What comes together, in what order, and what stays separate.
Combining the operations and the systems the two businesses run on.
Bringing the teams together, and settling who leads what.
Delivering the synergies the acquisition was made on, and holding the business to them.
Integration is where most of a deal's value is won or lost, and it is usually left to the people already running the two businesses. We do the work ourselves, inside both companies, and carry it through until the combined business runs as one.
We stay until the integration holds and the value the deal promised is in the numbers.