Carlos Cares

Towards interoperability of i* models using iStarML

Goal-oriented and agent-oriented modelling provides an effective approach to the understanding of distributed information systems that need to operate in open, heterogeneous and evolving environments. Frameworks, firstly introduced more than ten years ago, have been extended along language variants, analysis methods and CASE tools, posing language semantics and tool interoperability issues. Among them, the i* framework is one the most widespread. We focus on i*-based modelling languages and tools and on the problem of supporting model exchange between them. In this paper, we introduce the i* interoperability problem and derive an XML interchange format, called iStarML, as a practical solution to this problem. We first discuss the main requirements for its definition, then we characterise the core concepts of i* and we detail the tags and options of the interchange format. We complete the presentation of iStarML showing some possible applications. Finally, a survey on the i* community perception about iStarML is included for assessment purposes.

SYSTEMATIC CONSTRUCTION OF i STRATEGIC DEPENDENCY MODELS FOR SOCIO-TECHNICAL SYSTEMS

Goal- and agent-oriented models have become a consolidated type of artifact in various software and knowledge engineering activities. Several languages exist for representing such type of models but there is a lack of associated methodologies for guiding their construction up to the necessary level of detail. In this paper we present RiSD, a method for building Strategic Dependency (SD) models in the i* notation. RiSD is defined in a prescriptive way to reduce uncertainness when constructing the model. RiSD tackles three fundamental issues: (1) it tends to reduce the average size of the resulting models; (2) it defines some traceability relationships among model elements; (3) it provides some lexical and syntactical conventions. As a result, we may say that RiSD supports the construction process of goal- and agent-oriented models whilst increasing their understanding.

A metamodelling approach for i* model translations

The i* (i-star) framework has been widely adopted by the information systems community. Since the time it was proposed, different variations have arisen. Some of them just propose slight changes in the language definition, whilst others introduce constructs for particular usages. This flexibility is one of the reasons that makes i* attractive, but it has as counterpart the impossibility of automatically porting i This lack of interoperability makes difficult to build a repository of models, to adopt directly techniques defined for one variation, or to use i* tools in a feature-oriented instead of a variant-oriented way. In this paper, we explore in more detail the interoperability problem from a metamodel perspective. We analyse the state of the art concerning variations of the i* language, from these variations and following a proposal from Wachsmuth, we define a supermetamodel hosting identified variations, general enough so as to embrace others yet to exist. We present a translation algorithm oriented to semantic preservation and we use the XML-based iStarML interchange format to illustrate the interconnection of two tools.

On the joint use of i ∗ with other modelling frameworks: A vision paper

The use of the i∗ (iStar) framework by the requirements engineering community is many-fold. Among the several possible engineering cases, we are particularly interested here in the joint use of i∗ with other modelling frameworks to obtain what we call i∗-based frameworks. In this context, several challenges need to be overcome: theoretical, technical, methodological and community-related. In this paper, we review current i∗-based frameworks under several possible scenarios and observe that not all of these challenges are always addressed, and even more, there is lack of guidelines or well-accepted methodological design steps on how to overcome these issues. Then, we detail the several engineering artifacts and techniques whose consideration in i∗-based frameworks may help to overcome them. To illustrate the vision, we present the case of combining i∗ with data warehouse models, from the initial definition of the ontology to the final implementation using profiles. Finally, we provide a research agenda to apply the proposed vision including a final reflection on defining a maturity model as a convenient way to support forthcoming research in the topic.

Goal-Driven Agent-Oriented Software Processes

The quality of software processes is acknowledged as a critical factor for delivering quality software systems. Any initiative for improving the quality of software processes requires their explicit representation and management. A current representational metaphor for systems is agent orientation, which has become one of the recently recognized engineering paradigms. In this article, we argue for the convenience of representing the software process using an agent-oriented language to model it and a goal-driven procedure to design it. Particularly we propose using the i* framework which is both an agent- and a goal-oriented modeling language. We review the possibilities of i* as a software process modeling language, and we also show how success factors can be made explicit in i* representations of the software processes. Finally, we illustrate the approach with an example based on the development of a set of ergonomic and safety software tools

Extending tropos for a prolog implementation: a case study using the food collecting agent problem

There is a recognized lack of Agent-Oriented Methodologies to translate a design into a computational logic implementation. In this paper we address this problem by extending Tropos, which is one of the most used methodologies to design agent systems. We show our proposal with the Food Collecting Agent Problem in which a team has to collect food in a grid-like world. Our solution includes autonomous behaviour, beliefs, multiple roles playing, communication and cooperation. The main contribution is the proposal to generate a Prolog implementation from a Tropos design by first extending the Tropos de-tailed design and second illustrating how to get a set of Prolog clauses for this design. In addition we show a performance evaluation of our Prolog implementation which confirms that our solution for the case study is effective and allows a simple configuration of the resulting program.

The i* framework for goal-oriented modeling

i* is a widespread framework in the software engineering field that supports goal-oriented modeling of socio-technical systems and organizations. At its heart lies a language offering concepts such as actor, dependency, goal and decomposition. i* models resemble a network of interconnected, autonomous, collaborative and dependable strategic actors. Around this language, several analysis techniques have emerged, e.g., goal satisfaction analysis and metrics computation. In this work, we present a consolidated version of the i* language based on the most adopted versions of the language. We define the main constructs of the language and we articulate them in the form of a metamodel. Then, we implement this version and a concrete technique, goal satisfaction analysis based on goal propagation, using ADOxx. Throughout the chapter, we used an example based on open source software adoption to illustrate the concepts and test the implementation.

An Overview of Syntactic and Semantic Issues in Software Product Lines

Feature models are at the core of Software Product Lines (SPL). Along the years different feature modeling languages have been proposed. Although they share a set of core concepts, feature languages present differences such as specification meta language, visual and textual emphasis and language constructs, among others. The result of this situation is a contemporary set of dialects with dissimilarities. This paper presents a metamodel and a semantic framework to categorize syntactic variations and semantic anomalies in SPL.

Selecting mobile office devices using a goal-oriented approach

The mobile office devices market is currently growing, mainly due to the descending cost of wireless technology as well as the high diversity of functions and features covered. Diversity and proliferation become a hard problem when a person or organization aims at selecting the appropriate device for their particular needs. We propose here a framework for producing device recommendations based on personal or business needs. The framework is articulated through an architecture that includes subsystems for data extraction, recommendation and personalization. All these subsystems operate upon a goaloriented knowledge base whose presentation is the subject of this paper. Our approach is built upon three independent models: a market model, which contains descriptions of the current devices offered in the marketplace; a domain model, which states the needs of the person or organization; a mediator model, which describes the types of devices available. We show the actors and processes around these models. Last, we present a prototype that acts as proof-of-concept of the recommender system.

On Optimizing the Path to Information Security Compliance

Information Security Management has been contemporarily confronted by standards covering business aspects related to Information Technology. Different standards map the problem of information security to a set of controls that represent safeguards for different security vulnerabilities. Several procedure-oriented maturity models have been proposed for managing the progress on information security, however, few approaches use quantitative techniques for analyzing the progress on information security. In this paper we propose that the problem of becoming security compliance can be analyzed as a problem of multi-paths where checking different controls means choosing different ways of reaching a security compliance. We identify a set of concepts from security ontologies in order to identify a set of variables influencing these paths. The main contribution is formulating the problem of reaching some standard compliance in the shape of optimization problems, thus existing optimization techniques can be applicable.