“In a software development lifecycle (SDLC), every developed application needs to go through multiple levels of testing and functional testing is one of them. This process will ensure quality assurance and quality control through every step of the development and testing processes. Functional requirements of the program, whether they match the specifications or not are tested through this method.”, said Bahaa Al Zubaidi.

1. Different Phases of Functional Testing
“In a software development lifecycle (SDLC), every developed application needs to go
through multiple levels of testing and functional testing is one of them. This process will
ensure quality assurance and quality control through every step of the development and
testing processes. Functional requirements of the program, whether they match the
specifications or not are tested through this method.”, said Bahaa Al Zubaidi.
The extensive testing mechanisms that you will deploy as per your IT partner’s
strategies will help you to identify and fix potential failures and pain points. Hence,
before the final application is handed over to the end customers, extensive functional
testing will eliminate the issues, and you will have happy customers.
Functional testing is imperative in Agile methodology. During every sprint, it will be
conducted. While the programmers are writing the codes, the functional testers perform
these tests to ensure that existing functionalities, features, and codes are not affected
by the newly patched changes.
Whereas the waterfall model of software development depends more on code and unit
testing, integration testing, system testing, and acceptance testing.
1. Sanity Testing- This surface-level test is performed to verify that all the commands
and functions built into the program are always working at an expected threshold term.
2. Smoke Testing- To assess if the critical features of the software program are working
properly.
3. Regression Testing- This test is extremely crucial as it involves testing to ensure that
the previous functionality is working fine. The new codes that have been introduced to
enable another function do not have any conflicts with the existing codes.
4. Integration Testing- After the unit testing, this is done to check the proper functionality
between surrounding components.
5. Usability Testing- It is done to ensure that the developed program meets the
requirements of the end customer.
To ensure optimum service delivery, there is another type of testing known as
performance testing. Performance testing is an important step in the agile framework.
This process is used for testing the speed and response time of a software application
under different circumstances. While doing the performance testing, the scalability,
reliability, and resource usage of a software application too is tested.

2. Performance testing is done at the end of every sprint (agile framework) and before
accepting the solution. However, it is done only at the end of the development process
in the waterfall model. Even though Agile has taken over the waterfall approach in most
modern software development practices, many companies still depend on the waterfall
model.
Different Phases of Performance Testing
Performance testing happens multiple times during the sprint to ensure that there are no
performance bottlenecks. It is not meant to find bugs. According to Bahaa Al Zubaidi,
Bug fixing is done during the functional verification testing (FVT), bug-fixing, and QA
process.
Types of Performance Testing
1. Load testing/Spike Testing- The purpose of load testing is to determine the website or
application’s performance under different circumstances. It intends to determine what
happens when there is normal traffic to the website/application and when there are
extremely high traffic conditions. It needs to establish at what point the
website/application will crash and take necessary precautions accordingly.
2. Stress Testing- The application or website is pushed to the breaking point to check its
recovery and response time.
3. Scalability Testing- It is done to check how an application performs at the minimum
and maximum load levels. This is done to ensure that new customers can be enrolled in
the system without making any changes to the website. For example, a telecom
provider, or financial institution with a target of increasing its customer database needs
to ensure that its application performs well even after more customers join the network.
4. Volume Testing/Flood Testing- Volume testing is mandatory to check how the
website/application performs when multiple transactions happen simultaneously.
Typically, on a payday, the volume of transactions on banking sites increases.
There are many other methodologies that are adopted in the SDLC in an agile
framework which we are not discussing here. However, in order to ensure optimum
service delivery, it is important to follow all the steps diligently.
Thank you for your interest in Bahaa Al Zubaidi blogs.
Bahaa Al Zubaidi