Life cycle and processes
The needs modeling that has been discussed in this chapter is carried out during a typical development life cycle. With this in mind, consider the following development life cycle model, which was introduced in Chapter 4, Life Cycles.
Figure 6.27 – Example development life cycle model
The diagram in Figure 6.27 shows an example development life cycle that is visualized using a SysML sequence diagram. The stages in this life cycle model are those from ISO 15288 and the execution of the stages is a simple linear sequence.
The obvious place for the needs modeling to occur is during the first stage in the diagram, Concept. This is where the majority of the needs modeling will take place, but the needs will also be revisited throughout the entire life cycle as needs will change as time goes on and, very importantly, some of the contexts associated with the needs may change.
The approach to needs modeling must map onto best practice...
