Requirement Engineering 是 Process

The software requirements are description of features and functionalities of the target system. Requirements convey the expectations of users from the software product. The requirements can be obvious or hidden, known or unknown, expected or unexpected from client’s point of view.

Requirement Engineering

• 是 gather, analyze and document 需求的process
• 目标是 ‘System Requirements Specification’

It is a four step process, which includes –

• Feasibility Study
• Requirement Gathering
• Software Requirement Specification
• Software Requirement Validation

Software Requirement Specification

SRS is a document created by system analyst after the requirements are collected from various stakeholders.

SRS defines how the intended software will interact with hardware, external interfaces, speed of operation, response time of system, portability of software across various platforms, maintainability, speed of recovery after crashing, Security, Quality, Limitations etc.

The requirements received from client are written in natural language. It is the responsibility of system analyst to document the requirements in technical language so that they can be comprehended and useful by the software development team.

SRS should come up with following features:

• User Requirements are expressed in natural language.
• Technical requirements are expressed in structured language, which is used inside the organization.
• Design description should be written in Pseudo code.
• Format of Forms and GUI screen prints.
• Conditional and mathematical notations for DFDs etc.

Software Requirement Validation

After requirement specifications are developed, the requirements mentioned in this document are validated. User might ask for illegal, impractical solution or experts may interpret the requirements incorrectly. This results in huge increase in cost if not nipped in the bud. Requirements can be checked against following conditions -

• If they can be practically implemented
• If they are valid and as per functionality and domain of software
• If there are any ambiguities
• If they are complete
• If they can be demonstrated

https://www.tutorialspoint.com/software_engineering/software_requirements.htm