It’s essential to deliver fully functional software. But the system’s non-functional requirements are equally important.
A critical step in software testing and quality assurance, non-functional testing evaluates a system’s attributes beyond functional requirements. This type of testing focuses on assessing qualities such as usability, reliability, security, and performance for areas of improvement before production.
Definition of Non-Functional Testing
Non-functional testing is the process of evaluating a software system’s operational aspects instead of focusing on its specific functionalities. It involves assessing the system’s operational characteristics, focusing on studying how a system works under stress.
A non-functional test aims to assess crucial factors that could significantly impact user satisfaction levels and system reliability. Many development teams utilize non-functional testing to determine the readiness of a project to enter production. By checking the software’s resilience and effectiveness in real-world conditions, teams uncover potential issues that may have flown under the radar during functional testing. Ultimately, this allows them to deliver higher-quality software.
Key Aspects Evaluated
Non-functional testing focuses on evaluating software system attributes that influence performance and usability instead of specific functionalities or behaviors. It ensures that systems meet the qualitative aspects of user requirements and operational environments.
For instance, scalability testing checks an app’s ability to handle fluctuating user demands. Compatibility testing assesses the app across various platforms and devices. Security tests evaluate data protection features and mechanisms. Encompassing a wide variety of types of testing, non-functional testing ensures that teams release software that’s user-friendly, robust, and dependable in various conditions.
Types of Non-Functional Tests
Non-functional testing focuses on qualities like compatibility, availability, and disaster recovery testing techniques. It covers various testing approaches as well.
Performance Testing
Performance testing evaluates the stability and efficiency of software under different conditions. Some of the main categories of performance testing include:
- Load testing assesses the behavior of a system under expected user loads.
- Stress testing helps teams determine the software’s breaking point by pushing it beyond normal operational capacity.
- Endurance testing verifies the system’s long-term stability and consistent performance by subjecting it to extended operations.
Usability Testing
Usability testing verifies and evaluates an application’s user-friendliness to ensure that it’s both intuitive and accessible for end-users. One of the most common methods of usability testing is A/B testing, which involves comparing two versions of a user interface to determine the best-performing option. Heuristic evaluations, another popular method, involve evaluations of the software against established usability principles to find areas of improvement.
Scalability Testing
The goal of scalability testing is to determine if an application can scale up or down to accommodate fluctuating demand levels. It ensures that as data volume or user numbers grow, the software can handle the added load without degradations in performance levels. This ensures that the software has the ability to handle continual growth while remaining functional, stable, and responsive under various conditions.
Security Testing
Security testing involves utilizing various techniques to ensure an app has robust data protection. This helps protect the system against data breaches and cyberattacks.
Security testing techniques include:
- Vulnerability scanning: Identified security weaknesses.
- Penetration testing: Simulates attacks to assess a system’s defenses.
Security tests safeguard software from unauthorized access to data and user information, ensuring confidentiality and integrity.
Reliability & Availability Testing
Reliability and availability testing verify that the software operates without interruptions, maintaining high uptime and resilience to faults. These tests confirm smooth functionality over time and under varying conditions, helping sustain user confidence in the app and guaranteeing dependability.
Compatibility Testing
In compatibility testing, development teams test software functionality across different operating systems, devices, and browsers. This verifies that the software is hardware-agnostic and remains user-friendly and effective under various operational conditions. Compatibility testing helps create a consistent user experience across different hardware and software systems.
Disaster Recovery Testing
This type of testing evaluates a system’s ability to recover from catastrophic disasters or failures. By simulating various disaster scenarios, testers verify that the planned recovery procedures are effective. They also assess how quickly data can be restored to minimize downtime and protect critical business functions.
Tools for Non-Functional Tests
Development teams have many options of tools for each type of non-functional testing.
Tools for Performance Testing
Tools help with assessing how well an app or software handles stress and high loads based on performance metrics. JMeter is one of the most popular tools for this task. It’s an open-source and highly customizable tool for testing web apps. NeoLad is a favorite tool for testing web and mobile app performance under high demand, with fast and accurate results in agile development environments. LoadRunner is a favorite due to its ability to simulate thousands of concurrent users.
Tools for Security Testing
Security testing tools assist testers in identifying vulnerabilities in their software. OWASP ZAP is a go-to choice for scanning web apps to reveal security issues. Wireshark assists with analyzing network protocols to gain insights into areas of an app with the potential for a breach through active network monitoring. Nessus prioritizes security risks after vulnerability scanning and offers extensive configuration options for enhanced customization.
Tools for Usability Testing
Tools for usability tests assist with optimizing the user experience and interface of the system. Crazy Egg, for example, offers heatmaps and visitor insights to help teams better understand user engagement. Many teams use Hotjar in their applications to collect user recordings of sessions, data, and interactions to flesh out necessary usability improvements. Optimizely, meanwhile, is a great choice for determining the best-performing options or elements through A/B testing.
Importance of Non-Functional Tests in SDLC
Testing the non-functional aspects of software is a vital part of the software development lifecycle. By focusing on the broader aspects of software, these tests help teams guarantee that their end products are as robust, secure, and user-friendly as they are functional. Identifying and addressing potential problem areas early on in the SDLC reduces failure risks while leading to greater user satisfaction and retention rates.
Process of Non-Functional Testing
Non-functional testing follows a cyclical pattern, similar to other types of testing.
#1 Requirement Analysis
Non-functional testing begins with determining the non-functional software aspects and requirements to analyze. The purpose of this step is to understand user expectations regarding usability, performance, security, and other non-functional qualities.
This initial phase involves gathering and refining these requirements with stakeholders. It also includes prioritizing non-functional requirements and determining necessary standards and benchmarks. For instance, teams building a banking app may want to prioritize security over aesthetic elements to protect user data.
#2 Planning and Design
The test plan and design phase involves selecting the appropriate tools and techniques for the specific software being tested. For example, teams employ JMeter to test app performance and Nessus for vulnerability testing. Creating a testing environment as a replication of the actual production environment is a crucial aspect of the process. This ensures that the test results are accurate and reflect real-world conditions to help teams understand how the app performs in typical scenarios.
#3 Test Execution
After finalizing the designs, teams then execute the test plans to assess the non-functional aspects of the software. This includes security scans, usability assessments, and load tests. Testers observe and monitor the software’s behavior and the selected tools for the testing to gather the most detailed data possible. This information provides highly valuable insights to help teams optimize the software, such as areas causing performance bottlenecks and security vulnerabilities.
#4 Results Analysis
After completing all necessary non-functional tests, testers compile the data from each source (including the tests themselves and results from various tools) to build a detailed report. This comprehensive report of the software’s non-functional performance should include a comparative analysis of the results against predefined benchmarks and standards. In building this, testers provide development teams and stakeholders with a list of areas and components that require adjustments or optimization.
#5 Reporting and Feedback
Using the data compiled in the previous step, testers create a comprehensive report on the findings of the non-functional tests. This report includes highlights of both the app’s strengths and areas in need of improvement. The data should be structured in a clear, actionable, and prioritized manner to outline the next steps. Testers then send the report to the developers to establish a feedback loop and ensure prompt action.
#6 Optimization and Retesting
The developers then implement the necessary changes based on the test results and feedback. After finishing the modifications, testers then re-test the software to ensure that all problem areas have been resolved and that no new issues have been introduced.
Best Practices
Following the best practices for non-functional testing better ensures that teams produce the highest quality software possible.
Clear Definition of Objectives
- Setting Clear Benchmarks: Teams should define measurable benchmarks for each non-functional testing area before starting. One example of a benchmark could be determining that a website shouldn’t take more than five seconds to load.
- Understanding User Expectations: Active engagement with stakeholders and end-users facilitates a better understanding of the expectations of the software. This information enables the team to create more accurate real-world usage scenarios and understand user needs.
Realistic Test Environments
- Mimicking Production: The testing environment must closely reflect or mimic the production setting. Discrepancies between the two environments could result in misleading testing outcomes.
- Frequent Environment Reviews: Teams must regularly review and update the testing environment to incorporate changes made in production, such as hardware modifications and software updates.
Comprehensive Test Coverage
- Cover All Non-Functional Aspects: Testers shouldn’t focus on only a single aspect of non-functional testing. Instead, they must aim to cover all relevant and crucial non-functional areas for a holistic testing approach.
- Use Varied Test Scenarios: Tests should be designed to cover scenarios ranging from the best to the worst-case scenario. This more accurately gauges the responsiveness and adaptability of the software.
Continuous Monitoring
- Utilize Monitoring Tools: Real-time monitoring tools for testing empower teams to immediately identify and address issues, preventing bottlenecks, vulnerabilities, and other problems. These tools also help ensure that the software meets various security and performance standards under different conditions.
Regular Reviews and Updates
- Periodic Test Review: Non-functional requirements evolve alongside software. To keep up with new releases and current needs, teams should regularly review and refresh testing benchmarks and scenarios.
- Staying Updated on Testing Trends: As non-functional testing continuously advances, it’s important for development teams to stay updated on new tools, techniques, and best practices. This keeps tests (and testers) both effective and efficient.
Collaboration and Communication
- Engage All Relevant Teams: The non-functional testing process should include testers, developers, system administrators, stakeholders, project managers, and end-users. These diverse perspectives provide more comprehensive insights and allow teams to create better tests.
- Promote Open Communication: Teams should establish a supportive environment of open feedback, suggestions, and findings for more innovative solutions through collective problem-solving.
Conclusion
Non-functional testing is an important complement to functional testing. By focusing on operational aspects of software, non-functional tests play a crucial role in assessing areas of the app that impact user experience. These tests ensure your software is not only technically sound but also user-friendly and able to handle a variety of use cases. Non-functional testing is a critical step in delivering comprehensive, high-quality software that meets relevant standards and exceeds user expectations.
FAQ
What differentiates non-functional from functional testing?
Functional testing verifies that specific software functionalities operate as intended. Non-functional testing involves evaluating broader attributes of a system, such as security, usability, scalability, and performance.
How often should non-functional testing be conducted?
Teams should conduct non-functional testing regularly, particularly after updates and feedback loops. They should perform testing continuously in CI/CD environments. It’s also important to conduct applicable milestone-specific evaluations when necessary, such as in the event of a new feature release.
How does non-functional testing differ from integration testing?
Integration testing verifies that components are interacting correctly, while non-functional testing ensures that the integrated systems meet broader standards including performance and reliability. Both testing procedures are essential for creating robust software systems.
