Shift Left Testing: A Secret Mantra for Software Success

The new Shift Left Testing, a DevOps mantra in Software Development:

A quick Recap of all the video tutorials in DevOps was explained in our earlier tutorial. Now, we will see about Shift left testing.

When I use the term ‘Shift Left’, you might be wondering what am I referring to Shift Left in a software??

2+ decades ago, when I started my career as a software tester there was no separate ‘Testing Phase’ for Software development and Testers Role never used to exist at all. Developers used to develop the software, test themselves and make a software release.

Further Reading => Informative DevOps Tutorial Series

The concept of Software Testing got introduced gradually when defects from the production started hitting the budget of the project and hence ‘Functional Testing’ came into effect with a very lean team of Testers. At that point of time, we were just two Testers against a team of 20 Developers.

Shift Left Testing Approach

The IT Industry started following the waterfall model for software development wherein, as we all know, the software development lifecycle goes sequentially in the order of Requirements => Design => Coding => Testing.

So, if you start from the left to right, the Testing Phase is to the extreme right of software development lifecycle.

Introduction to the Concept of Shift Left

Over a period of time, people realized the importance of Software Testing and the impact of keeping the ‘Testing Phase’ on the extreme right or at the end of the Software Development Lifecycle. This realization happened because the cost of the bug identified towards the extreme right and at the end was very high and enormous effort & too much of time was required to fix them.

There were cases where after spending so much of time and effort on a software, due to the crucial bug identified at the end, the mission-critical software could not be released to the market thereby resulting in a huge loss.

Hence, because of identification of the bug during the last stage either the release was delayed or at times, the software was scrapped by considering the effort required to fix them, which was really not worthy.

Software Development Phase

‘Defects are less costly when caught early’.

This realization and the big lesson learned, introduced a great revolution in the software industry and gave birth to a new concept called ‘Shift Left’, which means shift the ‘Testing Phase’ to the Left from Right or involve Testing at every stage and involve testers throughout.

Shift Left testing also means that just don’t test in the end but test continuously.

SDLC Phases

Shift Left approach

What is Shift Left Testing?

Firstly, the principle of ‘Shift left’ supports the Testing team to collaborate with all the stakeholders early in the software development phase. Hence they can clearly understand the requirements and design the test cases to help the software ‘Fail Fast’ and enable the team to fix all the failures at the earliest.

Shift Left approach is nothing but involving the testers much earlier in the software development life cycle, which in turn would allow them to understand the requirements, software design, architecture, coding and its functionality, ask tough questions to customers, business analysts, and developers, seek clarifications, and provide feedback wherever possible to support the team.

This involvement and understanding will lead the testers to gain complete knowledge about the product, think through various scenarios, design real-time scenarios based on the software behavior which would help the team in identifying the defects even before coding is done.

How does Shift Left Influence Software Development?

Shift Lift Approach influences Software Development in several ways.

Given below are few key points about Shift Left:

  • Shift Left approach focuses on involving testers in all and most importantly the critical stages of the program. This enables the testers to divert their focus from defect detection to defect prevention and to drive the business goals of the program.
  • Shift Left approach provides, high importance to Testing with which the roles and responsibility of the testers increase immensely.
  • With the responsibility being increased for the Testing team, the team just does not focus on ‘Testing the software to identify the bugs’, but proactively works with the team right from the initial stages to plan and build a robust and effective testing strategy by providing a great Test leadership and guidance to the team by focusing on the long-term vision of the product, rather than just taking the responsibility of the testing work.
  • Shift Left approach gives the opportunity for the Testers to design the tests first, where the tests are completely focused on the customer experience and their expectations which in turn will enable the developers to develop the software based on these tests and hence meet the customer needs.
  • Shift Left approach just does not end with the Testers alone. Moving to the let and carrying out the testing activities continuously will also allow the Developers to take more ownership of their code and increase their responsibilities on testing.
  • Shift Left approach also encourages Testers to adopt Behavioral driven development BDD and Test-driven development TDD, which helps in preventing the defects induction into the software.
  • Shift Left Testing in Agile: Shift Left approach supports forming Agile Scrum Teams which mandatorily includes Testers along with the other roles and includes Testers in regular stand up calls, other interactions, review meetings which has made the testers to have more information related to the program and hence has allowed them to indulge and involve in the detailed analysis of the software and provide rapid feedback which would help in preventing the defects grounded in the software.

Overall Shift Left testing calls for the testers to ‘Get Involved Early’, as early as possible and engage in the discussion and collaborate on ideas, requirements at every stage where the outcome of the stage has a bearing on the value of the final deliverable and also help the project to identify the risks and mitigate it in advance.

Shift Left

What should Testers do Differently in Shift Left?

Given below are few key factors to be noted as what the Testers do differently in Shift Left Strategy:

#1) Test team needs to engage early in the system right from project initiation so as to develop the integration with the rest of the team and the business to provide useful inputs at every stage of the software development.

#2) Test team should work with the Business & Operations team and gain clarity on the program and provide a clear view on demand and help in planning efficiently on resource ramp-up needs, training needs and testing tool requirements to the program well in advance.

#3) Test teams must interact with all the business stakeholders early in the software development to get a clear visibility of the product & design a unified testing strategy and plan for an optimized testing effort, analyze dependency on test environments, third parties, stubs etc, and prepare a robust automation strategy and framework and build an effective test data management plan.

#4) Test team has to work with the rest of team in providing a great Test Leadership and guidance to the team thereby keeping the long-term product vision in mind rather than just taking the responsibility of testing activities.

#5) Requirements are the key and basis to the success of any program and well-defined requirements define the success of the project. During Requirements Planning phase, Testers need to review and analyze the requirements for any ambiguity, better clarity, completeness, testability, acceptance criteria definition etc.

Also need to identify the missing requirements (if any), understand the dependencies and implementation strategies.  Clear Requirements helps the software to ‘Fail Fast' and fix all the failures at the earliest.

#6) Bring enough clarity and precision in requirements by bringing out the real examples that illustrate the features that are in use.

#7) Testers need to attend Design review meetings regularly and understand the product design and architecture and identify the design flaws, suggest alternate design options, identify the loopholes, and create test scenarios accordingly to break the designs.

#8) Testers need to carry out Static Testing (reviews) well in advance and provide feedback on key project documents so that defects are prevented from getting grounded into the software and widening its effect later.

#9) Test team should collaborate with the design and development team in providing test scenarios in advance to develop the code and address all possible real-time scenarios and business flows.

#10) Test team has to design strong and robust test scenarios so that only a few defects are identified during testing and major defects are prevented while entering into the testing phase.

#11) Testers have to Test as early as possible, be it on a standalone or local system, so that defect does not get into later stages.

The whole crux of the ‘Shift Left’ concept for Testers is to find the Defects as early as possible by all possible means.

Finding Defects using Shift Left

Benefits of Shift Left Testing

Shift Left approach works based on the agile manifesto and has several advantages too.

They are:

  • Individuals and interactions over processes and tools.
  • Working software over comprehensive documentation.
  • Customer collaboration over contract negotiation.
  • Responding to change over following a plan.

We can see that while the value is there in the items on the right, we value more for the items on the left Side.

Well, Shift Left is about bringing the idea of testing earlier in the process thereby resulting in a better and efficient testing and improving the quality of the software.

In a nutshell, Shift Left Testing process is:

  • Finding the defects early thereby reducing the cost of the project.
  • Testing continuously again and again to reduce defects in the end.
  • To automate everything and improve time to market.
  • To focus on customer requirements and improve the customer experience.

Shift Left Focus


‘Shift Left’ concept brought a huge transformation for the entire ‘Testing’ role. Until then, the sole focus for the Testing was only on ‘Defect Detection’ and now the aim of the ‘Shift Left’ from Testing perspective is a journey of ‘Early Defect Detection to Defect Prevention.

Thus, Shift Left is a Big Leap in the software industry in Software Development methodology towards speed to market, improving software quality and reducing ‘Time to Market’.

About the Author: This article is written by STH team member Gayathri Subrahmanyam. She is in software Testing since 90’s, just when the tester role was introduced in the industry. During her testing career, she has done a lot of TMMI assessments, Test Industrialization works, TCOE setups in addition to handling test deliveries and implemented DevOps practice for a huge engagement. But according to her, learning never stops…

Let us know your thoughts/suggestions in the comments section below.

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56 thoughts on “Shift Left Testing: A Secret Mantra for Software Success”

  1. Great article !!
    What is the impact of shift left with respect to timeline. Also,how do we handle or implement it in Sprint with limited QA in each team with limited timeline where QA has to understand User story and work on test case writing.

  2. Hi Ritesh,
    Thanks for your question.
    As I mentioned, one of the purpose of Shift Left is to reduce ‘Time to Market’ and improve the ‘Cycle Time or Lead Time’ (time required from code commit to code successfully running in production). The time taken to deliver the software to production drastically reduces as compared to traditional s/w development method, since everything is taken care from the beginning and the focus is on prevention than detection.
    To answer your next question,
    a. There will be a developer to tester ratio maintained in each scrum team to ensure that enough testers are deployed. Ideally it is 1 tester for 2 developers.
    b. It has been proved that, QA can handle these activities within the sprint cycle. Also, the inputs of interactions reduces the pressure on testers in easing the test case writing with a better understanding of requirements without losing much time in running around without clarity.
    Hope this clarifies….

  3. I was thinking to put my thoughts into a document and tried to search for Shifting the quality to left and found your blog. Very well articulated and presented.

  4. Loved this article! Thank you for sharing. I can’t imagine ever going back to the waterfall days. I have worked on a mature Agile team for 10 years, and I just can’t say enough about the importance of testers being involved up front. I wonder how many teams out there are still testing at the end!

  5. Lynn Rossell,

    I totally agree with you. Yes, whoever adopts to agile and ShiftLeft, they would feel very easy and comfortable with it on day to day basis. Agree, testers involvement up front is a great shift and very well needed to improve the quality of the software.

  6. Great article !!
    What is the impact of shift left with respect to timeline. Also,how do we handle or implement it in Sprint with limited QA in each team with limited timeline where QA has to understand User story and work on test case writing

  7. Great Article.
    I think this is somewhat related to V-Model. Because there as well we prepare testcases for each cycle. Please correct me if I am wrong.

  8. Ashtosh Jain,

    Thanks for reading.

    Yes, the V model of applying testing at every phase is same, but V-model again goes in sequential mode plus does not insist on the shift left culture of collaboration and interaction with the operations and business.

  9. Nice article, although the concept is not new. We did a similar practice called method one by anderson consulting. As the requirements document was being created, BA, developer, and tester had access to it, and started there process. Not only did that allow everyone to hit the ground running, it also allowed feedback to the initial requirement as to whether the use case was even valid based on current work flow.

  10. Thanks for reading Dattesh, Faisal, Sujeet.

    Sujeet, to answer your question, though not relevant to this topic, there is no time limit as such for becoming a good tester. There is nothing like good tester, bad tester. It depends on the individual personality, the testing mindset, interest, characters like questioning, eye for detail, interst of safe guarding quality, ability to put up views boldly, in addition to learning new testing concepts and tools.

  11. I am very great full to u after read all the things about testing……I have one request to you..if you are give the complete knowledge on soap_ ui teating and app testing then it would be better for us……

  12. Shift-Left is a great approach sounds professional which aligns to the DevOps model and Safe Agile methodology. However, I never observed this behavior in practice of any testers across…

  13. Simple and spellbound!

    ‘This enables the testers to divert their focus from defect detection to defect prevention’ just took it to next level.

    As a tester if one follows this approach passionately and if the stake holders take this serious and implements in their system, will definitely achieve its goal cent percent.

    Article was a real energy booster for a tester to consider their role proudly.

  14. Nalini,

    Great words..

    Yes, passion is very very important and with the real passion we can achieve anything.

    With the current SDLC approaches testers have a very strong role to play.

  15. Good article, Gayathri! We were discussing the same concept a couple of weeks back.

    Also, the article took me back to the days when I started software development and there were no testers.

    Nice read !

  16. I think we may call this “Early Testing” with all related points to early testing like to be involved, static testing, verification and so on.

  17. Interesting article! Shift Left testing must defiantly be adapted by a development team. My question would be how the Product Owner of a Scrum Team would synchronize with the test lead in order to include testing into an early stage? Sometimes the test lead and the Product owners work separately and this leads to confusions on the test strategy. Do you think that the Test Lead shall be involved on the refinements and planning?

  18. Articles on your site are really well explained with the realistic example. Was just reading your article that is about Ranorex tutorials. It is explained in such a way that many of related concepts were got cleared there. This is also in detailed justify. Well Agile and DevOps are changing the scenario’s as the teams are now collaborate more than ever before.

  19. Some proponents of Agile/DevOps Shift Left Testing are now using multiple small V&V loops to model the continual user/customer feedback. Well, imperative article.

  20. This is not a new concept. I personally have been applying this method for the last 20 years and it is a mandatory approach in spiral SDLC. Congrats to DevOps people; they gave a new name to something that’s already there.

  21. Great article … I was confirmed from this information that in all most every companies all software testers are doing this shift left testing procedures .
    Madam what I should do to learn completely about this topic? Please refer me I am fresher to testing.


  22. Interesting post, very useful in current time where we have to deliver fast with quality. We are using this model from last many years.

  23. Very good and useful article. This is being adapted by many organizations recently to reduce to TTM cycle.

    Thanks for your efforts in putting together this article.


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