Defect & Effort

It is observed that while keeping other factors such as skill levels, processes, tools and technology constant, there tends to be a linear relationship between defect and effort. Human errors cause defects to be introduced at a constant rate. The rate of introducing defects may however be altered by making improvements in the development process, better training, changing schedules, improved staffing, use of better tools and techniques and so on. This could also be looked at in terms of the relationship between defect arrival rate to the code development rate which in turn is related to the effort.