Software Requirement Specification

 Requirement specification is a description of a system that is to be developed, description of the system include user and system requirement.

User requirements are functional and non functional. System requirement is used by engineers for the system design. User requirements are written in natural language, simple table, form and understanding diagram that is easy to use. You should not use structure notation, software jargon that is difficult to understand. Software requirement specify that what a system services provided and what is not provided. Care full assessment of requirement can help in design. Software requirement specification help in design, estimation of product cost and risk arise in development, and should provide complete specification of the entire system.

To achieve the thorough understanding of the product, we have to communicate continuously with project team and customer until the completion of the project. Software requirement specification is a communication tool between end user and designer. Software requirement specification help in describing the scope of the work, providing navigation aids, document structure etc to software designer, linking features to customer requirement and facilitate reviews, providing framework for testing uses cases (primary and secondary),  Providing a platform for refinement.

In requirement document user requirement are written in natural language enlarge by suitable diagram and table. System requirement are also written in natural language but based on other notation such as form, graphical system model and mathematical system models. Notations that can be used for system requirement are

Natural language sentences

Structured natural language

Design description language

Graphical notation

Natural language specification:-

    Natural language is most widely used to specify system and software requirement. Natural language is used in the beginning of software engineering. It is expressive, universal and easy to understand it also ambiguous and vague.

Structured specification:-

                                         In structured specification all requirement are written in standard way where the freedom of the writer is limited. It used templates to specify system requirement. It uses the programming language to show alternatives and highlight important points using different fonts.

               Software requirement specification is a one of deliverable data item description or organization mandated content.

In software requirement specification process we determine the purpose of the system, overall description of the product, end user characteristics, interface of the system, user interface, hardware interface, software interface, communication interface, operation of the system and constrains on operation and design, product functions, performance and functional requirements, reliability, availability, maintainability and flexibility of the purposed system and use standards rule.