Definition
The standard process for integrating a newly acquired company into the existing operating system; teaching material 34 gives an operational onboarding window of the first 90 days after closing, covering only the lean and operations portion, not the completion deadline for the entire M&A project—legal, finance, HR, and IT have separate workstreams.
In detail
Acquisition Integration is the standard process for connecting a newly acquired company into the existing operating system, centered on the lean and operations onboarding in the first 90 days after close (textbook 34 definition), with legal, finance, HR, and IT running separate workstreams. It addresses how to quickly stabilize the team, align strategy, and introduce the management system after an acquisition, avoiding cultural conflict and performance decline. Unlike Strategic Plan (selecting targets) and financial due diligence (valuation), it focuses on post-close execution. Typical outputs are a 90-day operations onboarding plan, integration milestones, and a model line build plan; retention rate and system acceptance are ABS leading observation items, not official standard metrics.
Example in practice
When a manufacturing company acquires an upstream supplier, after the deal closes management finds that the two sides differ greatly in quality standards and production processes, and employee morale is low. At this point the Acquisition Integration process is launched, an integration team is formed, and a 90-day operations onboarding plan is created, including process alignment and quick wins; legal, finance, HR, and IT proceed in parallel along their own workstreams. The team tracks retention rate and system acceptance as leading observation items, ultimately achieving a smooth transition and laying the foundation for subsequent business growth.