My phenomenal developer, Phil Romov, suggested the title of this post based on a conversation I was having with a client. But what does it mean to say that your business is "bus-proof?" Being bus-proof mean that your organization will not be crippled if any one individual were hit by a bus or left the company unexpectedly for any reason.
This came up today in the context of a very complex spreadsheet that we're working on for a client. The spreadsheet represents a year and a half of work. One person uses this spreadsheet and only that person, with quite a bit of manual work, can really figure it out. So this firm is not "bus-proof." If the key user left it might take weeks for someone to reconstruct what its doing.
The good news is that the spreadsheet is in Excel so there a plenty of people who, with enough time, could figure out what it does. Of course the sheet is doing complex financial modeling so the issue is not only knowing Excel, but also understanding the financial principles behind the calculations. While this company isn't completely bus-proof, they could probably recover were the key user to leave the organization.
After hard coding this kind of complex, undocumented process is probably the biggest reason that systems which have worked for years all of a sudden stop working. There are many reason these situations arrive, but primarily its because people are too busy to question how well something is working until it malfunctions. Some businesses have a culture of good process documentation, but many organizations, whether because they are pressed for time or resources, are happy as long as things work. How they work is less of an issue, until, of course, somebody gets hit by a bus.