Software Testing - Functional Requirements
A software is always developed as per its functional, and non-functional requirements. Thus the requirement analysis is a very important step towards a successful development of a software. The requirements are of two types namely functional, and non-functional. There are many differences between functional, and non-functional requirements of a software.
Software Functional Requirements
The functional requirements are the specifications that the customers require as part of the basic features of the software. All these specifications need to be mandatorily implemented as a part of the software. They are represented in the form of inputs fed to the software, processing of the data, and outputs they generate. The functional requirements are given by the customers and are directly visible in the final software. However, the non-functional requirements cannot be physically detected on the software. The functional requirements define the features that are required to design the software, and the edge cases to validate them. The functional testing is done to validate the functional requirements of the software.
Software Non-Functional Requirements
The non-functional requirements are the quality parameters that the software should meet. The extent to which these parameters are implemented depend on the project to project. They are considered as the non-behavioural specifications of the software. The non-functional requirements touch upon factors such as flexibility, reliability, maintainability, portability, security, scalability, performance etc. The non-functional requirements include measurement of the minimum latency required to process requests. The non-functional is done to validate the non-functional requirements of the software.
Software Extended Requirements
The extended requirements are the nice to have requirements of the software, and are not mandatorily the part of it.
Functional Requirement Specifications
The following are the key fields, which should be part of the functional requirements specifications document −
- Purpose of the Document
- Scope
- Business Processes
- Functional Requirements
- Data and Integration
- Security Requirements
- Performance
- Data Migration & Conversion
Difference between Software Functional and Non-Functional Requirements
The difference between software functional and non-functional requirements are listed below −
| Sr.No. | Functional Requirements | Non-Functional Requirements |
|---|---|---|
| 1 | They describe a software, and its components. | They describe the quality factors of the software. |
| 2 | They explain what is expected from the software. | They explain how the software should satisfy the functional requirements of the software. |
| 3 | They come directly from the customers. | They come from the technical people namely developers, architects, technical leads etc. |
| 4 | They are the mandatory part of testing the software. | They are not the mandatory part of testing the software. |
| 5 | They are described by the use cases. | They are described by the quality parameters. |
| 6 | They are defined at each component of the software. | They are defined at the software level. |
| 7 | They validate the features of the software. | They validate the performance of the software. |
| 8 | The functional testing includes system testing, integration testing, end to end testing, API testing etc. | The non-functional testing includes performance testing, stress testing, security testing, reliability testing, usability testing etc. |
| 9 | They can be described very easily. | They can not be described very easily. |
| 10 | Examples − payment to be successful only if a valid payment information is available, allowing only valid users to log in etc. | Examples − response time to process a request is less than five seconds, the page load time should be of maximum three seconds etc. |
Conclusion
This concludes our comprehensive take on the tutorial on Software Functional Requirements. Weve started with describing what are the software functional requirements, what are the software non-functional requirements, what are the software extended requirements, and what are the differences between the software functional and non-functional requirements. This equips you with in-depth knowledge of Software Functional Requirements. It is wise to keep practicing what youve learned and exploring others relevant to Software Testing to deepen your understanding and expand your horizons.