What is Functional Testing and How to Run It?

The goal of quality assurance is to guarantee that the software works well. The “well” part implies that an application runs smoothly and all its features work as supposed. This latter aspect is an area of responsibility for functional testing. It can come in a form of manual software testing services or be automated.

Functional testing services are meant to verify the conformity of software requirements stated in documentation with the real characteristics. In other words, this is an “expectations vs reality” check. And if those two don’t match, a development team receives code back for further improvements.

There are two approaches that allow a QA company to determine if an app meets customer expectations. One of them implies testing based on requirements. We read functional specifications and use them as premises for writing tests. The other one is testing based on business scenarios. In this case, we learn how a system should behave and check its features from the perspective of business processes.

Why Do You Need Functional Testing?

So what is the role of functional testing in software testing? Just like any other type of QA inspection, it allows releasing software without critical bugs. It helps find answers three essential questions:

• Does this program even work?
• Does it work as everyone expected?
• Are there any unpredictable ways it can work?

By running functional tests, a QA team can verify that all features behave properly or, on the contrary, there are some points of concern. A list of issues can include missing functionality, UI errors, incorrect error conditions, etc. Here is a couple of peculiar things about functional testing:

• It provides a replica of a product in a live environment.
• It eliminates any assumptions about system behavior.
• It helps detect gaps in logic and features that don’t work as supposed.

Manual vs Automated Functional Testing

Test automation services, as always, helps reduce testing time and effort, but only if you find the right cases to automate and tools to use. Automating functional testing may be a complicated task, taking into account a large number of user scenarios.

One hundred percent functional automation is not achievable. For instance, regression and UI testing are often automated, while acceptance testing can be manual only. Besides, there are a variety of cases where manual input is the only way to check a feature. Manual functional testing is also a better solution when you have to mimic real-user behavior closely.

Our advice would be to use the combination of both, especially for long-term projects with a potential for scalability.

Checklists and Test Cases

To test software features, a QA engineer feeds an input to a system and examines the output. The result of this operation is more important than the way the processing occurs. A functional testing checklist always depends on project type and niche. It shouldn’t be a surprise: a mobile game app and a cloud solution for healthcare don’t have many features in common. Among the other things, a QA team usually pays attention to the following:

• User interface. It covers two aspects: whether visual elements (buttons, checkboxes, texts, etc.) are displayed correctly and whether they work correctly.
• Error conditions. Error codes and messages they return should match and be understandable. If something goes wrong, a user should understand what exactly has happened and what to do next.
• APIs. It is a check-up of the programming interfaces that focuses on business logic rather than the look or feel of an app.

Unlike features, step-by-step directions for functional test planning will be very much the same for diverse types of applications. A typical workflow looks like this:

1. Learn about expected software features and identify what functionality to check.
2. Create input values based on the software specifications and requirements.
3. Determine an expected output for every feature.
4. Execute test cases.
5. Compare actual and predetermined output.

Best Practices of Functional Testing

Start writing test cases early. This process can begin at the requirements analysis stage when all details regarding features are evident. The more time passes, the more likely you will need to find a person who can refresh the initial idea behind every functionality, especially in large-scale projects.

Consider using a traceability matrix. QA teams are not always involved in the earliest stages. To make sure no feature is overlooked, you can create an RTM – Requirement Traceability Matrix, a document that enhances functional testing services. Clients, developers, and QA engineers use a shared report to outline requirements and map test cases. You get a comprehensive textbook to use whenever you need to refresh your memory.

Prioritize features and test cases. Every app has money-making functionality – a value that makes users install it. It is the most frequently used part that drives the most attention, so it is reasonable to start with testing these core parts first. Supporting features and other perks can wait.

Act like a real user. Try not to become biased. Use an app as you’ve never seen it before. Be a researcher. Mimic user behavior closely to understand how an application satisfies your needs.

Tools for Functional Testing

The choice of a functional testing tool always depends on project requirements and specifications. Here are some of the most popular and commonly used solutions:

• Selenium – open-source software that supports many languages for writing scripts. Selenium functional testing is easy to run on Windows, macOS, and Linux against most modern browsers.
• Sahi – an open-source tool with extended opportunities in Pro version. It is browser and OS independent, easy to set up, and suitable for both traditional and Agile environments.
• IBM Rational Functional Tester – one of the top-popular tools that can mimic the actions of a human user and supports a variety of applications. It is available on subscription with a 30-day trial version. The scripts are in Java or basic.Net.
• test IO – a crowdtesting platform that lets you check all types of software under real-world conditions on a variety of devices and browsers.
• Cucumber – an open-source tool originally meant for Ruby testing that now supports a variety of languages. Cucumber functional testing is perfect for behavior-driven development.

Functional testing automation can be implemented using a dozen of other tools, like SoapUI, TestComplete, Ranorex Studio, Watir, etc.

Bottom Line

All tech products, despite their diversity and highlights, have something in common: software functional testing is a must for each. QA Madness team can run functional testing for your project, so you will be sure to release a product you’ve intended to. Contact us for more information anytime.