An emerging software engineering methodology

The evolutionary approach we have sketched in this paper can be characterized by the following principles:

• System parts are decoupled by separating computation from coordination.

• A process-oriented, formal, method describes the coordination of components.

• A common intermediate representation standardizes the exchange of information between components.

• Testing and debugging of components is standardized.

• A wide variety of software engineering techniques is used to construct components. Where applicable, we use formal specifications to design and prototype components.

• Each component of a system may be in a different phase of its evolutionary life-cycle and may be replaced anytime.

• The creation of distributed, heterogeneous, systems is accommodated.

We have illustrated all these principles with techniques and examples from our own experience. The same principles can, however, also be applied based on other technology.