Business requirements are typically classified into three business requirements categories. The categories are functional requirements, non-functional requirements and design constraints. The definition of these categories are:
Functional Requirements:
Describe the system features or things the system must do to support the end user’s business responsibilities. i.e. The system shall allow the ATM User to deposit funds into their individual bank account.
Non-Functional Requirements:
Describe properties the system must have (e.g. performance, availability, accessibility). What are the qualities the system needs to have for the user? i.e. The system shall provide an ATM transaction response time of 5 seconds.
There are four categories of non-functional requirements:
- Usability – ease with which a user can learn to operate and usability design standards
- Reliability – availability of the system, nightly backup, logs, nightly backup
- Performance – maximum users, response time
- Supportability – Error messages, error logs
Design Constraints:
Limits the development in some way. Such as, defining an operating system the system must run on, or defining which programming language must be used to implement the system. i.e. The ATM must have touch pad screens.
To learn more about how to elicit and write effective business requirements register for Pierson’s Virtual Business Requirements Gathering & Writing Class.