Azura Othman, Noorul Ahlami Kamarul Zaman and Rajashekara Swamy
One of the key challenges in traditional testing method is testing activity being pushed towards the end of development lifecycle. As a result, the time given for testing is short but the expectation is to have maximum test coverage. In addition, late identification of defects in development cycle can result in major re-work and further delays. Based on these experiences, we have attempted to adopt Shift-Left testing approach, which is considered as one of the best practices in the industry.
In reference to , the method is to perform testing earlier in the lifecycle, test early and often.  There are four methods of Shifting Testing to the Left. These are referred to as Traditional Shift Left testing, Incremental Shift Left testing, Agile/DevOps Shift Left testing, and Model-Based Shift Left testing. This paper explains the experiences in applying Model-Based Shift Left testing method.
International Journal of Emerging Technology and Advanced Engineering, V9 I8, August 2019