Shift Left Testing approach

Last Updated : 02 Aug, 2024

Introducing Testing early in the Software Development Life Cycle, is a concept commonly referred to as shift-left testing. Historically, testing has been done at the last phase of the development cycle this implies that most defects are found at this stage, resulting in more costs and more time spent on projects. However, Shift Left Testing seeks to perform these testing activities before the designated time hence the term ‘Shift Left.’ This makes it possible to involve the developers and the testing team right from the design phase and prevent the accumulation of a large number of impediments to flow.

Table of Content

Software testing is a necessity. It ensures that a product is being released to end customers without faults. And being a widely discussed topic, there are many approaches to testing software. Some companies champion a “ waterfall approach” to product design. Here, the software is designed sequentially. It strictly goes through the development cycle of:

Requirements/Gathering
Design
Development
Deployment

Testing is delegated to the end stages of the product design (before the deployment stage). This is normally called “shift right testing”.

Testing at the End Stages – An Inferior Strategy:

All codes are prone to bugs. Bugs can be minor (low risk) or major (high risk) depending on the type of error. The earlier those bugs are caught, the better. It allows time for development teams to fix software without delays and avoid prolonged end-testing phases. It’s also easier to fix bugged software when too many bugs aren’t showing up at the same time. This is the reason shift-right strategies are ineffective in most cases. Realistically, it’s exhausting going through every coding line of an end product – just to find a bug or two. It’s better to fix each unit as the code is being developed. And this is where shift-left comes in!

Improved Code Quality: The earlier you detect a bug, the better. It allows for better communication between testing and developing teams. It allows both teams to address each bug one-by-one. Contrast that to a shift-right approach. Here, all bugs are addressed at once. And many may be forgotten or ignored (due to time or budget constraints).
Multiple test types: When codes are tested at each design stage – a multitude of test types can be applied. For example, unit testing is a possibility with a shift-left approach. Here, each component is tested separately to check for individual bugs. Also, integration testing can be done frequently across the design stage. This ensures that bugs don’t develop as different units are assigned together. Contrast that to shift-right strategies, which only allow for the possibility of system testing. And even that isn’t accurate and isn’t effective at discovering all bugs.
Finding design defects and architectural problems: Sometimes, bugs aren’t the problem. Major aspects (or ideas) that are being implemented that may be defective. Those defects (which may interfere with other codes) should be discovered early. Otherwise, too much time is wasted on implementing major design plans that are unfeasible. This is another added pro of shift-left testing. After all, smaller unit tests are automated, and their test cases are easy to design. Contrast that to system testing – which takes time, and must be done manually. It also can’t be repeated often. And that repeatability is what makes shift-left approaches better. It allows for a product of better code quality, reducing the chances of high-risk errors!
Reduced development and testing costs: Bugs that are caught early reduce the chances of side effects. With fewer side effects to worry about, product launches can be done on time. A final code can be delivered to the end customer without needing future fixes. Here, it’s recommended that bug tests are done after every build. This allows for better automated continuous testing, which is impossible with large bug sizes. Also, shift-left approaches reduce the need for system testing. And in fact, that might be eliminated if testing is done frequently.
Fewer problems for future versions: Many software is designed with online features. They’re also designed with the intention of patching future versions. Those future versions cannot be added in – if prior versions have unfixed bugs. This leads to a “bow wave” effect, where multiple bug side-effects might stack. The result is, certain bugs become impossible to fix.
Keeps all project stakeholders informed: With the shift-left approach, testing is done at each critical stage of the software’s development. As a result, the testing team ends up (by necessity) being involved in the planning of the project. They’re also informed on its business goals. This lets them gain a better perspective on the software’s purpose. And it allows them to find creative ideas and solutions in the middle of testing. Plus, it keeps them motivated. Because testing teams understand what their efforts contribute to in the long-run.
Keeps the developer team conscientious: Many design projects put developers in the position of creating code. But what about checking quality while writing each line? This mindset is ingrained into developers by encouraging frequent testing. And since testing requires time-consuming revisions, it ensures that a developer minimizes errors while writing code. With a shift-left approach, developers are encouraged to be more responsible. And it also enhances their skills and proficiency levels!
Improved testing collaboration: Shift-left approaches take advantage of frequent “automation”. It lets them perform continuous testing to reduce time. But, that still leaves the problem of designing those tests. And this is often left to the testing team to figure out. Also, the problem here is, designing the best tests requires knowing the purpose of the product, and it's business goals. With a shift-left approach, since developer and testing teams work together – they can design automated tests with each other’s’ input. This leads to the development of testing scenarios that are realistic and accurate at finding bugs and problems.

Why Adopt a Shift Left Strategy?

Early Detection of Defects: Since the test activities are introduced into the development process at an early stage the defects are easily detected and rectified. This helps to minimize the cases and cost of servicing bugs within the program because they are easily spotted in their early stages of development.
Cost Efficiency: It is seen that the cost of correcting defects is relatively high in the later phases of the SDLC. This way the cost and time needed to address these bugs is kept to the bare minimum.
Improved Quality: The digitization process comprises several phases that are tested and fine-tuned to meet the quality produced. This in turn results in a more stable and reliable release.
Faster Time to Market: The problem is that failure to identify these issues early will slow down the developmental process and thus will consume a lot of time in the final stages of testing and fixing defects. This helps bring out quicker releases as well as delivering features to the end-users at high speed.

Is Shift Left Always Appropriate?

On the same note, despite the various benefits that come with the shift left strategy, it may at times be disadvantageous, especially to certain projects or teams. Some conditions implying this approach include the size of the project. The complications of the project and The structure of the working team. For instance, in the context of simple project structures, such as when the project size is small, there could be large costs associated with early testing. Moreover, there may be tasks that can be conducted only at a certain phase of a project’s implementation. Due to these considerations, there is a need to evaluate the project's particularities to identify whether Shift Left can be implemented effectively.

Main Benefits of Shift Left Testing

Enhanced Collaboration: Early access to testers makes the flow of communication between the developers, testers, and other team members effective. This results in increased togetherness of the team and understanding of the project specifications that are necessary in the project.
Reduced Risks: The identification of defects and issues at an early stage enables the teams to control possible risks before they get out of hand. This early intervention reduces the effect of problems on the end result, which is a proactive way of handling an event.
Continuous Improvement: In this phase, integration and further testing take place i.e., testing is carried out intensively and in real time allowing teams to fine-tune the software product based on feedback from the users as well as other quality checks.
Better Test Coverage: Thus, the early entry to the development cycle enables testers to come up with more elaborate test plans that capture as many facets of the application as possible. This leads to improving the tests and coming up with a very high quality product.

Picking the approach that works for you:

Shift-left approaches can be practiced in a multitude of ways. And they suit software of all sizes (from large online platforms – to small mobile apps). As a result, you’ll find that your design deadline differs based on the project. And as a result, the approach you pick differs.

Model-based: At least half of a given software’s bugs appear during the requirements gathering phase. Finding bugs in that stage reduces any need to fix bugs later on. Plus, they keep testing teams informed on the basic goals of the project.
Traditional testing: Here, the focus is on continuous testing, through unit and integration tests. It focuses on automation as much as possible, thus saving time and development costs. This form of testing tends to ignore acceptance and system tests (whose results are more or less guaranteed through frequent unit/integration tests).
Incremental testing: This tries to mimic a traditional testing model – but it’s aimed at large projects. Testing is broken down into minor pieces, where a set of codes are tested. After codes are integrated together, they’re tested again to ensure a lack of bugs.
DevOps/Fragile testing: Performed less frequently than traditional models, this form of testing works for smaller projects that have tight deadlines.

Best Practices for Shift-Left Testing in Agile

Automate Testing: Among the types of the tests that are commonly suitable for automation are unit testing, integration testing, and others, as these types of tests actually help save a lot of time and effort. Since automated tests mimic real users, they can be run more often to find problems before they are reported by live users.
Continuous Integration and Continuous Deployment (CI/CD): With the help of CI/CD pipelines one can integrate the code changes and test on a regular basis. Among them, relevant problems can be identified and solved promptly, and the flow of development can be optimized, so that the work goes well.
Early Involvement of QA: Incorporate QA engineers right from the start of the project to understand what test strategies are to be created, how test cases should be framed, and any possible problems that may be anticipated. This means that testing is incorporated throughout the entire process of the Software Development Life Cycle.
Collaborative Planning: Get the developers, testers, and product owners to sit together especially during the planning process. This way, all the participants will be aware of the expectations of the project and the testing regime in equal measure.
Emphasize Test-Driven Development (TDD): By integrating TDD practices, one is able to write a test before writing the codes of the actual program. This amounts to ensuring that the issue of testing and quality assurance of the software is incorporated right from the moment of coding to enhance the reliability of the developed software.

Conclusion

Therefore, Shift Left Testing strategy is one of the most effective that can enhance the quality, speed, and cost of software development. Thus, if testing activities are incorporated into the SDLC at an earlier stage, the tasks could be easier to address, and the risks minimized with concomitant outcomes of improved product quality and time efficiency. But there is a need to determine the applicability of this approach to each project and apply measures to enhance the positive impacts of the method to the maximum extent possible.