Costs and Benefits
How are the costs and benefits of a particular guideline calculated? The short answer is that they’re not, because the information needed to perform such calculations is not available. Information on how developers perform when reading and writing code is almost nonexistent. While there was a brief period in the 1960s and early 1970s when companies published information on the kinds of mistakes made by software developers and the impact these mistakes had on customer-detected faults in applications, it has since become very rare for companies to be willing to made this kind of information publicly available.
Academic researchers have started to publish papers listing statistics on faults in open source software. However, to date these papers have either dealt with limited subsets of faults or not gone into sufficient detail to be of use in formulating detailed guideline recommendations.