Test coverage in software testing measures how much of the code is being tested. It's usually a percentage indicating the portion of code executed during testing compared to the entire software codebase.
Achieving high test coverage for your software project ensures that most or all parts of the code are executed during testing, increasing your chances of detecting bugs before deploying to production.
Determining the best test coverage rate depends on factors like project type and industry standards.
For instance, in the healthcare industry, optimal test coverage for medical device software can range from 80% to 100%. Due to the industry's critical nature (health and life), it comes as no surprise that the FDA mandates strict testing for medical device software or applications.
Optimal test coverage involves identifying critical areas of the software that require thorough testing. One way to do that while optimizing resources is to use “Risk-Based Testing” (RBT)
But what is risk-based testing?
Risk-based testing, or RBT, prioritizes testing efforts based on the level of risk associated with different parts of the software. By focusing on high-risk areas, teams allocate resources more efficiently, ensuring effective testing and high-quality software products.
You can use the RBT strategy to align your testing process with the potential probability and impact of failure, ensuring that core functionalities receive adequate attention during the testing.
To better understand how RBT can be applied in a real-life scenario, let’s consider the "send" or “pay” feature, which allows users to send or transfer money from their account to another account. No doubt, this is a critical feature.
In risk-based testing, this functionality would be prioritized for testing due to its importance in the app's functionality, and the potential impact of failure would result in a bad user experience or, even worse, loss of funds.
By focusing on testing crucial security parts of the banking app, you will be able to maintain a great user experience and, more importantly, secure user funds.
For you to implement RBT though, you must first identify the risks.
Now, you have a clear understanding of what RBT entails. However, to implement it, you must first be able to identify the potential risks that can be associated with the software project.
Identifying potential risks involves conducting a thorough risk, data, and SWOT(Strengths, Weaknesses, Opportunities, and Threats) analysis. This can mean reviewing data compiled about similar software projects to find out what caused them to fail or what aspects of their software were exposed to risks.
SWOT analysis involves assessing the strengths, weaknesses, opportunities, and threats related to a specific business or project. Strengths are internal factors that give the product or business an advantage, and weaknesses are internal factors that could reduce or hinder the project's performance.
Opportunities are external factors that could positively impact the business or project, while threats are external factors that could pose risks to the business or project. Conducting a SWOT analysis on the software will help you assess these four areas of the software project, especially the threats to the software project.
Another efficient way to identify risks in the software is by involving experts, business owners, developers from the same industry the software being developed belongs to, and users of the software in order to gather insights into potential risks that may affect the project.
These individuals who have experience with the software you’re working on can make valuable contributions about the potential risk associated with testing that kind of software project.
After identifying the potential risks in a software project, your next step will be to assess the probability and impact of each risk, giving you a better insight into prioritizing testing these areas effectively.
Probability is how likely the risk is to occur, like how likely it is for a company's system upgrade to introduce compatibility issues with existing plugins and themes. The impact is the consequences of the ‘probable’ risk occurring.
These consequences can include financial loss for both business and customers, security breaches, systems and plugin incompatibility, damage to business reputation or loss of crucial software data.
At this point, you or your software team already clearly understand the risks associated with the software project and must have assessed their probability and impact. The next step is to develop strategies for prioritizing testing efforts based on the level of risk.
Strategies for prioritizing testing efforts may involve allocating more time and resources to testing critical functionalities, conducting more thorough testing in areas with higher risks than others, and using tools and techniques built to address identified risks.
By focusing testing efforts on areas of the software that pose the highest risk of failure, you can ensure that critical issues are identified and addressed early in the development process. At this stage, project managers may decide to get involved since resource allocation and risk management are part of their responsibilities.
Identifying potential risks, assessing their probability and impact, and prioritizing testing efforts are all ways to focus testing on high-risk areas. However, you can go a step further by optimizing your test coverage.
Optimizing test coverage refers to the process of improving the effectiveness and efficiency of software testing by ensuring that a comprehensive test coverage was conducted.
Comprehensive test coverage means thoroughly testing all aspects of the software—not only high-risk areas but also other functionalities and components that contribute to its overall performance and usability.
When testing software, it's important to prioritize testing based on the potential risks associated with different parts of the software. For example, areas of the software that handle sensitive data (e.g. authentication) or main functionalities (e.g. transaction) may pose higher risks if they contain errors.
However, it's also important to ensure that all other parts of the software receive adequate testing attention. Software teams must learn to strike a balance between focusing on high-risk areas and covering all the other software components and functionalities.
For a comprehensive case study, take a look at this real-life research case study on RBT.
Implementing risk-based testing helps ensure that the software team tests the most important or critical parts of the software first.
By thinking about what could go wrong and focusing on those areas, software testers ensure that testing time and resources are allocated efficiently.
This way, they can identify and fix problems and deliver high-quality software products that meet customer expectations and business requirements.