User Requirements (UR) definition

• The UR phase is the problem definition phase in which the scope of the software is clearly specified by the users in cooperation with the developer’s teams of software engineers, hardware engineers, and managers.
• In the UR phase, the operational environment of the software is determined.
• The users requirements are captured and documented in a User Requirements Doc (URD).
• The review of the User Requirements Doc is performed by the same teams who have already worked on software specifications in the UR phase.
  

Software Requirements (SR) specification

• The SR phase is the software requirements analysis and specification phase.
• A logical model of the software is produced (using Structured analysis or Object-Oriented Analysis) and used to analyze the completeness, consistency, and testability of the requirements
• Software Requirements Document (SRD) is produced and is formally reviewed (SR/R) by the users, software engineers, hardware engineers, and managers concerned.
  

Architectural Design (AD) specification

• The Architecture Design (AD) phase deals with the construction of what is termed as “the physical model” of the software. It defines the architecture or structure of the software in terms of components or modules and their interfaces.
• The software components as well as the data flow and control flow between them are defined.
• The deliverable produced in this phase is the Architectural Design Document (ADD). The ADD is again formally reviewed (AD/R) by the same teams mentioned above.
• The activities of the DD phase include module design, coding, unit testing, integration testing and system testing.
• A Detailed Design Document (DDD) and the Software User Manual (SUM) are produced concurrently with coding and testing
  Unit, integration, and system testing is performed according to verification plans established in the SR and AD
• The code, DDD, and SUM documents are reviewed in the formal Detailed Design Review (DD/R) by software engineers and the management concerned

Detailed Design (DD) and production of the code

• The activities of the DD phase include module design, coding, unit testing, integration testing and system testing.
• A Detailed Design Document (DDD) and the Software User Manual (SUM) are produced concurrently with coding and testing
• Unit, integration, and system testing is performed according to verification plans established in the SR and AD
• The code, DDD, and SUM documents are reviewed in the formal Detailed Design Review (DD/R) by software engineers and the management concerned
  

Transfer (TR) of software to operation

• The TR phase includes the installation and the provisional acceptance testing activities to establish that the software fulfils the requirements
• A Software Transfer document (STD) is produced which contains the description of the activities performed and the transfer of the software to the operation team.
  

Operations and Maintenance (OM)

• In the OM phase, the software is monitored for enough time to establish the final acceptance