Contract Net Protocol

About: Contract Net Protocol is a research topic. Over the lifetime, 606 publications have been published within this topic receiving 13729 citations.

A dynamic scheme for scheduling complex tasks in manufacturing systems based on collaboration of agents

Abstract: The characteristics of scheduling tasks in the real world is a dynamic and challenging issue as the processes and the companies involved may change from time to time. For small flexible enterprises to respond to business opportunities, an effective scheme to facilitate dynamic coalition, share the core competencies and resources and support inter-enterprise collaboration must be developed. Although multi-agent systems (MAS) provide a paradigm for modeling these characteristics, scheduling tasks in MAS is a complex problem due to the computational complexity involved, distributed architecture for scheduling tasks by individual agents and dependency of different agents' workflows. How to develop a problem solver that can be applied in MAS to achieve coherent and consistent workflow schedules that can meet a customer's order is an important issue. In this paper, we propose a solution methodology for scheduling workflows in MAS. Our solution combines the multi-agent system architecture to dynamically discover services, workflow and activity models to specify the capabilities of agents, contract net protocol to facilitate negotiation and coordination of agents and optimization theories to optimize the cost for fulfilling an order. A problem solver for scheduling tasks in MAS has been implemented. An application scenario has also been provided to verify our solution methodology.

A hybrid and scalable multi-agent approach for patient scheduling based on Petri net models

Abstract: Scheduling patients in a hospital is a challenging issue due to distributed organizational structure, dynamic medical workflows, variability of resources and the computational complexity involved. It calls for a sustainable architecture and a flexible scheduling scheme that can dynamically allocate available resources to promptly react to patients in a hospital and deliver healthcare services timely. The objectives of this paper are to propose a viable and systematic approach to develop a scalable and sustainable scheduling system based on multi-agent system (MAS) to shorten patient stay in a hospital and plan schedules based on the medical workflows and available resources. To develop a patient scheduling system, we combine MAS architecture, contract net protocol (CNP), workflow specification models based on Petri nets and the cooperative distributed problem solving concept. To achieve interoperability and sustainability, Petri Net Markup Language (PNML) and XML are used to specify precedence constraints of operations in medical workflows and capabilities of resource agents, respectively. Agent communication language (ACL) and CNP are used to achieve communication and negotiation/mutual selection of agents. A collaborative algorithm is invoked by individual agents to optimize the schedules locally based on a problem formulation automatically obtained by Petri net models. We have developed a scheduling system based on a FIPA compliant MAS platform to solve the dynamic patient scheduling problem. To illustrate the benefit of our approach, we compare the performance of our method with a heuristic rule commonly used in practice. In addition, we also analyze and verify scalability of our approach by experiments.

Why a Cognitive Trustier Performs Better: Simulating Trust-Based Contract Nets

Abstract: We use a Contract Net protocol for comparing various strategies for trusting other agents. We introduce three classes of trustiers: a random trustier, a statistical trustier, and a cognitive trustier.

A New Modified CNP for Autonomous Microgrid Operation Based on Multiagent System

Abstract: This paper presents a new modified Contract Net Protocol (CNP) for microgrid operation based on multiagent system. The CNP is a widely used protocol for interactions among distributed problem solving. The Contract Net Interaction Protocol of the Foundation for Intelligent Physical Agents (FIPA-CNIP) is a minor modification of the original CNP for multiagent system applications. In this paper, a modified CNP (MCNP) based on the FIPA-CNIP is proposed for more specialized interactions among agents for microgrid operation. A multiagent system is designed and constructed for microgrid operation. A microgrid operation based on the multiagent system is tested to check the functionality of the proposed MCNP.

Specifying and applying commitment-based business patterns

Abstract: Recent work in communications and business modeling emphasizes a commitment-based view of interaction. By abstracting away from implementation-level details, commitments can potentially enhance perspicuity during modeling and flexibility during enactment.We address the problem of creating commitment-based specifications that directly capture business requirements, yet apply in distributed settings. We encode important business patterns in terms of commitments and group them into methods to better capture business requirements.Our approach yields significant advantages over existing approaches: our patterns (1) respect agent autonomy; (2) capture business intuitions faithfully; and (3) can be enacted in real-life, distributed settings. We evaluate our contributions using the Extended Contract Net Protocol.