PxFAQ: What are the services we *need*? (posted by Fabien Villard)
Related questions:
- How to find them?
- How to assert that they are the right ones?
- How to respect the decoupling principle?
By giving clear procedures to deduce services from business inputs, Praxeme solves the problem of finding the right services in the only available way: changing intuition only procedures to analytic thinking. By structuring precisely the considered system in separated yet linked aspects, Praxeme guaranties that the separation of concerns and the decoupling principles are respected. Moreover, the Enterprise System Topology (EST, the collection of the height aspects) guaranties that none of the important domains are forgotten and that the models are complete enough to prove that the system respects the primitive needs and goals expressed by the business and the regulations.
Services start their life in the Logical Aspect as an architectural decision. SOA in this matter must be considered as an architectural style. It is obviously independent from technologies because services can be implemented in a lot of them (POJO, J2EEE, .NET, php, Rubis/Rails, and even REST (if we admit to distort the initial REST concepts)…) and it is not very wise to have to change services when we want to change technologies that evolve a lot faster than the services themselves. In the logical aspect, services are built by deriving upstream aspects. This means that far from guessing the collection of services, Praxeme gives rules to deduce services from previous work, either inner services (the core stratum) or organizational ones (the organization stratum). Note that this does not imply that the process is completely automated. Logical model building still needs human decisions and innovations may also reside here.
