5. Don't Put Off Till Tomorrow ...
System documentation is IT's version of a cluttered attic. Sure, we know we should get it organized, but there's always something better to do.
If M&As are in your company's strategic plan, find the time to get documentation in order. We can't recall a CEO who proclaimed a merger a success because of the great documentation IT had maintained over the years, but we know plenty who'll curse the lack of it when an integration goes south.
Never is information about your systems more critical than during the initial due diligence. Not only does it validate the value of the transaction, but it also brings you to the decisive point in time when you should be planning how to integrate operations.
For the buyer or the seller, there are two key actions. First, gather all the system documentation from your counterpart as soon as you're allowed. Second, schedule and implement a full network scan for systems and other IT assets. Identify every major asset picked up by the scan and match that list against the documentation inventory. This process may be unreasonable for a very large enterprise, but attention can be focused on a major site or data center. Not only does this process validate the claim of the acquired company's physical assets, it also checks the accuracy of the documentation provided by the seller.
These two steps combine to produce the final documentation. The benefit of the "new set" is that it should match the formatting of both companies' documentation, right down to correlating applications, workflows, field names and definitions, and relationships among data and systems.
This is also an effective way to identify data elements or processes that don't fit into your existing business operations. Once you have a common footprint, you can discover how information and systems are used--before tossing anything out (see item No. 2). Too often, organizations want to jump ahead in the process and redesign workflows, teams, and systems. Go bottom up and avoid missing, or mismanaging, a system or data set in a way you'll regret later.