The «Shift Left» strategy in testing

The demand for quick release of high-quality software products continues to grow worldwide, so teams are experimenting and using new approaches to development. The Shift Left strategy is perfect for such purposes because even in Agile teams, which move away from the traditional Waterfall development model, testers get involved in the process only at the final stage. This is one of the main reasons a software project runs out of budget or time.

Features of the Shift Left strategy

The main feature of this approach is, literally, a shift to the left and testing of individual software components immediately after their development or integration, rather than at the end of software development. That is, developers perform more tests before sending individual units to the version control system. Thus, by performing special tests, both testers and developers take responsibility for the quality.

Advantages of the Shift Left strategy

1. Error and defect detection at early stages of the development life cycle.
2. Lower maintenance and testing costs. Resources are likely to be used to their fullest potential with less downtime (for example, for the test environment). 
3. The end product is of higher quality due to fewer fixes in the code.
4. The higher likelihood for the end product to meet the deadlines.
5. High level of client satisfaction due to the code stability and staying within the budget.
6. It’s possible to achieve and maintain a higher quality of the code base.
7. Painful test support is prevented. When a test suite has vulnerable tests, even a minor change in the code can lead to a test failure.

The main disadvantage of the Shift Left strategy in testing is that in order to implement it successfully, a radical change in culture must first take place, which requires a collective effort. Teams usually tend to prefer traditional approaches to the development process. To make the transition, you should take into account the fact that you will need to change methods, processes, skills, tools, etc. It is also important that the company's roles are properly aligned.

Overall, the benefits of this technique are more significant. Testers will have to share some of their work with developers and assign them more testing. In teams that have been practicing the Shift Left strategy for a long time, testers become «coaches» and teach developers how to write better code, avoid bugs, and perform their own unit testing. The advantage is that a tester, who used to be busy writing test cases, now has time to delve deeper into the product, work on business cases, performance testing, implement smarter testing solutions, etc. This distribution of testing responsibility leads to a higher level of quality achieved.