Object-Oriented Analysis

Analysis emphasizes an investigation and understanding of the problem domain and requirements, rather than a solution. Read this section to learn more about some of the terms and concepts related to requirements and their types. These terms can seem ambiguous at first, but we will quickly learn how they relate to one another.

2. Requirement Specification

Requirements documentation is a very important activity, which is written after the requirements elicitation/gathering and analysis, i.e. requirement capture and analysis phase of the software development process. This is the way to represent requirements in a consistent format. The requirements document is called the Software Requirements Specification (SRS). The SRS is a specification for a particular software product, program, or set of programs that perform certain functions in a specific environment. 

The requirements specification is a description of needs or desires for a product. It is the official statement of what is required of the system developer. The requirements must be described unambiguously and in a form that clearly communicates to the client and to the development team members.

It is not a design document and it must state what to be done rather than how it is done. It must be in a form which can be taken as the starting point for the software development. A specification language is often used. Graphical notations are often also used to describe the requirement specification. 

It is recommended that the requirements specification at least include the following information:

i. An overview of the project 

ii. Goals/purpose 

iii. Glossary – definition all relevant terms 

iv. System functions

      • System functional requirements, these are functional requirements 
      • System attributes (non-functional requirements) 

v. Use cases – narrative descriptions of the domain processes 

vi. Conceptual model – a model of important concepts and their relationships in the application domain.

These are typically produced through gathering and digesting 

i. Documented information such as the client's statements about their needs, preliminary investigation report, and electronic documents, 

ii. interview results, 

iii. requirements definition meetings, and so on