Software lifecycle

The particular software lifecycle model adopted by ING is that of the ESA Software Engineering Standards. For convenience it is given here:

• User requirements definition, resulting in a User Requirements Document as a product.
• Software requirements definition, resulting in a Software Requirements Document as a product.
• Architectural design, resulting in an Architectural Design Document as a product.
• Detailed design and production, resulting in a Detailed Design Document, the software source code, the Software User Manual (or Manuals) as products.
• Transfer, resulting in the Software Transfer Document and Acceptance Test Report as products.
• Operations and maintenance

The first four stages in the software lifecycle are the development part of the lifecycle. It is by no means intended that the development process should be strictly a linear progression from one stage to the next. It is expected that throughout the development part of the lifecycle, minor changes to the products will be made as a result of an increasing understanding of the requirements and design issues. However, it is expected that all required documentation will be up to date and accurately represent the delivered software system once the transfer stage is reached.

The use of the ESA model of the software lifecycle during development is discussed in detail in SOF-STD-2, The ESA Software-Engineering Standards at the Royal Greenwich Observatory. The transfer phase is discussed in detail in SOF-STD-4, Testing and Delivery of Software for ING.