Requirements analysis includes a preliminary acquisition step where a global model for the specification of the system and its environment is elaborated. This model, called requirements model, involves concepts that are currently not supported by existing formal specification languages, such as goals to be achieved, agents to be assigned, alternatives to be negotiated, etc. The paper presents an approach to requirements acquisition which is driven by such higher-level concepts. Requirements models are acquired as instances of a conceptual meta-model. The latter can be represented as a graph where each node captures an abstraction such as, e.g., goal, action, agent, entity, or event, and where the edges capture semantic links between such abstractions. Well-formedness properties on nodes and links constrain their instances - that is, elements of requirements models. Requirements acquisition processes then correspond to particular ways of traversing the meta-model graph to acquire approp...

Requirements engineering (RE) is concerned with the identification of the goals to be achieved by the envisioned system, the operationalization of such goals into services and constraints, and the assignment of responsibilities for the resulting requirements to agents such as humans, devices, and software. The processes involved in RE include domain analysis, elicitation, specification, assessment, negotiation, documentation, and evolution. Getting highquality requirements is difficult and critical. Recent surveys have confirmed the growing recognition of RE as an area of utmost importance in software engineering research and practice. The paper presents a brief history of the main concepts and techniques developed to date to support the RE task, with a special focus on modeling as a common denominator to all RE processes. The initial description of a complex safetycritical system is used to illustrate a number of current research trends in RE-specific areas such as go...

In the field of Knowledge Engineering, dissatisfaction with the rapid-prototyping approach has led to a number of more principled methodologies for the construction of knowledgebased systems. Instead of immediately implementing the gathered and interpreted knowledge in a given implementation formalism according to the rapid-prototyping approach, many such methodologies centre around the notion of a conceptual model: an abstract, implementation independent description of the relevant problem solving expertise. A conceptual model should describe the task which is solved by the system and the knowledge which is required by it. Although such conceptual models have often been formulated in an informal way, recent years have seen the advent of formal and operational languages to describe such conceptual models more precisely, and operationally as a means for model evaluation. In this paper, we study a number of such formal and operational languages for specifying conceptual mode...

Research issues related to requirements modeling are introduced and discussed through a review of the requirements modeling language RML, its peers and its successors from the time it was first proposed at the Sixth International Conference on Software Engineering (ICSE-6) to the present---ten ICSEs later. We note that the central theme of "Capturing More World Knowledge" in the original RML proposal is becoming increasingly important in Requirements Engineering. The paper highlights key ideas and research issues that have driven RML and its peers, evaluates them retrospectively in the context of experience and more recent developments, and points out significant remaining problems and directions for requirements modeling research. 1. Introduction "...Requirements definition is a careful assessment of the needs that a system is to fulfill. It must say why a system is needed, based on current and foreseen conditions, which may be internal operations or an external market. It must say wh...

We review basic premises underlying the application of conceptual modelling to the development of information systems and point out a fundamental problem arising from the broad range of concepts that need to be modelled. We then argue that conventional conceptual models are weak for such broad domains of discourse because they come with built-in collections of primitive notions in terms of which conceptual modelling is to be done. Telos is then introduced as a conceptual modelling language designed for capturing knowledge about information systems and it is argued that, unlike its peers, it offers facilities not only for modelling an application but also the notions used to model an application. The presentation of features of the language is eclectic and generally non-technical. Details about Telos can be found in [Mylopoulos90] and [Koubarakis89].

Formal specifications have been a focus of software engineering research for many years and have been applied in a wide variety of settings. Their industrial use is still limited but has been steadily growing. After recalling the essence, role, usage, and pitfalls of formal specification, the paper reviews the main specification paradigms to date and discuss their evaluation criteria. It then provides a brief assessment of the current strengths and weaknesses of today's formal specification technology. This provides a basis for formulating a number of requirements for formal specification to become a core software engineering activity in the future.

In this paper, we propose an object-oriented logical formalism to conceptionally model applications in an interoperable environment. Such an environment consists of heterogeneous and autonomous local (database) systems. Applications in such an environment use several resources and services. Their conceptual modelling involves re-specification of existing systems in terms of homogeneous views, modelling of behavior and system dynamics, modelling of logically distributed components in an open environment and the modeling of communication relationships and dependencies between components. We introduce a formal object-oriented language capable of dealing with these requirements and illustrate its use to model applications in an interoperable environment. 1 Introduction We are currently facing a situation where more and more applications are aiming at integrating and using data and services of local (database) systems [3]. Information has become a key factor in industry, thus it becomes es...

This paper describes our experience in capturing, using a formal specification language, a model of the knowledge-intensive domain of oceanic air traffic control. This model is intended to form part of the requirements specification for a decision support system for air traffic controllers. We give an overview of the methods we used in analysing the scope of the domain, choosing an appropriate formalism, developing a domain model, and validating the model in various ways. Central to the method was the development of a formal requirements engineering environment which provided automated tools for model validation and maintenance

Information systems technology, computer-supported cooperative work practice, and organizational modeling and planning theories have evolved with only accidental contact to each other. Cooperative information systems is a relatively young research area which tries to systematically investigate the synergies between these research fields, driven by the observation that change management is the central issue facing all three areas today and that all three fields have indeed developed rather similar strategies to cope with change. In this paper, we therefore propose a framework which views cooperative information systems as composed from three interrelated facets, viz. the system facet, the group collaboration facet, and the organizational facet. We present an overview of these facets, emphasizing strategies they have developed over the past few years to accommodate change. We also discuss the propagation of change across the facets, and sketch a basic software architecture intended to support the rapid construction and evolution of cooperative information systems on top of existing organizational and technical legacy. 1.

In this paper an extension of high-level Petri nets, namely nested relation/transition nets (NR/T-nets), is described. NR/T-nets allow to model distributed processes and related complex structured objects in business applications. This paper focuses on the development of complex NR/T-net models. Due to their complexity highlevel Petri net models are usually not developed in one single step. Therefore two evolutionary development strategies are introduced: on the one hand incremental construction by iteratively evaluating, refining, formalizing and integrating net fragments, on the other hand adaptation of application-specific reference process and object models. 1 Introduction Processes in business applications are collections of activities associated with a particular business function where the activities are related by the involved objects, persons or resources. Process models should include a specification of the following aspects: . activities and their synchronization, . roles...