Benefits & Types of Shift Left Testing

Shift left testing is a concept based on the theory that if developers test code as they develop it, they'll be able to uncover issues sooner (and fix them faster) than if they put testing off until the final stages.

Shift left testing encourages multiple testing phases starting early on in the development cycle. Agile developers were quick to adopt the shift left approach, but any team can benefit from this testing process.

So, what does shift left testing have to offer your development team? Let's dive into why you should use shift left testing in your future projects.

Test More Code, More Frequently

Perhaps the biggest benefit of shift left testing is that testing begins earlier in the development cycle and teams engage in more tests overall, which means that a larger percentage of a project's functionality is put through its paces.

If a team of developers was to postpone testing until the final stages, which is the traditional approach, they'd likely only test the most critical functionality.

Of course, in order to achieve more frequent tests, teams have to make the move from manual tests to automated tests.

Shift left testing is made possible with the use of automated testing tools, which save teams time by allowing tests to run periodically in the background as the developers keep working.

Each time a test completes, the team members review the results to uncover potential issues, and they prioritize those problems before they continue coding, allowing them to clean up performance as they go.

By the time they reach the final stages, manual testing takes place as usual, except they're able to focus on key areas and there's less work left overall, since they've been testing and improving quality all along.

Generally, shift left testing makes use of the fact that bugs are cheaper and easier to fix early on in the development process, which means that shift left testing ends up saving a dev team countless hours.

This reduces development costs and time to market while improving overall code quality and performance. That's a win-win-win for the team, company, and future users.

Types of Shift Left Testing Methods

Shift left testing is merely a concept that entails testing more often early in the development cycle. Once you begin looking into it, you'll reveal four different types of shift left testing, each one offering its own set of advantages.

1. Traditional Shift Left Testing

The traditional approach to shift left testing aligns with the V-model, which is an extension of the most widely used software development life cycle (SDLC) models known as the waterfall model.

The V-model, which is also called the verification and validation model, associates a testing phase with each phase of development.

In combination with the V-model, the traditional shift left testing process focuses on unit testing and integration testing, which is achieved using API testing and Selenium tools. The traditional shift left testing approach puts more emphasis on system-level and acceptance testing.

2. Incremental Shift Left Testing

If you're developing a large and complex software system, the incremental shift left testing approach is likely most applicable.

Large, complex development projects are difficult to manage — it's almost impossible to get tasks and deliverables lined up at once. So, these projects are often broken down into smaller components that build upon each other incrementally.

With each incremental delivery, development and testing are shifted to the left. In other words, incremental tests take place with each increment of the development cycle.

3. Agile/DevOps Shift Left Testing

If you're taking the DevOps or agile approach to development, you'll implement shift left testing in a way that emphasizes continuous testing, often through multiple sprints.

Multiple sprints throughout development allow you to test the project as it builds upon itself, making this method ideal for developmental testing. However, the team will pivot and take a different approach once operational testing begins.

4. Model-Based Shift Left Testing

Shift left testing is based on the idea that by testing earlier, you can catch bugs before they become a big problem or costly fix.

However, model-based shift left testing takes things a step further, beginning in the requirement gathering phase where an estimated 65 percent of defects are actually introduced.

All three other models of shift left testing miss this stage, though, making model-based shift left testing the earliest identifier of problems — long before software development even begins.

Implementing Shift Left Testing

As with any new approach, implementing shift left testing requires planning, discussion, and investment from crucial stakeholders.

Getting the buy-in of the development team can prove difficult, simply because more testing might sound like more work.

However, in reality, shift left testing is designed to save time. The key is knowing how to implement shift left testing with the right tools and approach so that you don't waste time or create extra steps in the development process when you're trying to improve efficiency.

If you're considering adding shift left testing to your development cycle, but you're not sure where to start, let Adservio professionals lead the way.

We've helped countless companies improve efficiency in development and bring their applications to the next level through innovative practices and advanced tools.

Contact us today to learn more about how we can help your team get more done in less time.