Ada 95 as a base to architect systems in O4S™

Abstract

Traditional “architecture” for buildings is studied to find what “architecture” should mean for complex information systems with a high software content. Different architectural qualities are presented and referenced to Ada 95-based work.

The system development O4S™ (Objects For Systems) is presented as a method that handles not only the information aspect of software and/or software, but complete systems including missions and operator's roles. In connection to O4S™, the Ada 95-inspired design language Odel is presented as a means to describe structure and behaviour of complex systems.

The concept of “architectural base” is introduced as a necessary base to architect and describe systems. It is shown how the architectural base for systems work can be connected to software standards:

• Ada 95 to provide semantics, syntax and formal base.

• MIL-STD-498 (Software development and documentation) to govern structure and documentation for systems work.

An applicatory example is given to show how the “architectural base” can be used to architect and describe complex systems on different levels.

Conclusion and message of this paper is: Ada 95 and MIL-STD-498 can be used, not only for software development, but also to create an architectural base for systems work concerning information systems work in general. This work can be extended to create a formal base for the information aspects of total systems.

Work presented here has been sponsored by the Swedish Defence Material Administration and the Swedish National Board for Industrial and Technical Development. The text is also part of the O4S™ development handbook, part 3.