Automated Analysis of Compositional Multi-Agent Systems

Abstract. An approach for handling the complex dynamics of a multi-agent system is based on distinguishing aggregation levels. The behaviour at a given aggregation level is specified by a set of dynamic properties at that level, expressed in some (temporal) language. Such behavioural specifications may be complex and difficult to analyse. To enable automated analysis of system specifications, a simpler format is required. To this end, a specification at a lower aggregation level can be created, describing basic steps in the processes of a system. This paper presents a method and tool to support the automated creation of such a specification, as a refinement of a given higher level specification. The generated specification has a simple format which can easily be used for analysis. This paper describes an approach for automated verification of logical consequences of specifications using model checking techniques

Constraint-based Modelling of Organisations

Modern organisations are characterised by a great variety of forms and often involve many actors with diverse goals, performing a wide range of tasks in changing environmental conditions. Due to high complexity, mistakes and inconsistencies are not rare in organisations. To provide better insights into the organisational operation and to identify different types of organisational problems explicit specification of relations and rules, on which the structure and behaviour of an organisation are based, is required. Before it is used, the specification of an organisation should be checked for internal consistency and validity w.r.t. the domain. To this end, the paper introduces a framework for formal specification of constraints that ensure the correctness of organisational specifications. To verify the satisfaction of constraints, efficient and scalable algorithms have been developed and implemented. The application of the proposed approach is illustrated by a case study from the air traffic domain

Formal Modelling of Goals in Organizations

Each organization exists or is created for the achievement of one or more goals. To ensure continued success, the organization should monitor its performance with respect to the formulated goals. In practice the performance of an organization is often evaluated by estimating its performance indicators. In most existing approaches on organization modelling the relation between performance indicators and goals remains implicit. This paper proposes a formal framework for modelling goals based on performance indicators and defines mechanisms for establishing goal satisfaction, which enable evaluation of organizational performance. Methodological and analysis issues related to goals are discussed in the paper. The described framework is a part of a general framework for organization modelling and analysis

Formal and computational modeling of anticipation mechanisms of resilience in the complex sociotechnical air transport system

With ever-growing numbers of passengers and complexity of the air transport system, it becomes more and more of a challenge to manage the system in an effective, safe, and resilient manner. This is especially evident when disruptions occur. Understanding and improving resilience of the air transport system and its adaptive capacity to disruptions is essential for the system’s uninterrupted successful performance. Using theoretical findings from behavioral sciences, this paper makes the first steps towards formalization of the adaptive capacity of resilience of the air transport system with a particular focus on its ability to anticipate. To this end, an expressive logic-based language called Temporal Trace Language is used. The proposed approach is illustrated by a case study, in which anticipatory mechanisms are implemented in an agent-based airport terminal operations model, to deal with a disruptive scenario of unplanned and challenging passenger demand at the security checkpoint. Results showed that the timing of an adaptive action could have a significant influence on reducing the risk of saturation of the system, where saturation implies performance loss. Additionally, trade-off relations were obtained between cost, corresponding to the extra resources mobilized, and the benefits, such as a decrease in risk of saturation of the passenger queue. Document type: Articl

Airline Network Planning Considering Climate Impact: Assessing New Operational Improvements

The aviation industry has set an ambitious goal of reducing its climate impacts. Accordingly, airlines must balance their plans according to this goal with financial considerations. We developed a multi-objective framework to facilitate climate-aware network design by incorporating the objective to minimise the flight average temperature response (ATR) when optimising the airline network. We also assessed the operational improvements (OIs) which are introduced to improve sustainability in airline operations. In particular, we considered intermediate stop-overs (ISOs) and lower flight altitudes as OIs in our case studies. We analysed the impact of considering the climate impact in the planning of operations of three different airline types: one main-hub-and-spoke (KLM), one smaller multi-hub airline (TAP), and one low-cost carrier (EasyJet). The results show that airlines could also lower their environmental impact by 10–36% when considering the ATR as an objective. However, this would require an 8–20% reduction in profits. Adopting lower-altitude flying with ISO could mitigate their climate impact by 27–49% while reducing profits by approximately 6%. Our study highlights the importance of considering the airline network as a whole and demonstrates the potential benefits of operational improvements from a network perspective

A Framework for Formal Modeling and Analysis of Organizations

A new, formal, role-based, framework for modeling and analyzing both real world and artificial organizations is introduced. It exploits static and dynamic properties of the organizational model and includes the (frequently ignored) environment. The transition is described from a generic framework of an organization to its deployed model and to the actual agent allocation. For verification and validation of the proposed model, a set of dedicated techniques is introduced. Moreover, where most computational models can handle only two or three layered organizational structures, our framework can handle any arbitrary number of organizational layers. Henceforth, real-world organizations can be modeled and analyzed, as illustrated by a case study, within the DEAL project line. © Springer Science+Business Media, LLC 2007

An ambient agent architecture exploiting automated cognitive analysis

In this paper an agent-based ambient agent architecture is presented based on monitoring human's interaction with his or her environment and performing cognitive analysis of the causes of observed or predicted behaviour. Within this agent architecture, a cognitive model for the human is taken as a point of departure. From the cognitive model it is automatically derived how internal cognitive states affect human's performance aspects. Furthermore, for these cognitive states representation relations are derived from the cognitive model, expressed by temporal specifications involving events that will be monitored. The representation relations are verified on the monitoring information automatically, resulting in the identification of cognitive states, which affect the performance aspects. In such a way the ambient agent model is able to provide a more in depth cognitive analysis of causes of (un)satisfactory performance and based on this analysis to generate interventions in a knowledgeable manner. The application of the architecture proposed is demonstrated by two examples from the ambient-assisted living domain and the computer-assisted instruction domain. © 2011 The Author(s)

Formal analysis of executions of organizational scenarios based on process-oriented specifications

Abstract This paper presents various formal techniques for analysis of executions of organizational scenarios based on specifications of organizations. Organizational specifications describe (prescribe) ordering and timing relations on organizational processes, modes of use of resources, allocations of actors to processes, etc. The actual execution may diverge from scenarios (pre)defined by a specification. A part of techniques proposed in this paper is dedicated to establishing the correspondence between a formalized execution (i.e., a trace) and the corresponding specification. Other techniques proposed in this paper provide the analyst with wide possibilities to evaluate organizational performance and to identify bottlenecks and other inefficiencies in the organizational operation. For the proposed formal analysis the order-sorted predicate Temporal Trace Language (TTL) is used and it is supported by the dedicated software tool TTL Checker. The analysis approaches considered in this paper are illustrated by a case study in the context of an organization from the security domain. © Springer Science+Business Media, LLC 2009

An Agent-based Approach for Structured Modeling, Analysis and Improvement of Safety Culture

Safety culture is broadly recognized as important for operational safety in various fields, including air traffic management, power plant control and health care. Previous studies addressed characterization and assessment of safety culture extensively. Nevertheless, relations between safety culture and formal and informal organizational structures and processes are yet not well understood. To address this gap, a new, formal, agent-based approach is proposed. This paper shows the application of the approach to an air navigation service provider, including structured modeling, analysis and identification of improvement strategies for the organizational safety culture. The model results have been validated using safety culture data that had been achieved by an independent safety culture survey study. © 2011 The Author(s)