Frameworks: the future of formal software development?

It could be argued that the primary issue to be dealt with in software engineering today is re-use of software. Current software development rarely, if ever, starts from nothing. Unfortunately, the same cannot be said for the development of specifications. To overcome this problem, various works have attempted to show how specifications can be built using architectural principles. We discuss one such approach in particular, the Architectural Semantics of Open Distributed Processing. We show the limitations of this work with regard to the architecting of specifications and propose a new approach, based on frameworks. To highlight the approach we use the work currently being done in the TOSCA project in its development of a service creation and validation environment for telecommunication services

Specifying Multimedia Binding Objects in Z

The current standardisation activity of Open Distributed Processing (ODP) has attempted to incorporate multimedia flows of information into its architecture through the idea of stream interfaces. At present the reference model of ODP (ODP-RM) abstracts from the precise nature of the flows of information. As a consequence of this, the ODPRM only deals with syntactic aspects of stream interfaces and does not require them to satisfy any behavioural considerations. It is shown in this paper how the formal notation Z can be used to reason about these flows of information in a manner that enables behavioural as well as temporal aspects to be considered. The example given to highlight the approach is the ODP concept of a binding object

Specifying ODP Computational Objects in Z

The computational viewpoint contained within the Reference Model of Open Distributed Processing (RM-ODP) shows how collections of objects can be configured within a distributed system to enable interworking. It prescribes certain capabilities that such objects are expected to possess and structuring rules that apply to how these objects can be configured with one another. This paper highlights how the specification language Z can be used to formalise these capabilities and the associated structuring rules, thereby enabling specifications of ODP systems from the computational viewpoint to be achieved

Specifying ODP Computational Objects in Z

The computational viewpoint contained within the Reference Model of Open Distributed Processing (RM-ODP) shows how collections of objects can be configured within a distributed system to enable interworking. It prescribes certain capabilities that such objects are expected to possess and structuring rules that apply to how these objects can be configured with one another. This paper highlights how the specification language Z can be used to formalise these capabilities and the associated structuring rules, thereby enabling specifications of ODP systems from the computational viewpoint to be achieved

The Invoicing Case Study in (E-)LOTOS

The informal requirements for the invoicing case study are analysed and interpreted. This leads to a high-level specification architecture that can be formalised. Specifications are presented in LOTOS (Language Of Temporal Ordering Specification). For comparison, specifications are also presented E-LOTOS (Enhancements to LOTOS) – the new version of LOTOS currently being standardised. Since LOTOS allows a balance to be struck between process-oriented and data-oriented modelling, specifications in both styles are given. The resulting specifications are evaluated in the context of LOTOS and formal approaches more generally

Validating Architectural Feature Descriptions using LOTOS

The phases of the ANISE project (Architectural Notions In Service Engineering) are briefly explained with reference to the work reported here. An outline strategy is given for translating ANISE descriptions to LOTOS (Language of Temporal Ordering Specification), thus providing a formal basis. It is shown how modular ANISE descriptions of features can be defined and then merged. Potential feature interactions can be identified statically through structural overlaps. A scenario language is introduced to express validation tests for features in a modular fashion, and a number of examples are given. Scenarios are automatically translated to LOTOS and analysed through LOTOS simulation. This allows features to be validated in isolation, and dynamically in combination with other features. The design of the translation and validation tools is discussed, showing typical results when investigating feature descriptions. The paper concludes with a guide to extending the approach for new features

Ensuring specification correctness by construction

We propose a process model for the development of formal and semi-formal specifications based on the notions of multi-view states and development operators. A specification state is composed of a UML and a B view. The development of a specification is seen as a sequence of application of operators, which model design decisions and make both views evolve. To produce consistent specifications, we define a consistency relation between views, allowing to define and check operators' correctness. Thus, the development process guarantees that the specification can be safely verified

Specifying ODP Computational Objects in Z

The computational viewpoint contained within the Reference Model of Open Distributed Processing (RM-ODP) shows how collections of objects can be configured within a distributed system to enable interworking. It prescribes certain capabilities that such objects are expected to possess and structuring rules that apply to how these objects can be configured with one another. This paper highlights how the specification language Z can be used to formalise these capabilities and the associated structuring rules, thereby enabling specifications of ODP systems from the computational viewpoint to be achieved