1.2.3 Software Development

• Feasibility • Requirements • Analysis and design • Implementation • Testing • Evaluation • Maintenance

• Establishes whether or not the project can be done Considers factors of the project e.g. technical, economic, legal and political

• A specific feature of the new system and recorded in a document called requirement specification

• Interface: how the user interact with it • Functional: what the system will do • Performance: how well/fast will the system respond

• The process of taking the requirements of a new system and deciding what the system will look like, how will it store data • Design can only go ahead once the requirements specification has been completed • Each requirement needs to be incorporated into the design

• Derives its name from cascading effect from one phase to another • Each phase has a well-defined start and end point with identifiable deliverables

• Simplicity makes it easy to manage • Everyone on the project is very clear on the responsibilities at each stage • Clear deliverables • Easy to see if a project is running to schedule

• Carries a lot of risk • The user doesn’t get to see the product for the first time until the project is near its end • Misunderstanding requirements can lead to a project that is not easy to fix • Requirements must be very well understood so this model is not suitable for complex projects

• Risk-driven development methodology • More of a guide for development teams, allowing them to adopt element of one or more other methodologies • Better thought of as a process model generator, where decisions on the software development methodology are made based on the risk identified

• Risk management is at the heart of this model • Excellent for projects that contain a high level of risk

• Complex nature of risk analysis increases costs - risk management is a highly specialised skill • If risk analysis is done badly, the project suffers

• Involves producing successive prototypes of the software until a final version is produced and approved