because software solutions can be automatically derived from models by “technology independence”. “Domain model” is modeling the actual existence of a domain. It is called “Computation Independent Model (CIM)”. “Logical system model” is modeling a service with domain model, in which the components of a system interact with each other. It is called “Platform Independent Model (PIM)” “Implementation model” is modeling a specified system which logical system model can work with a specified technology and platform, which examples are Linux, Web application and SQL database. It is called “Platform Specific Model (PSM)”. Those 5 processes are encapsulated and operated in parallel.