International Journal of Cooperative Information Systems

In dynamic environments, changes are often unpredictable and complex. Process models cannot be fully specified up-front and process flexibility becomes a key issue. Enterprise applications and systems supporting such processes are increasingly being architected in a service-oriented style. In this light, our goal is to analyze service orchestration approaches from a process flexibility perspective. Through a systematic literature review, we evaluate 17 service orchestration approaches and analyze their support for: (i) variability, support for large collections of process variants, (ii) adaptation, need for instance changes during runtime, (iii) evolution, need for schema changes during runtime, and (iv) looseness, need for loosely-specified models. The review findings provide a clearer understanding of process flexibility requirements and service orchestration mechanisms that support them, helping us to understand the limitations and shed light on future research areas.

Concerns about energy and sustainability are growing everyday involving a wide range of fields. Even Information Systems (ISs) are being influenced by the issue of reducing pollution and energy consumption and new fields are rising dealing with this topic. One of these fields is Green Information Technology (IT), which deals with energy efficiency with a focus on IT. Researchers have faced this problem according to several points of view. The purpose of this paper is to understand the trends and the future development of Green IT by analyzing the state-of-the-art and classifying existing approaches to understand which are the components that have an impact on energy efficiency in ISs and how this impact can be reduced. At first, we explore some guidelines that can help to understand the efficiency level of an organization and of an IS. Then, we discuss measurement and estimation of energy efficiency and identify which are the components that mainly contribute to energy waste and how it is possible to improve energy efficiency, both at the hardware and at the software level.

Today there is an increase in the number of cooperative initiatives in different domains to make tools and data available to global communities free or charge. Such cooperative systems are open, heterogeneous, dynamic, and lack a formal payment system. Incentivising cooperation in these scenarios is essential to maintain their effectiveness. Therefore, there is a recognised need to move away from an ad hoc approach to one in which cooperation is supported and encouraged. The agent-oriented paradigm has been advocated as a natural way to design and implement systems that are distributed and heterogeneous. However, developing an agent-oriented system for today's cooperative systems is challenging. It requires a means not only to provide non-monetary incentives for service providers, but also to consider the level of quality of cooperations, in terms of the quality of provided and received services. In this context, the key contribution of this paper is a framework for non-monetary interactions among self-interested agents, in which the motivation to cooperate and the bases for analysing cooperations come from Piaget's theory of exchange values. Our framework includes a computational model of these values, which defines how exchange values are accumulated and spent by interacting agents. We illustrate how our framework can be used by agents to analyze cooperations and to take decisions about them, and provide an empirical evaluation.

Web service composition, that recursively constructs a composite web service out of the existing services based on a business workflow has been acknowledged as a promising approach to meet the user demands, whenever a single service alone cannot fulfil the needs. In view of frequent failures in the internet environment where the composed service is executed, reliability of the composed service must be ensured. The reliability is determined by the behavioral or transactional properties of component services. The component services for each activity of the workflow must be selected based on their behavior so that their execution results in a consistent termination. Service selection must happen at run-time in order to consider the services available in a service registry at the time of execution. Towards this need, a dynamic transaction aware web service selection approach is proposed in this paper. Further, whenever user requirements change, a long running transaction must be interrupted and cancelled which is not addressed by any of the existing works. Hence, service cancellability property is proposed in this paper and incorporated in the dynamic selection approach. The overhead of the proposed run-time selection approach is assessed and the impact of increased services on its performance is also measured.

Development of agent systems is without question a complex task when autonomous, reactive and proactive characteristics of agents are considered. Furthermore, internal agent behavior model and interaction within the agent organizations become even more complex and hard to implement when new requirements and interactions for new agent environments such as the Semantic Web are taken into account. We believe that the use of both domain specific modeling and a Domain-specific Modeling Language (DSML) may provide the required abstraction and support a more fruitful methodology for the development of Multi-agent Systems (MASs) especially when they are working on the Semantic Web environment. Although syntax definition based on a metamodel is an essential part of a modeling language, an additional and required part would be the determination and implementation of DSML constraints that constitute the (formal) semantics which cannot be defined solely with a metamodel. Hence, in this paper, formal semantics of a MAS DSML called Semantic Web enabled Multi-agent Systems (SEA_ML) is introduced. SEA_ML is a modeling language for agent systems that specifically takes into account the interactions of semantic web agents with semantic web services. What is more, SEA_ML also supports the modeling of semantic agents from their internals to MAS perspective. Based on the defined abstract and concrete syntax definitions, we first give the formal representation of SEA_ML's semantics and then discuss its use on MAS validation. In order to define and implement semantics of SEA_ML, we employ Alloy language which is declarative and has a strong description capability originating from both relational and first-order logic in order to easily define complex structures and behaviors of these systems. Differentiating from similar contributions of other researchers on formal semantics definition for MAS development languages, SEA_ML's semantics, presented in this paper, defines both static and dynamic aspects of the interaction between software agents and semantic web services, in addition to the definition of the semantics already required for agent internals and MAS communication. Implementation with Alloy makes definition of SEA_ML's semantics to include relations and sets with a simple notation for MAS model definitions. We discuss how the automatic analysis and hence checking of SEA_ML models can be realized with the defined semantics. Design of an agent-based electronic barter system is exemplified in order to give some flavor of the use of SEA_ML's formal semantics. Lessons learned during the development of such a MAS DSML semantics are also reported in this paper.