Although, the majority of testers understand the difference between functional testing solutions and usability testing services. However, it is actually something that can somewhat stump many professionals in the SQA industry. That’s an established fact that both play a pivotal role in the testing process, though at the same time, it is essential to know the difference between the two from technical as well as business perspective.

To differentiate the two, let’s begin with understanding these two individuals.

Functional testing solutions are implemented to ensure that the product or application under scrutiny behaves in accordance with the functional requirements. However, this does not include design principles. This involves a series of tests that are performed to ensure a feature-by-feature validation of behavior, by means of a wide range of normal and wrong input data.

Usability testing emphasizes on customer experience and acceptance and how well can they use the product to complete the required task.  Usability testing examines all landscapes of the usability of a product, focusing on the overall structure, navigational flow, even layout of elements on a page, content clarity, as well as overall behavior.

Is there a relationship between functional and usability testing?

In sequence, usability testing is performed after functional testing after functionality issues are resolved.

Executing usability testing on functionally-flawed products only uncovers functional problems that lead to hindrance for the customers struggling with bugs and defects when using the product.  It deters the customers and negatively effects their perception as well as feedback, and it nullifies the usability aspect of the results.

Functional as well as usability testing require different outlook and approach from the person testing. Preferably, it’s best to be performed by someone other than the ones involved in the development of the product to avoid biasedness.

For functional testing, this is the attitude you need:

“Is this product able to fulfill my need?”

“Is it performing as it promises?”

Whereas, Usability testing if more focused on the ‘usability’ element rather than ‘testing’. For usability testing, you need this attitude:

“Am I able to do what I need to do with this app?”

In usability testing, participants need to complete a number of important tasks that users of a product expect to be able to accomplish using the product.  After each task is complete, feedback is gathered from the users related to the product. This feedback helps to evaluate the application and see if it is a success or a fail, and check what areas require improvements.

This information collectively helps in determining the ‘why’ element behind certain usability faults and hindrances. Moreover, the value you get from this increases when the testing is performed by a team of carefully-selected users who match the target audience.

Even though these testing types are related, the differences between functional testing and usability testing are understandable and significant to the testing process. Here’s a simple way to visualize the difference between functional testing and usability testing: functional testing evaluates whether or not the product functions as expected, whereas usability testing focuses on whether or not the end-user is able to easily access those functions and use the product successfully.