Bugs are unpredictable. Fix them first

Bugs, by their nature, are unpredictable. They are complicated due to predicting how long it would take to fix them. Fixing a bug could take two minutes or four days to understand its cause, let alone put in place a fix.

The unpredictable nature of bugs creates an environment in which the whole system becomes uncertain. Software development schedules have no meaning with open bugs. The uncertainty affects the team’s velocity and accuracy in the medium to short term.

Unresolved bugs increase the risk of future changes.

Development teams updating a system are at a higher risk of allowing bugs to creep through customers’ experiences. The accumulation of bugs leads to less predictability for feature development. Unresolved bugs lead to an uncertain environment, lowering service quality.

Bugs tend to become obsolete pretty fast in applications that are updated. The steps to reproduce become irrelevant, the functionality changes, and the impact of the bug often gets lower.

Fixing bugs first creates predictability. A bug-free codebase removes this uncertainty, making it easier to predict how long new feature development will take.