Functional testing

In software development, functional testing is performed to ensure that software works correctly. In functional tests, testers identify what an application is supposed to do and run a series of tests to make sure that it performs as expected. The ultimate objective of functional testing is to ensure that a piece of software meets the customer’s specific requirements for functionality.


Tricentis Staff

Various contributors

Date: Aug. 06, 2021

The steps involved in functional testing include:

  1. Using test data to identify inputs
  2. Identifying what the expected outcome should be based on inputs
  3. Running test cases with inputs
  4. Comparing the expected results to actual results

Non-functional testing

In addition to functional testing, quality assurance (QA) teams will perform non-functional tests designed to review and verify other aspects of a software application. Non-functional testing may evaluate usability, reliability, scalability, compliance, performance under different loads, and other criteria that are not directly related to business function.

Where functional testing is intended to ensure that software meets the requirements of an organization, non-functional software testing is designed to ensure that software meets the expectation of users. Most non-functional tests are automated.

Types of functional testing

The most common types of functional tests include:

  • Unit tests: unit tests evaluate each individual unit and module code to make sure they perform appropriately
  • Component tests: these tests validate objects or parts of the software separately
  • Smoke tests: a smoke test, which is a type of regression test, evaluates software in a non-comprehensive manner to ensure the software works well enough (or is not riddled with too many issues) to move on to additional tests. Also known as a build verification test
  • Integration tests: integration tests examine multiple individual units of the software as a group to make sure they interact appropriately
  • Regression tests: regression testing ensures that that code changes have not had a negative effect on the functionality of the software
  • Sanity tests: sanity tests, which are a type of regression test, evaluate the software in a non-comprehensive manner after code changes have been made to ensure the changes didn’t create any serious issues. Typically performed after smoke tests
  • System tests: system tests are performed to ensure that all system elements are working as intended. They also verify system performance and functionality and are typically performed by testers who have not played a role in developing the program
  • User acceptance tests: Often the last step before software goes live, user acceptance tests make sure the software meets user needs. These tests are usually performed by end users and measure how well the application performs in typical scenarios

Methods of functional testing

Regardless of what type of functional test is performed, there are several methods and QA testing tools that may be employed to execute tests and gather data.

  • Manual scripted testing is typically used when very complex tests must be run, when adhering to strict regulations that require documentation, and when testing legacy systems doesn’t easily support automated tests.
  • Exploratory testing is a form of manual testing where testers set out to understand how the software works and then identify different tests to run based on that understanding. Since exploratory testing is not scripted, it typically mirrors how users will interact with the software in actual practice.
  • Automated testing can be used in a variety of scenarios to run tests more quickly and improve the accuracy of results.
  • Behavior-driven development (BDD) testing is a method that encourages collaboration between testers, developers, product owners, and others to create a shared understanding about requirements. BDD testing is focused on users and delivers high levels of efficiency and effectiveness in user experience testing.
  • Risk-based testing prioritizes tests for high-risk areas of software and mitigates risk by ensuring a high level of test coverage. Risk-based testing is often used to focus testing resources efficiently.

Challenges of functional testing

Managing functional testing can be extraordinarily complex, especially in an environment with multiple technologies. The challenges of conducting functional tests include:

  • Gathering clearly defined and complete requirements for each piece of software
  • Planning tests by identifying potential functional gaps
  • Developing a test strategy to complete tests within given deadlines, using appropriate resources, and ensuring optimum test coverage
  • Executing tests and ensuring that test plans accurately match the functionality to be measured
  • Managing defects uncovered by tests
  • Ensuring that reporting on defects is complete, clear, and consistent, and that severity and priority is accurately attributed
  • Reporting results of functional tests within a certain timeframe and in ways that make sense to each stakeholder
  • Gathering metrics to gauge the effectiveness and quality of the testing process

Solutions for automating functional testing

Tricentis Tosca simplifies functional testing by overcoming the barriers of legacy and conventional functional test automation methods. With innovative risk-based and model-based test automation approaches, Tricentis Tosca simplifies end-to-end regression testing for more than 160 technologies.

Tricentis Tosca provides Agile software testing teams and DevOps with:

  • Support for multiple testing methods. Use exploratory testing, manual testing, automated testing, and BI/data warehouse testing to test functional requirements
  • Control over the test suite. Plan tests, design test cases, manage and maintain test data, and gain insight into business risk
  • Sustainable test automation. Minimize test maintenance and maximize reuse so that rapid change won’t disrupt test automation
  • An easy-to-use interface. Create test cases by scanning, recognizing controls, or recording – all while still being business readable
  • Best-of-breed technology. Plug into continuous integration frameworks, use distributed execution, simulate missing systems, leverage APIs, connect with other tools, and provide advanced reporting and analytics
  • Integration with enterprise environments. Test cross browser, mobile, SAP and SAP Fiori, Java, .net, XML, JSON, REST, ServiceNow, and more
  • Tests aligned with business risks. Understand what tests and data are required to cover business risk. Change the focus of testing from “pass/fail” status to “Is the level of business risk in this software acceptable?”

Tricentis Staff

Various contributors

Date: Aug. 06, 2021


What is functional testing?

Functional testing is performed to ensure that software works the way it is supposed to and conforms with the requirements for the software as determined by the customer.

What are the benefits of functional testing?

Functional testing aims to ensure that software is free of defects and will satisfy the needs of the customer and end user. It checks that software functions as it is supposed to and works as expected. Functional testing is designed to improve the quality of the software and reduce the risk associated with the product.

What is non-functional testing?

Non-functional testing focuses on quality concerns that aren’t directly related to the functional requirements of software. Non-functional testing may verify the usability, compliance, performance, security, and scalability of an application. If functional testing is designed to ensure that software meets business requirements, non-functional testing is designed to ensure that software meets user expectations.

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