Full Staff Redundancy While Programming

Also known as PairProgramming.

I laughed and laughed ...

From... CostBenefitOfProcessElements... How many process checks do you run before they stop paying back? Suppose comparing early with late discovery, the payback for the procedure is 10 or 100 or 1000 times the cost. Run your equation.

One way to think of it is that if 6 people sit around for 2 hours, and find one defect, they pay for 12 work hours. If you include the running of regression (or non-regression!) test suites, writing defect reports, etc., it is quite likely that the 6 people sitting around for 2 hours achieved payback. With a defect introduction rate of 8-20 per 1,000 lines of code, there is quite a lot of process that can be cost justified (FullStaffRedundancyWhileProgramming, for example).

So another model is to find out the cost of detecting and fixing a defect at various places in the lifecycle, then work out how much process you can afford to put into place to recover that cost. --AlistairCockburn