There are four basic ways to shift testing earlier in the lifecycle (that is, leftward on the classic [[V-model]]). These can be referred to as traditional shift left testing,<ref>{{cite web|url=http://www.velocitypartners.net/blog/2014/01/28/agile-testing-the-agile-test-automation-pyramid/ |title=Agile Testing - The Agile Test Automation Pyramid |author=Velocity Partners | date=28 January 2014 |accessdate=27 March 2015}}</ref> incremental shift left testing, Agile/DevOps shift left testing,<ref>{{cite web|url=http://www.slideshare.net/Urbancode/shift-left |title=Shift Left: Approaches and Practices |author=Paul Bahrs | date=6 November 2014 |accessdate=27 March 2015}}</ref><ref>{{cite web|url=https://www.ibm.com/developerworks/community/blogs/invisiblethread/entry/enabling_devops_success_with_shift_left_continuous_testing?lang=en |title=Enabling DevOps Success with Shift Left Continuous Testing |author=Dibbe Edwards | date=18 September 2014 |accessdate=27 March 2015}}</ref> and model-based shift left testing.<ref>{{cite web|url=http://blog.sei.cmu.edu/post.cfm/using-v-models-testing-315 |title=Using V Models for Testing |author=Donald Firesmith | date=11 November 2013 |accessdate=27 March 2015}}</ref>
