Legacy Documentation should be a priority

If you had to produce documentation for your legacy application tomorrow, could you do it? Maybe not tomorrow...you would have to find it. What about next week? That would give you time to find it, but it's a hard copy so it needs to be scanned and reformatted. A month from now? The information isn’t updated; that will take some time. A year from now? Surely that’s enough time to get the whole thing rewritten, but almost everyone who knew how the system really works has left the company, and the few remaining will be retiring soon. 

Documentation of your legacy system is very important for a number of reasons. People are still using it! New hires will benefit from having a reference. Auditors may require documentation of your internal processes, which would include interactions with the legacy system.

When it comes time to migrate the applications to a new platform, the documentation becomes an invaluable tool for insuring that the new system functions the same as the old one. Even in the worst-case scenario, where the source code for an application has been lost, adequate documentation can be used as specs to facilitate a rewrite on the new platform. 

The point of all this is to encourage you to make sure you have current documentation now, before it becomes a crucial issue. Resources may have to be pulled away from other tasks that are also important. Time and cost may have to be justified to upper-management. It’s easy to find an excuse to put it off, but that will only make it more time-consuming and costlier in the long run.