Functional and Non- functional testing: checklist and features

There are but two distinct approaches to take when it comes to the testing of software applications, namely, functional testing and non-functional testing.

A well-thought-out plan or strategy involves both functional as well as nonfunctional testing, given that they are both important aspects it is also equally important to note that they serve distinct purposes. Here is a short walkthrough of both methods that will aid you in choosing between them.

Functional testing:

Functional testing is essentially hinged on the concept of testing out every individual component of the application with the hopes of smooth running. This method isn’t particularly focused on the source code of the application but rather on the black box testing aspect of it. This step involves meticulously testing out the functionality of the software by plugging in appropriate input variables and corroborating the output of the same. It is followed by comparing the expected result to the actual result and fixing all and any discrepancies that occur. Other things that are paid attention to are APIs, databases, user interfaces, client applications, and server applications. The test can either be executed manually or even in an automated manner.

The aspects that are put to test with this method are as follows: major functionality, error validation, unit testing, smoke testing, sanity testing, integration testing, regression testing, installation testing, API testing, and user acceptance testing

Non Functional testing:

Nonfunctional testing is an approach to software testing that is hinged on ascertaining aspects such as usability, performance,  reliability as well as scalability of the software in question. This checks aspect such as readiness of the whole software and how many people can use it simultaneously. There is no particular hierarchy between the two methods of testing, but which one is better suited for the specific software in question? The aspects that are put to test with this method are as follows: security, usability, scalability, interoperability, efficiency, and flexibility.

Some of the key differences that illustrate the qualities of the two forms of testing and also serve as a checklist are as follows:

As the name suggests functional testing refers to the evaluation of the software’s features whereas its counterpart evaluates attributes that are not functional by nature which are, but are not limited to, usability, reliability, and performance. The execution of functional testing can be tested manually or in an automated manner but the execution of non-functional testing is almost exclusively automated (for best results). The goal of functional testing is to satisfy the requirements of the customer whereas the goal of non-functional testing is to meet the customer’s expectations. Functional testing is done in order to check the actions performed by the software whereas non-functional testing is done in order to evaluate the performance of the same software

Functional aspects and testing help in gauging what exactly the deliverable is but nonfunctional aspects are an accurate measure of how the same deliverable works. The functional testing almost always with very little room for exception precedes the nonfunctional testing.

To further illustrate the differences between the two here is a list of parameters that serve as a point of differentiation and also as a checklist are:

Execution

Objective

Usage

Manual testing

Functionality

Testing types

Focus Area

Requirement

Example test case

Both methods also have different levels of testing, namely, alpha testing and beta testing.

On a concluding note, we would like to mention that most apps and online services lose up to 95% of their users in the first three months, what we can gauge from this is that apart from employing these two testing methods a good strategy must also be put in place for maximum efficiency.

It is also worth mentioning that there is no particular hierarchy when it comes to these testing mechanisms, no one method is better or more important than the other on the contrary both the methods unify to ensure a better user experience.