Mirko Morandini

Towards goal-oriented development of self-adaptive systems

Self-adaptive software aims at anticipating changes which occur in a complex environment and to automatically deal with them at run-time. The increasing demand for complex networked software, which makes computing resources available to anyone, anywhere and at any time, is drawing attention to the engineering of self-adaptive software. The objective of our work is to define a process and a tool-supported design framework to develop self-adaptive systems, which consider Belief-Desire-Intention agent models as reference architectures. We adopt an agent-oriented approach, which allows to explicitly model system goals in requirements specification and in the system architecture design. Moreover, goal achievement conditions are specified along with their relationships with the environment and with possible failures, and corresponding recovery actions. This paper aims at motivating and giving an overview of our approach with the help of an example.

Tool-supported development with Tropos: the conference management system case study

The agent-oriented software engineering methodology Troposoffers a structured development process and supporting tools fordeveloping complex, distributed systems. The objective of this paper is twofold: first, to illustrate the use ofTropos to develop a Multi-Agent System, performing basic analysis anddesign activities, code generation and testing, with the support of a setof tools; second, to enable the comparison with other, tool-supported,agent-oriented software engineering methodologies through a descriptionof the main steps of these activities and of excerpts of the resultingartefacts, with reference to a common case study, namely, the ConferenceManagement System case study.

A Goal-Oriented Approach for Modelling Self-organising MAS

Autonomous software agents provide a promising solution to the needs of decentralised networked systems, able to adapt their behaviour in a complex and dynamically changing environment. Current agent-oriented software engineering methodologies tend to focus on different levels to realise such a self-adapting behaviour, namely the agent individual level and the global system level. The first requires to design a goal-directed agent behaviour, the second to design agents able to optimize their coordination with other peer agents in the organization, giving rise to system-level adaptation. In this paper we propose to extend a goal-oriented engineering methodology to deal with the modelling of organisations that are able to self-organise in order to reach their goals in a changing environment. To deliver on this aim, we combine Tropos4AS , an extension of TROPOS for adaptive systems, with concepts, guidelines and modelling steps from the ADELFE methodology, which provides a bottom-up approach for engineering collaborative multi-agent societies with an emergent behaviour. The resulting MAS has self-adaptation properties, having agents that are able to change their behaviour according to changes in the environment, and having organisations that adapt themselves to changing needs. The approach is illustrated by modelling a collaborative multi-agent system for conference management.

Modelling Self-Adaptivity: A Goal-Oriented Approach

Self-adaptive systems aim at autonomously achieving their objectives in a dynamic environment, adapting their behavior to different circumstances. We claim that appropriate software engineering methodologies are needed to define and to model the information necessary for a system to perform autonomous diagnosis and decision making at runtime.In this short paper we focus on conceptual modeling for the design of self-adaptive software. Our design framework adopts a goal-oriented approach to specify variability in system requirements, coping with some limits of current goal modeling approaches.

Engineering requirements for adaptive systems

Abstract The increasing demand for complex and distributed software calls for novel software engineering methods and techniques, to create systems able to autonomously adapt to dynamically changing situations. In this paper, we present a framework for engineering requirements for adaptive software systems. The approach, called Tropos4AS, combines goal-oriented concepts and high-variability design methods. The Tropos4AS requirements model can be directly mapped to software prototypes with an agent-oriented architecture which can be executed for requirements validation and refinement. We give a comprehensive description of the framework, with conceptual models, modelling guidelines, and supporting tools. The applicability of the framework to requirements validation and refinement is illustrated through a case study. Two controlled experiments with subjects provide an empirical evaluation of the proposed modelling language, with statistical evidence of the effectiveness of the modelling approach for gathering requirements of adaptive systems.

Automated Mapping from Goal Models to Self-Adaptive Systems

Self-adaptive systems should autonomously adapt at run time to changes in their operational environment, guided by the goals assigned by their stakeholders. We present a tool that supports goal-oriented modelling and generation of code for goal-directed, self-adaptive systems, supporting Tropos4AS, an extension of the software engineering methodology Tropos.

A design framework for generating BDI-agents from goal models

We define a tool-supported design framework that allows to specify an agent goal model and to automatically generate fragments of a BDI agent from it. We devise the design process as a transformation process from platform-independent design models to platform-specific models and then to code. The design framework is demonstrated by referring to the Tropos methodology and to the JADE/Jadex platform. In this short paper, key steps in the process are illustrated through an example.

Modelling Risks in Open Source Software Component Selection

Adopting Open Source Software (OSS) components is a decision that offers many potential advantages – such as cost effectiveness and reputation – but even introduces a potentially high number of risks, which span from the inability of the OSS community to continue the development over time, to a poor quality of code. Differently from commercial off-the-shelf components, to assess risk in OSS component adoption, we can rely on the public availability of measurable information about the component code and the developing communities. In the present paper, we present a risk evaluation technique that uses conceptual modelling to assess OSS component adoption risks. We root it in the existing literature on OSS risk assessment and validate it by means of our industrial partners.

Who is the expert? combining intention and knowledge of online discussants in collaborative RE tasks

Large, distributed software development projects rely on the collaboration of culturally heterogeneous and geographically distributed stakeholders. Software requirements, as well as solution ideas are elicited in distributed processes, which increasingly use online forums and mailing lists, in which stakeholders mainly use free or semi-structured natural language text. The identification of contributors of key information about a given topic --called experts, in both the software domain and code-- and in particular an automated support for retrieving information from available online resources, are becoming of crucial importance. In this paper, we address the problem of expert finding in mailing-list discussions, and propose an approach which combines content- and intent-based information extraction for ranking online discussants with respect to their expertise in the discussed topics. We illustrate its application on an example.

Risk Awareness in Open Source Component Selection

Adopting Open Source Software (OSS) components offers many potential advantages – such as cost effectiveness and increased reputation – but also introduces a variety of new risks related to the intrinsic fluidity of the OSS development projects. In this paper, we present results of a systematic literature review on OSS adoption risks, which allows to relate them to available OSS measures. Relying on the results of the review, we also present a risk-aware selection process, which uses OSS measures to rank OSS project according to the adopter’s criteria, improving the quality of the OSS component selection.