Software Engineering Institute

One of the most important and widely discussed trends within the software testing community is shift left testing, which simply means beginning testing as early as practical in the lifecycle. What is less widely known, both inside and outside the testing community, is that testers can employ four fundamentally-different approaches to shift testing to the left. Unfortunately, different people commonly use the generic term shift left to mean different approaches, which can lead to serious misunderstandings. In this post, SEI principal researcher Don Firesmith explains the importance of shift left testing and defines each of these four approaches using variants of the classic V model to illustrate them.