Functional and Non-functional Requirements

01 Nov 2023

Functional requirements are the requirements that describe the functionalities of the system elements. It may involve functional user requirements or functional system requirements. For example:

  • The operator shall be able to input the weather periods to the system to view the desired weather parameters within the particular periods.
  • The system shall be able to produce minimum, maximum and the average data of a particular weather parameter when it is requested by an operator.
  • The system shall provide the following weather parameters: temperature, pressure, wind speed & direction, rainfall, and humidity.

On the other hand non-functional requirements describe the system properties and constraints. Whereas these may not describe directly what the system should do or perform, instead they describe the standard of the objectives that the system should achieve. For example:

  • The weather system shall be ready by 31 November.
  • It shall not exceed the budget that has been stated in the MOU ($1.3 million).
  • System’s operational and location of remote station and central station shall not violate the current Government regulations of environment and
  • The weather sensors shall be able to be upgraded every 5 years.

[SMT]