LCM and MCM: specification of a control system using dynamic logic and process algebra

LCM 3.0 is a specification language based on dynamic logic and process algebra, and can be used to specify systems of dynamic objects that communicate synchronously. LCM 3.0 was developed for the specification of object-oriented information systems, but contains sufficient facilities for the specification of control to apply it to the specification of control-intensive systems as well. In this paper, the results of such an application are reported. The paper concludes with a discussion of the need for theorem-proving support and of the extensions that would be needed to be able to specify real-time properties

An Object Oriented Paradigm for Requirements Specifications.

Software engineering defines a formalized five-step life-cycle for software development. These steps are: requirements specification, design, implementation, testing and maintenance. The requirements specification phase of the software development life-cycle is responsible for determining the functionality of the proposed system. In this work, a methodology is developed that enhances the generation of accurate requirements specifications, utilizing an object-oriented paradigm. This research realizes four objectives. First, the process of information transferral between the user and the specification team is enhanced. Second, a working base of knowledge containing the domain-specific information within the initial requirements document is established for use by the specification team. Third, techniques for evaluating the overall quality of the initial requirements document are addressed. Specifically, the problems associated with document ambiguity, completeness, consistency and structure are examined. Finally, a specification paradigm is defined utilizing this knowledge-based specification environment. The paradigm permits the automatic generation of an object-oriented specification model. This model may then be used as an input for the design phase. This paradigm defines a methodology for the establishment and evaluation of the knowledge-based specification environment. The environment permits the incorporation of an object-oriented development strategy into the specification process. In addition, the concept of information traceability throughout the specification process is enhanced

Integrating BON and Object-Z.

A significant limitation with object-oriented formal specification languages, such as Object-Z, is that they lack development and management processes, which can be used to guide the production of reliable, robust object-oriented systems. An integration of an object-oriented methodology, BON, and Object-Z is presented in order to add an industrially validated development process to Object-Z. An extensible CASE tool for BON is also described that supports the integration with an Object-Z code generation engine

Rigorous object-oriented analysis

Object-oriented methods for analysis, design and programming are commonly used by software engineers. Formal description techniques, however, are mainly used in a research environment. We have investigated how rigour can be introduced into the analysis phase of the software development process by combining object-oriented analysis (OOA) methods with formal description techniques. The main topics of this investigation are a formal interpretation of the OOA constructs using LOTOS, a mathematical definition of the basic OOA concepts using a simple denotational semantics and a new method for object- oriented analysis that we call the Rigorous Object-Oriented Analysis method (ROOA). The LOTOS interpretation of the OOA concepts is an intrinsic part of the ROOA method. It was designed in such a way that software engineers with no experience in LOTOS, can still use ROOA. The denotational semantics of the concepts of object-oriented analysis illuminates the formal syntactic transformations within ROOA and guarantees that the basic object- oriented concepts can be understood independently of the specification language we use. The ROOA method starts from a set of informal requirements and an object model and produces a formal object-oriented analysis model that acts as a requirements specification. The resulting formal model integrates the static, dynamic and functional properties of a system in contrast to existing OOA methods which are informal and produce three separate models that are difficult to integrate and keep consistent. ROOA provides a systematic development process, by proposing a set of rules to be followed during the analysis phase. During the application of these rules, auxiliary structures are created to help in tracing the requirements through to the final formal model. As LOTOS produces executable specifications, prototyping can be used to check the conformance of the specification against the original requirements and to detect inconsistencies, omissions and ambiguities early in the development process

Modeling the dialogue aspects of an information system.

In this paper we investigate techniques offered by current object-oriented development methods for the specification of the user-system dialogue aspect of a software system. Current development methods do not give very extensive guidelines on how to model this aspect and the available techniques need some refinement and elaboration to fit this particular task in the software specification process. The paper first compares a number of approaches. The common elements of these approaches are summarized and further developed into one comprehensive set of techniques that addresses the needs of functional requirements analysis.

Engineering Object-Oriented Semantics Using Graph Transformations

In this paper we describe the application of the theory of graph transformations to the practise of language design. We have defined the semantics of a small but realistic object-oriented language (called TAAL) by mapping the language constructs to graphs and their operational semantics to graph transformation rules. In the process we establish a mapping between UML models and graphs. TAAL was developed for the purpose of this paper, as an extensive case study in engineering object-oriented language semantics using graph transformation. It incorporates the basic aspects of many commonly used object-oriented programming languages: apart from essential imperative programming constructs, it includes inheritance, object creation and method overriding. The language specification is based on a number of meta-models written in UML. Both the static and dynamic semantics are defined using graph rewriting rules. In the course of the case study, we have built an Eclipse plug-in that automatically transforms arbitrary TAAL programs into graphs, in a graph format readable by another tool. This second tool is called Groove, and it is able to execute graph transformations. By combining both tools we are able to visually simulate the execution of any TAAL program

Modelchecking non-functional requirements for interface specifications.

In this paper we present a combination of formal specification and mechanical analysis enabling a simple and flexible development process for interface specifications from requirements. Using the potential of temporal logic for describing non-functional requirements we derive an analysis model from functional requirements. Slightly abusing its original object-oriented incentives we employ the precision and modularity of formal specification in Object-Z for representing interface descriptions. A structure preserving translation of Object-Z specifications to the model checker SMV unifies the temporal logic specification of requirements with the analysis model. The automated verification in SMV supports a feedback loop for a stepwise improvement of the requirement specification and its analysis model. We illustrate this technique on the case study of the safety-critical TWIN elevator system