Software Defects & Why Encouraging High Quality In Software Matters

[E]xcessive defects [in software] are the biggest waste in software development. The numbers on this are staggering and show several orders of magnitude variation. Capers Jones2 reports that in 2000, during the dot-com bubble, he measured software quality for North American teams that ranged from 6 defects per function point down to less than 3 per 100 function points, a range of 200 to 1. The midpoint is approximately 1 defect per 0.6 to 1.0 function points. This implies that it is common for teams to spend more than 90 percent of their effort fixing defects. As direct evidence, late in 2007, Aaron Sanders, an early proponent of Kanban, reported, in the Kanbandev Yahoo! group, that a team he was working with was spending 90 percent of available capacity on defect fixes.


2. Jones, Capers. Software Assessment Benchmarks and Best Practices. Boston: Addison Wesly, 2000.

-- David J. Anderson

from "Kanban"

Quoted on Wed Jul 25th, 2012