There used to be this 1:10:100 Rule, which basically expressed that the cost to fix a defect increases exponentially the later in the development lifecycle that it is identified.
* A defect caught in requirements phase costs a factor of 1 (1x) to fix.
* A defect caught in construction costs 10 times as much as in requirements.
* A defect caught in production costs up to 100 times as much as in requirements.
Do you think this is still valid? Do you know anyone still using this rule of thumb? Saving Changes...
The rule was valid for certain conditions and if these conditions exist in a project then the rule would still be valid. I still see projects following traditional waterfall approach to development with more emphasis on "trying" to lock the details at the beginning of the project. Defects found in such projects seem to follow the rule closely. Saving Changes...
Derek HuetherPrincipal Solutions Engineer| AtlassianNew Market, Md, United States
Bas,
I do think this formula is still valid but I add a little something extra. I also leverage the Pareto principle when deciding whether to actually fix the defect. Chances are, we're going to correct 80% of defects with 20% of the effort. We're probably going to find 20% of the defects hold 80% of the value. What's my point?
By knowing the point of the lifecycle the defect is caught, the 1:10:100 rule is going to help you identify cost to fix. But, what is cost if not balanced by value? What good is information if it does not aid you in making measured decisions?
