The process of understanding the system under analysis, the services required of it, its environment and associated constraints involves the capture, analysis and resolution of many ideas, perspectives and relationships at varying levels of detail. We believe requirements methods based on global reasoning lack the expressive framework to adequately articulate this distributed requirements knowledge structure. This paper describes the problems faced in trying to establish an adequate and stable set of requirements and proposes a novel ViewpointOriented Requirements Definition method (VORD) as a means of tackling some of these problems. This method structures the requirements engineering process using viewpoints which are associated with sources of requirements. The paper describes VORD in the light of current viewpoint-oriented requirements approaches and shows how its improves on them. A simple example of a bank auto-teller system is used to demonstrate the method. 3 1.0 Introduction...

this paper is part of a project aiming at advanced support for dynamic modelling in OO software development. We will use the OMT method developed by Rumbaugh et al. as a guideline, but it should be emphasized that the results can be exploited in other methods as well. OMT consists of three modelling techniques: object modelling for describing the static relations and properties of objects, dynamic modelling for describing the behaviour of objects and functional modelling for describing the input--output relations of operations. Of these models, OMT emphasizes the role of the object model---this part is relevant for all applications. Dynamic modelling is needed for specifying the external behaviour of active CCC 0038--0644/94/070643--16 Received 1 November 1993 1994 by John Wiley & Sons, Ltd. Revised 14 March 1994 software such as embedded real-time systems or interactive user interfaces. Since most modern systems have components falling into these categories, dynamic modelling is essential in many cases. Functional modelling is used mainly in computation-oriented applications, such as spreadsheet programs, compilers, CAD systems, etc

This paper describes an empirical investigation into an industrial object-oriented (OO) system comprising 133,000 lines of C++. The system was a sub system of a telecommunications product and was developed using the Shlaer-Mellor method.

The importance of requirements, which in practice often means natural language requirements, for a successful software project cannot be underestimated. Although requirement analysis has been traditionally reserved to the experience of professionals, there is no reason not to use various automatic techniques to the same end. In this paper we present Circe, a Web-based environment for aiding in natural language requirements gathering, elicitation, selection, and validation and the tools it integrates. These tools have been used in several experiments both in academic and in industrial environments. Among other features, Circe can extract abstractions from natural language texts, build various models of the system described by the requirements, check the validity of such models, and produce functional metric reports. The environment can be easily extended to enhance its natural language recognition power, or to add new models and views on them. Keywords: Natural language, requirement engineering, requirement validation, tools, Web-based environments. 1.

. The Unified Modeling Language UML and the Open Modeling Language both have introduced stereotypes as a new means for user-defined extensions of a given base language. Stereotypes are a very powerful feature. They allow modifications ranging from slight notational changes up to the redefinition of the base language. However, the power of stereotypes entails risk. Badly designed stereotypes can do harm to a modeling language. In order to exploit the benefits of stereotypes and to avoid their risks, a better understanding of the nature and the properties of stereotypes is necessary. In this paper, we define a framework that classifies stereotypes according to their expressive power. We identify specific properties and typical applications for stereotypes in each of our four categories and illustrate them with examples. For each category, we discuss strengths and weaknesses of stereotypes and present a preliminary set of stereotype design guidelines. 1 Introduction Since ab...

In object-oriented conceptual modelling, the Generalisation/Specialisation hierarchy and the Whole/Part relationship are prevalent classification schemes for object types. This paper presents an object-oriented conceptual model where, in the end, object types are classified according to two relationships only: existence dependency and generalisation/specialisation. Existence dependency captures some of the interesting semantics that are usually associated with the concept of aggregation (also called composition or Part Of relation), but in contrast with the latter concept, the semantics of existence dependency are very precise and its use clear cut. The key advantage of classifying object types according to existence dependency are the simplicity of the concept, its absolute unambiguity and the fact that it enables to check conceptual schemes for semantic integrity and consistency. We will

Dr. Delbert Tesar, my committee chairman and academic advisor. I would also

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ion: Usually an OO component can be characterized by a noun, e.g., calendar, flight manager, fire alarm system. Operations: Components have operations, and these are characterized in the Operations facet. Operates On: This facet describes the objects that the component acts on, e.g., integers, set, list, resource. Dependencies: These are non-functional dependencies and characteristics which limit the scope of reuse to a certain context, e.g., C++ code, Unix-based software, HOOD design models. An example could be a stack (abstraction) of integer (operates on) written in C++ (dependencies) with operations push, pop, top, and swap. It is possible to have more than one term for each facet. In addition to the terms filled in for the facets, a component will have other attributes, such as size, developer, and date. The distinction between facets and other attributes is that the facets are the properties most relevant for reuse. For the facets, structured term spaces are provided, facilita...

This article describes a technique for analyzing relational specifications. The underlying idea is very simple. Both simulation and checking amount to finding models of a relational formula, i.e., assignments for which the formula is true. For simulation the formula is the description of the operation; for checking, the formula is the negation of an assertion about an operation. Models are found by a generate-and-test strategy: the formula is repeatedly evaluated for a series of assignments until one is found for which the formula is true