What is requirements engineering process?

A requirements engineering process is a structured set of activities that is done to develop, validate and maintain a system requirements document. Activities involved in requirements engineering process are requirements elicitation, requirements analysis and negotiation, requirements documentation and requirements validation.

Requirements elicitation.

The system requirements are known by consulting the end users, project managers, from domain knowledge, from existing system documentation and other relevant sources. Other names for requirements elicitation are requirements acquisition or requirements discovery.

Requirements Analysis .

There requirements are analyzed for necessity of the requirements, consistency and completeness checking and whether the requirements are feasible in terms of budget and time.

Requirements Negotiation

Problematic requirements are identified and discussed to solve it. Stakeholders and software developers finally agree to make the necessary changes and finalize with set of agreed requirements.

Requirements Documentation.

The agreed requirements are documented using natural language which is understandable by all stakeholders. Supporting diagrams such use case diagrams or sequence diagrams are incorporated in the document to give higher level of details.

Requirements Validation

The agreed requirements are checked for consistency and completeness to detect any problem is the requirements before it used to develop the system. This activity will help to minimize cost of the fixing errors in the early stage of system development.

Reference : Requirements Engineering, Gerald Kotonya and Ian Sommerville.

Requirements Document (Software Requirements Specifications)

Requirements document or also know as Software Requirements Specification is official statement of the system requirements for end users, software developers, project managers and customers.

It is written using natural language which is easily understood by all readers. It should describe the following.

1. The purpose of the software.
2. Standard conventions used in the requirements document.
3. Intended user and their level of technical competencies
4. Project scope, it's goal; and objectives.
5. Overall description to the software.
6. Brief description of the software features.
7. It's intended operating environments
8. Design and system constraints under which the system must operate.
9. User documentations that should be delivered with the project.
10. Functional requirements of the software.
11. Non functional requirements such as performance, safety, security and reliability requirements.
12. And other external interface requirements such as software requirements, hardware requirements and communication requirements.

To support the requirements document you could use use case diagrams and sequence diagrams to have higher level of details.

Please click here, to get requirements document template.