What is Shift-left testing?
In software development, “shift left” is a concept that the team is moving tasks or activities earlier in the development lifecycle. The idea behind shift left is to identify and address issues as early as possible, reducing the cost and impact of finding and fixing problems later in the process.
So, applying the shift left approach to software testing means starting the testing activities earlier in the development lifecycle.
What advantages does shift-left testing provide?
- Cost and time savings: shift-left testing helps minimize the cost and effort required for bug fixing in later stages of development. It saves time by reducing the need for extensive rework and retesting.
According to a study by the Ponemon Institute in 2017, savings can range from about 10-100 times the cost. For large-scale projects following traditional development processes, if a major bug is detected during the development phase, it will only cost around $80 (charging 1 man-day for BA/developer) to fix. But if it reaches the testing phase, it will cost around $960 (12 man-days for QA & PM & Developer & BA & PO, etc.), and fixing that defect in production will cost approximately $7600.
However, according to the NIST report in 2020, the cost of fixing issues in production in 2019 for software development is more than 30-60 times higher (depending on the security issue) compared to detecting and fixing them early in the research and infrastructure-building phase.
- Faster time-to-market: Defects are detected and resolved promptly, allowing for faster product iterations and shorter release cycles. The project team can deliver a reliable product earlier than expected. It is really good news.
- Improved software quality: With shift-left testing, quality assurance is integrated throughout the entire development lifecycle. This leads to higher quality software products as issues are addressed and resolved proactively, resulting in improved user experience and customer satisfaction.
How to apply Shift-left testing effectively
The effectiveness of shift-left testing depends on the specific context and project requirement. We need to evaluate and adjust your approach based on the progress and outcomes of the project. To apply shift-left testing effectively, here are some general guidelines:
- Standard Development: In order to ensure a smooth software development process, the team needs to have a common set of standards across requirements gathering, development, and testing. This includes aligning on practices such as writing requirements, adhering to coding standards, and following consistent testing protocols. When all team members are aligned and operating under the same standards, several benefits arise. Review or testing activities will be faster.
- Start testing early: Begin testing activities as early as possible in the development lifecycle. This could involve testing during the requirements gathering and design phases, rather than waiting until the development is complete.
- Testing objectives in each stage: The Testing Pyramid should be applied by decreasing the number of test cases from the unit level to the end-to-end level. We also avoid duplicating testing efforts on the same target by identifying the testing objectives at each stage of the pyramid and it is communicated to all team members, preferably with documented templates.
- Collaborate closely: Encourage discussions about requirements, design, and potential issues to ensure everyone has a shared understanding.
- Automate tests: Utilize test automation tools and frameworks to automate repetitive tasks and assess the quality of source code generated in each developer’s environment.
- Focus on testability: Collaborate with the team to write the user story and design the feature that is easily testable.
- Optimize customer involvement: Embrace the ideal of the Hybrid methodology of Shift-up testing vs Shift-left testing, where quality assurance is the obligation and right of all stakeholders, not just the development team. Specifically, the customer is the one who needs the clearest understanding of shaping the product. This helps the development team gain the most authentic view of the product they are building and its intended purpose.
Does the Shift Left approach always suitable for every scenario?
A Shift Left testing approach may not always be suitable. In some cases, traditional testing approach or Shift Right testing strategy can be beneficial such as short-term project, or project related to enhance customer experience.
