We're in a bad situation of having very little documentation on customization our past workers made to a business critical system. Lots of changes were done to Crystal Reports, database entities, and proprietary configuration/programming files for our ERP software.
The current documentation generally reads something like this:
This program is run before invoicing. Known bugs: none.
Run this program after installing software X.
Changed the following fields in this report: (with no explanation of how or why)
Our IT shop is small, and in the case of the ERP software, most work was lumped on one person (that's me now) so no one else here knows what all we did. The IT and accounting department know bits and pieces (occasionally quite helpful ones) but it's not enough.
Another problem is our Accounting department seems to think we're well documented. It's true that we kept lots of records of what went wrong, but very little explains what (if anything) was done to fix these problems. We have hundreds of papers explaining bugs, but the documents explaining changes (as shown above) are almost useless.
How can I go about documenting past changes when I don't know what all was done? I can start with documenting what we've changed: Files, database tables ect which we need to have for the system to work. I can also document what we do; when reports are run, why people were told to use X report/program. But when one of these customized things has a problem, I'm always back to square one.
How can I proactively document this stuff for myself and others?