Author: Ivan J. Jureta.

Thesis committee: Stephane Faulkner, Pierre-Yves Schobbens, John Mylopoulos, Esteban Zimanyi, Manuel Kolp.

Publication: University of Namur.

Summary. Efficient organization requires rigorous and systematic information management, which encompasses information processing and decision making. Within the efforts in management science and informatics invested towards advancing the knowledge on, and providing assistance to decision making, this thesis focuses on the conceptualizations and techniques intended to facilitate the identification, evaluation, and selection of decisions during the earliest stages of information systems engineering, whereby the systems of interest are deployed to partly or fully automate various organizational processes, including information processing ones. The overall motivating problem that drove to, and that unites the various contributions presented in this thesis is how to better inform decision making and guide it towards decisions that will increase the quality (as evaluated both by the engineer and the stakeholders) of the information system being engineered.

Topics in two key related areas are therefore addressed. First, boundedly rational individuals cannot take engineering decisions by accounting for all information that may be, or actually is available to them. As their information processing abilities are limited and their perception biased, it is necessary to filter the available information to a manageable level, and to bring it to a format that facilitates the rigorous reasoning invested in decision making. Second, it is necessary to provide guidance on how to use the given information in decision making.

The first part of this thesis therefore focuses on conceptualizations that facilitate the identification of relevant information and its organization for subsequent analysis, all in the aim of achieving high quality of the system being engineered. In particular, Part I discusses, shows deficiencies, and accordingly revises the conceptual foundations of requirements engineering, a field of information systems engineering that focuses on the identification and analysis of requirements communicated by the stakeholders to the engineer of the system. The novelty of the suggested revision lies primarily in (i) the separation between functional and nonfunctional (i.e., quality) requirements grounded in a foundational ontology, (ii) the introduction of stakeholders’ communicated attitudes as important sources of information for the evaluation of alternative requirements engineering decisions, (iii) the reformulation of the so-called “requirements problem” - which precisely defines when the requirements engineering effort is successfully completed - to account for attitudes and nonfunctional requirements, and (iv) the recognition of the importance of defeasible reasoning in the search for a solution to the requirements problem. Acknowledging the importance of defeasible reasoning leads - in Part II - to the study of how defeasible reasoning can be incorporated into established decision making processes involved in the identification and analysis of requirements. Novelty in Part II lies mainly in (i) the use of argumentation and justification processes in the modeling and analysis of requirements, (ii) the combined use of design rationale approaches with argumentation and justification, (iii) the recognition that the clarity of arguments is variable (due to ambiguity, vagueness, synonymy, and overgenerality of information going into premises and conclusions in arguments), (iv) the definition of a number of techniques for the detection of unclear information and its clarification, and (v) the use of “clarity” as a criterion for the discrimination among arguments. Part III shows how the conceptualizations and techniques introduced in Parts I and II are applied within and are relevant to the engineering of information systems, including those that rely on heterogeneous and distributed components, as in service-oriented and agent-oriented computing.

Authors: Ivan J. Jureta, Stephane Faulkner, Jean Vanderdonckt.

Publication: Proceedings of the Second IEEE International Conference on Research Challenges in Information Science, RCIS 2008, Marrakech, Morocco.

Abstract. A pluripotent information system is an open and distributed information system that (i) automatically adapts at runtime to changing operating conditions, and (ii) satisfies both the requirements anticipated at development time, and those unanticipated before but relevant at runtime. Engineering pluripotency into an information system therefore responds to two recurring critical issues: (i) the need for adaptability given the uncertainty in a system’s operating environment, and (ii) the difficulty to fully anticipate and account for all possible stakeholders’ requirements at development time and respond to the change of requirements at runtime. We draw on our group’s research efforts over the last two years to show and discuss how pluripotency can be engineered into information systems.

Authors: Ivan J. Jureta, Stephane Faulkner.

Publication: Proceedings of the Second IEEE International Conference on Research Challenges in Information Science, RCIS 2008, Marrakech, Morocco.

Abstract. Requirements engineers analyze information system (IS) requirements with a number of explicit and implicit assumptions about human organizations. Such assumptions influence the construction and use of requirements engineering (RE) frameworks. Ultimately, they affect IS requirements’ quality. This paper overviews recent goal-oriented RE (GORE) frameworks by discussing three assumptions about human organizations: bounded human rationality, opportunism in human behavior, and organizational complexity. A discussion of implications results in a set of desirable and undesirable characteristics for GORE frameworks. They are implemented in a framework, named REQUEST, to illustrate one possible implementation in a RE framework. Theoretical discussions are interwoven with examples from a real world industrial case study in which REQUEST was used to engineer IS requirements at a large international steel producer.

Authors: Ivan J. Jureta, Stephane Faulkner, Pierre-Yves Schobbens.

Publication: Accepted for publication in the Requirements Engineering Journal.

Abstract. Representation and reasoning about goals of an information system unavoidably involve the transformation of unclear stakeholder requirements into an instance of a goal model. If the requirements engineer does not justify why one clear form of requirements is chosen over others, the subsequent modeling decisions cannot be justified either. If arguments for clarification and modeling decisions are instead explicit, justifiably appropriate instances of goal models can be constructed and additional analyses applied to discover richer sets of requirements. The paper proposes the “Goal Argumentation Method (GAM)” to fulfil three roles: (i) GAM guides argumentation and justification of modeling choices during the construction or critique of goal model instances; (ii) it enables the detection of deficient argumentation within goal model instances; and (iii) it provides practical techniques for the engineer to ensure that requirements appearing both in arguments and in model instance elements are clear.

Authors: Ivan J. Jureta, Stephane Faulkner, Philippe Thiran.

Publication: 15th IEEE International Conference on Requirements Engineering (RE 2007), New Delhi, India.

Abstract: The Dynamic Requirements Adaptation Method (DRAM) is suggested to assist existing RE methodologies in updating requirements specifications at runtime for adaptable and open service-oriented systems. Updates are needed because an adaptable and open system continually changes how and to what extent initial requirements are achieved.

Authors: Ivan J. Jureta, Stephane Faulkner.

Publication: Proceedings of Conceptual Modeling - ER 2007, 26th International Conference on Conceptual Modeling, Auckland, New Zealand.

Abstract. Representation and reasoning about information system (IS) requirements is facilitated with the use of goal models to describe the desired and undesired IS behaviors. One difficulty in goal modeling is arriving at a shared understanding of a goal model instance, mainly due to different backgrounds of the system stakeholders who participate in modeling, and the subsequent disparate use of terminology. Lack of shared understanding, or, in other words, the presence of multiple interpretations entails no guarantee that stakeholders’ expectations expressed in the model instance will be appropriately understood during the subsequent steps of system development. Among the many potential causes of multiple interpretations, this paper focuses on a critical set of such causes, namely: ambiguity, overgenerality, synonymy, and vagueness of information represented in instances of goal modeling primitives. The “Goal Clarification Method” is suggested to guide the identification of unclear information and the subsequent clarification thereof.

Authors: Ivan J. Jureta, Stephane Faulkner, Youssef Achbany, Marco Saerens.

Publication: Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems (AAMAS 2007), Honolulu, Hawai’i.

Abstract. A MAS architecture consisting of service centers is proposed. Within each service center, a mediator coordinates service delivery by allocating individual tasks to corresponding task specialist agents depending on their prior perfomance while anticipating performance of newly entering agents. By basing mediator behavior on a novel multicriteria-driven (including quality of service, deadline, reputation, cost, and user preferences) reinforcement learning algorithm, integrating the exploitation of acquired knowledge with optimal, undirected, continual exploration, adaptability to changes in agent availability and performance is ensured. The reported experiments indicate the algorithm behaves as expected and outperforms two standard approaches.

Authors: Ivan J. Jureta, Stephane Faulkner.

Publication: Proceedings of Conceptual Modeling - ER 2007, 26th International Conference on Conceptual Modeling, Auckland, New Zealand.

Abstract. Neglecting traceability - i.e., the ability to describe and follow the life of a requirement - is known to entail misunderstanding and miscommunication, leading to the engineering of poor quality systems.  Following the simple principles that (a) changes to UML model instances ought be justified to the stakeholders, (b) justification should proceed in a structured manner to ensure rigor in discussions, critique, and revisions of model instances, and (c) the concept of argument instantiated  in a justification process ought to be well defined and understood, the present paper introduces the UML Traceability through Argumentation Method (UML-TAM) to enable the traceability of design rationale in UML while allowing the appropriateness of model changes to be checked by analysis of the structure of the arguments provided to justify such changes.

Note: This is the RIGIM@ER07 keynote presented by John Mylopoulos.

Authors: John Mylopoulos, Ivan J. Jureta, Stephane Faulkner.

Publication: Proceedings of the First International Workshop on Requirements, Intentions and Goals in Conceptual Modeling (RIGiM) Conceptual Modeling - ER 2007, 26th International Conference on Conceptual Modeling, Auckland, New Zealand.

Abstract. In the good old days, the world of Requirements Engineering (RE) was simple: there were functional requirements to be modelled, somehow, and non-functional ones that usually consisted of a product quality wish list. Solving a particular requirements problem amounted to (loosely-understood) accommodation of functional requirements and doing one’s best with non-functional ones. This world changed dramatically with the advent of Goal-Oriented Requirements Engineering. The primitive concepts in terms of which requirements are now conceived are no longer functions, states and things. Instead, the brave new world is populated with goals, stakeholder intentions and social settings. We review, contrast and compare some of the new and old concepts, including goal, intention, function, preference, priority, softgoal, quality, criterion, and non-functional requirement. In addition, we attempt to organize them into a new ontology for requirements. We also present first results on a theory of requirements where, given a requirements problem, we define precisely what is a solution and what is an optimal solution.

Authors: Ivan J. Jureta, Stephane Faulkner, Pierre-Yves Schobbens.

Publication: Proceedings of the First International Workshop on Requirements, Intentions and Goals in Conceptual Modeling (RIGiM) Conceptual Modeling - ER 2007, 26th International Conference on Conceptual Modeling, Auckland, New Zealand.

Abstract. Definitions of the concepts derived from the goal concept (including functional and nonfunctional goal, hardgoal, and softgoal) used in requirements engineering are discussed, and precise (and, when appropriate, mathematical) definitions are suggested. The concept of satisficing, associated to softgoals is revisited. A softgoal is satisficed when thresholds of some precise criteria are reached. Satisficing does not cover situations in which continual improvement of thresholds is expected. The notion of excelling is suggested to cover such cases, along with the concept of disposition to represent and reason about excelling.