Methodology for object-oriented system architecture development

The classical approach to developing system architectures starts with the Functional Flow Diagrams (FFD). The FFDs are decomposed into the lowest level necessary to produce the functional architecture. The functional architecture is then organized into logical pieces to produce the physical architecture. The current object-oriented approach to developing the system architecture still starts with the FFDs. But the FFDs are basically a structured methodology which is diametrically opposed to the object-oriented paradigm. Structured methodology focuses on the functions or processes in the system while the object-oriented methodology is based on the objects or nouns in the system. Functions are actions or verbs. Objects are nouns, i.e. person, place, or thing. Thus the structured approach is the opposite of the object-oriented approach. This paper formulates a wholly object-oriented (OO) approach to system architecture development. The advantages of an OO approach to system architecture are the same as the advantages of OO to software architecture, namely the tight coupling and encapsulation within an object and the loose coupling between objects. This type of architecture is well-suited to systems of systems which must be flexible enough to add and remove systems.