Even though goal modelling is an effective approach to requirements engineering, it is known to present a number of difficulties in practice. The paper discusses these difficulties and proposes to couple goal modelling and scenario authoring to overcome them. Whereas existing techniques use scenarios to concretise goals, we use them to discover goals. Our proposal is to define enactable rules which form the basis of a software environment called L'Ecritoire to guide the requirements elicitation process through interleaved goal modelling and scenario authoring. The focus of the paper is on the discovery of goals from scenarios. The discovery process is centred around the notion of a Requirement Chunk (RC) which is a pair <Goal, Scenario>. The paper presents the notion of RC, the rules to support the discovery of RCs and illustrates the application of the approach within L'Ecritoire using the ATM example. It also evaluates the potential practical benefits expected from the use of the app...

Abstract—Scenarios are increasingly recognized as an effective means for eliciting, validating, and documenting software requirements. This paper concentrates on the use of scenarios for requirements elicitation and explores the process of inferring formal specifications of goals and requirements from scenario descriptions. Scenarios are considered here as typical examples of system usage; they are provided in terms of sequences of interaction steps between the intended software and its environment. Such scenarios are in general partial, procedural, and leave required properties about the intended system implicit. In the end such properties need to be stated in explicit, declarative terms for consistency/completeness analysis to be carried out. A formal method is proposed for supporting the process of inferring specifications of system goals and requirements inductively from interaction scenarios provided by stakeholders. The method is based on a learning algorithm that takes scenarios as examples/counterexamples and generates a set of goal specifications in temporal logic that covers all positive scenarios while excluding all negative ones. The output language in which goals and requirements are specified is the KAOS goal-based specification language. The paper also discusses how the scenario-based inference of goal specifications is integrated in the KAOS methodology for goal-based requirements engineering. In particular, the benefits of inferring declarative specifications of goals from operational scenarios are demonstrated by examples of formal analysis at the goal level, including conflict analysis, obstacle analysis, the inference of higherlevel goals, and the derivation of alternative scenarios that better achieve the underlying goals. Index Terms—Scenario-based requirements elicitation, inductive inference of specifications, goal-oriented requirements engineering, specification refinement and analysis, lightweight formal methods. 1

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An approach for guiding the construction of use case specifications is presented. A use case specification comprises contextual information of the use case, its change history, the complete graph of possible pathways, attached requirements and open issues. The proposed approach delivers a use case specification as an unambiguous natural language text. This is done by a stepwise and guided process which progressively transforms initial and partial natural language descriptions of scenarios into well structured, integrated use case specifications. The basis of the approach is a set of linguistic patterns and linguistic structures. The former constitutes the deep structure of the use case specification whereas the latter corresponds to the surface structures. The paper presents the use case model, the linguistic basis and the guided process along with the associated guidelines and support rules. The process is illustrated with the automated teller machine (ATM) case study.

A method for scenario-based requirements engineering is described. The method uses two types of scenario: structure models of " the system context and scripts of system usage. A modelling language is reported for describing scenarios, and heuristics are given to crosscheck dependencies between scenario models and the requirements specification. Heuristics are grouped into several anah,tic treatments that investigate correspondences between users' goals and system fimctions; input events and system processes to deal with them: system output and its destination in the scenario model, and acceptability anah,sis of system output for different stakehoMetw. The method is i/htstrated with a case study taken from the London Ambulance Service report. The prospects for scenario-based requirements engineering and related work are discussed.

Kaserntryckeriet, Karlskrona 2002 &quot;Real knowledge is to know the extent of one's ignorance.“

: Scenario-based approaches are becoming ubiquitous in systems analysis and design but their definition and scope remain vague. Complementing the recently proposed CREWS classification framework for scenario-based RE, this paper reports on an exploratory survey of practice conducted through site visits with 15 projects in four European countries. The main findings include that: (1) the variety of purposes and uses of scenarios in the process is much greater than expected; (2) as a consequence, we must take scenarios much more seriously as important design artifacts, offering better means for structuring, management, and evolution. To handle these complex processes, users request more explicit methodological guidance and more adequate tool support. 1. Introduction Scenario-based approaches are attracting more and more interest in requirements engineering research and practice. The research literature offers an increasing number of scenario-related methods, models and notations. The con...

The elicitation, modeling and analysis of requirements have consistently been one of the main challenges during the development of complex systems. Telecommunication systems belong to this category of systems due to the worldwide distribution and the heterogeneity of today’s telecommunication networks. Scenarios and use cases have become popular for capturing and analyzing requirements. However, little research has been done that compares different approaches and assesses their suitability for the telecommunications domain. This paper defines evaluation criteria and then reviews fifteen scenario notations. In addition, twenty-six approaches for the construction of design models from scenarios are briefly compared.

. The paper proposes a faceted framework to understand and classify issues in system development process engineering. The framework identifies four different but complementary view-points. Each view allows us to capture a particular aspect of process engineering. Inter-relationships between these aspects allow us to show the influence that one aspect has on another. In order to study, understand and classify a particular aspect of process engineering in its diversity we associate a set of facets with each aspect. The paper uses the framework to raise questions, problems and research issues in the field. 1. INTRODUCTION Process engineering is considered today as a key issue by both the software engineering and information systems engineering communities. Recent interest in process engineering is part of the shift of focus from the product to the process view of systems development. Process engineering is a rather new research area. Consequently there is no consensus on, for example, wh...

The elicitation, modeling and analysis of requirements have consistently been one of the main challenges during the development of complex systems. Telecommunication systems belong to this category of systems due to the worldwide distribution and the heterogeneity of today’s telecommunication networks. Many proposals have been made for approaches that allow the developer to describe system behavior. Scenarios and use cases represent one such approach that has become popular for the capturing and analysis of requirements. However, little research has been done that compares different approaches and assesses their suitability for the telecommunications domain. This paper defines evaluation criteria for scenario notations and then uses these criteria to review twelve scenario notations. In addition, nineteen approaches for the construction of more detailed and integrated design models from scenarios are briefly compared. Such models enable further analysis and pave the way towards automated generation of implementations. Hopes and challenges related to scenario-based development of telecommunication systems are finally discussed.