This is more common than you think. Not just losing data, but not having a good handle on where the important parts of the system are, and how close you are to

This is more common than you think. Not just losing data, but not having a good handle on where the important parts of the system are, and how close you are to catastrophe. I find diagrams really help. I can recall a visual map of the system when I work on some component, and think, "OH, I remember seeing this component connected to a really critical thing, I need to check something first." Start by creating one empty page for every component of your system. You won't remember them all, but over time you can add missing ones. Each page is the authoritative source of info on that component. If you need more pages for one component, put them in a directory of the same name as the page and add ".d" to the directory name, and link to them from the first page. Finally, create a diagram (however you want) that includes every component you have a page for. Add the count of components to the top of the diagram. If the count on the diagram doesn't match the number of documents, time to update the diagram. If you ever add, remove or rename a page, time to update the diagram. If you do this the same way for every different system you have, you can link them all together and get both small and large scale diagrams. (p.s. don't waste time automating this unless you find the system changing constantly or you have a very big system)