As long as the final product is sound and free of defects and errors, the overall efficiency and effectiveness of the error removal process in software development is rarely a major concern — at least from the perspective of the buyer. It is an understandable position, especially since most buyers are satisfied with a vendor capable of providing the on-time delivery of quality software that meets the buyer’s initial expectations and falls within the original cost guidelines.

Although this seems to be a perfectly sensible position for any buyer to adopt, it is easy to conclude that most buyers would become far more interested in the importance of the error removal process if they were more keenly aware of the direct relationship between software development cost and error removal efficiency.

It is for this reason that buyers ought to become more familiar with the most critical error removal metrics, as a software development team capable of efficient and effective error removal processes is more likely to deliver cost-effective results while maintaining high standards for the overall quality of the software that is ultimately developed.

The Cost of Identifying and Fixing Errors

Unfortunately, both buyers and vendors tend to underestimate the short- and long-term costs associated with identifying and fixing errors during the software development process, not to mention the costs that will continually add up if any errors or bugs are allowed to remain in the released version of the software. According to one estimate that used a large software system with a function point size range of 10,000 as an example, nearly 50 cents of every dollar spent on development was devoted to identifying and fixings errors and defects over the system’s 25-year life expectancy.

When one considers the error removal costs associated not just with the development process but also the costs generated after the release of the software, it becomes much easier to understand why error removal and defect repairs are often considered the most expensive aspect associated with the development of high-quality software. For buyers, these potentially exorbitant — and often unseen — costs underscore the need for tools capable of accurately measuring the efficiency and effectiveness of a software development team’s error removal processes.

Measuring Error Removal: Operator Errors and Defect Removal Efficiency

For buyers, it should now be quite evident just how critical it is to understand which metrics are most useful in determining the overall effectiveness of the software development process — with error removal being particularly essential due to the reasons previously outlined. In addition to ensuring cost-efficient processes, several error removal metrics also provide some insight into the overall quality of the software created by a software development team, adding even more value for buyers who understand and apply these particular metrics.

Operator Errors

When a software development team is assembled, it is the goal of the leadership group to ensure that the team is comprised of individuals possessing complementary skill sets that account for all the different and complex components that make up the software development process. Without this kind of balance, the existence of any kind of skill gap within the team often results in operator errors that needlessly inflate the costs associated with identifying and fixing errors in the software.

A leadership team that makes use of this metric — which is designed to accurately outline operator errors — is much more likely to quickly identify and fill any skill gaps that might exist on the development team and can then begin the process of developing specific strategies to ensure these kinds of operator errors are avoided altogether as the development process continues. This benefits the buyer tremendously, as cost-efficiency is made more likely due to the simple avoidance of issues associated with overlooked defects or improper documentation stemming from operator errors.

Defect Removal Efficiency (DRE)

In terms of measuring error removal efficiency, DRE (Defect Removal Efficiency) is one of the most accurate and useful metrics available to those overseeing the software development process. This metric compares the number of defects in the final project to the number of defects reported by the software testing team, providing insight into just how efficiently team members are able to identify and address errors and defects that exist in the software.

Ideally, the software testing team’s DRE rating should be as close to 100 percent as possible, as this indicates that the team is remarkably efficient in identifying, removing, and resolving the errors that exist in the software being developed and tested. A DRE rating close to 100 percent also reveals quite a bit about the overall quality of the software, something that other error removal metrics often fail to account for.

Combining Prevention, Pre-Test Removal, and Testing for Efficient and Effective Error Removal

Buyers who understand the often complex processes associated with software development are better positioned to select a development team capable of delivering high-quality software that is both on time and on budget. When selecting a vendor, it is therefore critical for buyers to discuss the development team’s specific strategies for measuring error removal and how they intend to create an efficient and effective development process from beginning to end.

Although every team operates differently, it is often the case that the most effective development teams favor some combination of prevention, pre-test removal, and thorough testing practices to ensure efficient and effective error removal processes. Through the use of a synergistic approach that incorporates prevention, pre-test error removal, software testing tools combine with sound testing strategies, these teams are able to produce the high-quality and cost-efficient software buyers so frequently seek.