Software Testing and the Impact on Quality

My response to a question on Reddit.

That statement is similar to the idea you can’t inspect in quality. Basically “Inspection is too late. The quality, good or bad, is already in the product.” W. Edwards Deming

I agree with those ideas. Software testing is a bit different (at least some of it is) from the inspection mentioned above. You are testing while the product is being developed and adjustments are being made before the product is released to customers. Also with internet based software you have the ability to update the software and now all users have that update. Where for physical devices they already have the product and the only option is a recall which is very expensive and often ignored.

Software testing however should pay attention to those points in the 2 links above (defects should be understood as evidence of a process that needs to be improved so defects are not built in the first place). What you want is not just to fix the bugs software testers catch but figure out the reasons those bugs were created and improve you process so you create fewer bugs in the future.

No matter what the software quality is based on the code that is written. At the best software testing can tell people about the bugs but unless the code is fixed the software quality didn’t change. But to say that software testing doesn’t have a big influence of software quality when testing is well done and the software development process is good (listens to feedback and improves) is not very accurate.

Related: Improving Software Development with Automated Tests – Combinatorial Testing for Software – Building a Great Software Development Team – Deming and Software Development – The Defect Black Market