the value that underperforming deals eventually lose is already locked in by day 100, mostly as customer and key-person attrition.
The ledger reorders the window around where the risk actually sits: revenue protection first, decision rights across the seam second, cost synergies third, systems last. Every integration action is on the ledger with an owner and a week, and every deferred action is on it too, with the reason, so what is deliberately not done in the window is as explicit as what is. The sequencing comes from mid-market deals, and we would not extend it to a deal whose whole case rests on a systems consolidation, because there the migration is the value and deferring it defers everything.
Revenue protection as a named workstream: key customers contacted by name, key people retained by name, pricing discipline frozen. Nothing else outranks this.
Day 1–30One decision-rights ledger across the seam of the two organisations, published on day one and tested against real decisions by week six.
Day 1–45Cost synergies begin only when protection metrics hold; systems migration is scoped but deferred out of the window unless the deal case dies without it.
Day 30–100The ledger is maintained weekly against two numbers: customer retention and seam decision latency. They move before any synergy number does. This is also the youngest instrument we publish. It sits at its first edition and has not yet been through an application review, so read it as the sequencing our integration sample supports rather than as a method that has survived revision.
Mid-market acquisitions and mergers, from close through day 100.
Integration rescue, where a conventional plan has consumed the window and the attrition is arriving.
Deal diligence, read backwards: pricing the integration risk the target’s customer and management concentration implies.
Derived from the 28-integration sample and applied in every Markham integration since. The sample is where the sequencing came from, so it evidences the pattern rather than testing the method:
The Institute stewards the ledger and revises it after every tenth application review. That review has not happened yet. Changes are versioned, and superseded editions remain citable.
Cite as: Markham Institute, “The First 100 Days Ledger”, MKM-F-009, v1.0 (2024).