Editorial Note: I originally wrote this post for the SmartBear blog. You can check out the original here, at their site. Have a look around while you’re there and see what some of the other authors have written.
As an IT management consultant, probably the most frequent question I hear is some variant of “how can we get our defect count down?” Developers may want this as a matter of professional pride, but it’s the managers and project managers that truly burn to improve on this metric. Our software does thousands of undesirable things in production, and we’d like to get that down to hundreds.
Almost invariably, they’re looking for a percentage reduction, presumably because there is some sort of performance incentive based on the defect count metric. And so they want strategies for reducing defects by some percentage, in the same way that the president of the United States might challenge his cabinet to trim 2% of the unemployment percentage in the coming years. The trouble is, though, that this attitude toward defects is actually part of the problem.
The Right Attitude toward Defects
The president sets a goal of reducing unemployment, but not of eliminating it. Why is that? Well, because having nobody in the country unemployed is simply impossible outside of a planned economy – people will quit and take time off between jobs or get laid off and have to spend time searching for new ones. Some unemployment is inevitable.
Management, particularly in traditional, ‘waterfall’ shops, tends to view defects in the same light. We clearly can’t avoid defects, but if we worked really hard, we could reduce them by half. This attitude is a core part of the problem.
It’s often met with initial skepticism, but what I tell these clients is that they should shoot for having no escaped defects (defects that make it to production, as opposed to ones that are caught by the team during testing). In other words, don’t shoot for a 20% or 50% reduction – shoot for not having defects.
It’s not that shooting for 100% will stretch teams further than shooting for 20% or 50%. There’s no psychological gimmickry to it. Instead, it’s about ceasing to view defects as “just part of writing software.” Defects are not inevitable, and coming to view them as preventable mistakes rather than facts of life is important because it leads to a reaction of “oh, wow, a defect – that’s bad, let’s figure out how that happened and fix it” instead of a reaction of “yeah, defects, what are you gonna do?”
When teams realize and accept this, they turn an important corner on the road to defect reduction.