FARMS Publications

  • "Applying Tree Structure to Aggregate Scheduling in a Flexible Manufacture Environment" accepted by 27th Computer and Industrial Engineering Conference, 2000

    Author:J.Y. Zhu, A. Deshmukh, Y.Xiang and T. Middelkoop
    Abstract: This research is concerned with aggregate scheduling of a flexible manufacturing system which consists of machining and assembly subsystems where the complexity of an exhaustive search is exponential. An efficient algorithm to deal with the aggregate scheduling problem in such a flexible manufacturing systems is developed. We consider the optimal scheduling problem for a flexible manufacturing system that consists of two different machining subsystems, M_1 and M_2, and one assembly subsystem A. The three subsystems are connected by an automated guided vehicle system that is assumed always available with transportation time is included in machining time. The objective of scheduling is to minimize the makes-pan C_{max} of a product to be machined using M_1 and M_2, and assembled using A. Although the general problem of scheduling is NP complete, but certain types of scheduling problems can be solved efficiently. We show that the above aggregate scheduling problem is one of them. Our solution is based on a directed tree representation of the precedence constraints of parts and sub-assemblies of a product. Based on this tree representation, we construct scheduling algorithms that are of linear complexity. We prove that the schedule obtained is optimal.

  • "Application of Bayesian Decision Networks to Life Cycle Engineering Design" accepted by 27th Computer and Industrial Engineering Conference, 2000

    Author:J.Y. Zhu and A. Deshmukh
    Abstract: Life Cycle engineering has been strongly recommended since it is a systematic approach integrating the design and manufacture of a product with the objective of optimizing all elements involved in the life cycle of the product. Elements such as design, production, distribution, application, maintenance, disposal and recycling are considered simultaneously. It can lead to significant reduction of the cost in the product life cycle. The current lack of technology for coordinating design decisions and managing change over the life of a product creates higher costs, longer cycle time and poorer quality. Sometime, this lack of technology can be dangerous when the product involves critical missions. A decision support systems is needed for reducing the imprecision and modeling uncertainties in early design and development stages of a product. Bayesian decision theory provides a normative framework for representing and reasoning with decision problems under uncertainty. This research investigates the possibility and benefits of applying Bayesian decision networks to life cycle engineering design of a product. We study how to specify a domain model, an action model and a utility model, and how to compute the optimal decision sequence in the form of a policy.
    Postscript: ciec-01.ps PDF: ciec-01.pdf

  • "Emergent Aerospace Designs Using Negotiating Autonomous Agents" in Proceedings of NATO RTO Meeting, AVT-029, 1999

    Author:Abhi Deshmukh, Anjaneyulu Krothapalli, Tim Middelkoop, and Chuck Smith
    Abstract: This paper presents a distributed design methodology where designs emerge as a result of the negotiations between different stake holders in the process, such as cost, performance, reliability, etc. The proposed methodology uses autonomous agents to represent design decision makers. Each agent influences specific design parameters in order to maximize their utility. Since the design parameters depend on the aggregate demand of all the agents in the system, design agents need to negotiate with others in the market economy in order to reach an acceptable utility value. This paper addresses several interesting research issues related to distributed design architectures. First, we present a flexible framework which facilitates decomposition of the design problem. Second, we present overview of a market mechanism for generating acceptable design configurations. Finally, we integrate learning mechanisms in the design process to reduce the computational overhead.
    Postscript: avt-nato-06.ps.gz PDF: avt-nato-06.pdf



  • "Optimal Frozen Period in Supply Chains with Updateable Demand Forecasts" in the Proceedings of 15th International Conference on Production Research, 1999

    Author:Zhaotong Lian, Abhijit Deshmukh and Jin Wang
    Abstract: We consider a periodic auditing model for manufacturers in a supply chain, who observe stochastic demand, proportional holding/expedited ordering costs, and setup cost. Customer demand for a component can arrive in any time unit, but the procurement quantities are determined every T time units, which is defined as a frozen period. The demand forecasts are updated every time as more information becomes available from the marketplace. This paper proposes a new ordering policy and compares it with the current practices in industry. Our objective is to determine the optimal length of a frozen period and the ordering quantity of each unit time in a frozen period such that the expected total cost per unit time is minimized.
    Postscript: irelandpaper2.ps



  • "Strategic Coalition Formation in Supply Chains" in the Proceedings of 15th International Conference on Production Research, 1999

    Author:Naga Krothapalli and Abhijit Deshmukh
    Abstract: Coalition formation represents a strategic decision made by individual suppliers in order to satisfy customer demand which cannot be met individually. We study the behavior of supply chain coalitions by applying models developed in the context of economic systems. We discuss the implications of these models on the size and stability of different coalitions in supply chains. Study of coalitions is of importance in supply chains where the overall cost and delivery performance are a function of the capabilities of suppliers at each stage of the network.
    Postscript: ICPR99a.ps



  • "Caution! Agent Based Systems in Operation" in InterJournal, 1999

    Author:Tim Middelkoop and Abhi Deshmukh
    Abstract: As agent based systems move out of the controlled laboratory and simulated environment into real world applications, they face significant design and operational challenges. This paper attempts to highlight some of the major issues involved in the design and implementation of agent based applications. Our intent is not to prescribe specific solutions or actions, which will depend on the application domain, scope and resources available, but to make the reader aware of the issues which need serious consideration when using agents to tackle real world problems.
  • Version 2
    HTML: caution-02 Postscript: caution-02.ps.gz PDF: caution-02.pdf
  • Version 1
    HTML: caution-01 Postscript: caution-01.ps.gz



  • "Multi-Agent Design Architecture for Integrated Design Systems" in AIAA Journal of Aircraft, Accepted with revisions, Jan. 1999

    Author:A. Deshmukh, T. Middelkoop, A. Krothapalli, W. Shields and C. A. Smith
    Abstract: Integrated Design Systems (IDS) represent integration of broad range of high fidelity knowledge from expert sources in near real time to synthesize and refine design and product realization. Such a system should result in an order of magnitude reduction in product realization time. The characteristics of IDS are: coordination of asynchronous design activities; conflict management; and interoperability among heterogeneous software and hardware environments to accomplish an effective collaborative computational system.
    Multi-Agent Design Architecture (MADA), described in this paper, is designed to address the above requirements and provide additional features. This architecture provides seamless integration of product realization activities across heterogeneous machines, computing platforms, programming languages, data and process representations using distributed intelligent agents. An agent in the context of MADA is an autonomous computational entity which is capable of migrating across computing environments asynchronously. These agents posses intelligence in the form of individual goals, beliefs and learning mechanisms, and interact cooperatively to accomplish overall IDS objectives. This paper presents an application of the MADA model to the design of aerospace components. Specifically, we demonstrate the use of integrated design and analysis tools for creating a High Speed Civil Transport exhaust nozzle.
    Postscript: aiaa_aircraft.ps.gz



  • "Design of Negotiation Protocols for Multi-Agent Manufacturing Systems," in International Journal of Production Research, vol. 37, no. 7, 1601-1624, 1999

    Author: Naga Krothapalli and Abhijit Deshmukh
    Abstract: This paper proposes new inter-agent and intra-agent negotiation mechanisms for improving the performance of multi-agent or decentralized manufacturing systems. The overall performance of this system depends on the effective interactions between agents. This research presents methods which would permit cooperation and multi-stage interactions among agents. Agents may collaborate or preempt other agents based on the available currency and task criticality. The objective of this research is to demonstrate the efficiency of different negotiation and collaboration schemes between agents of the same class (parts, machines, etc), and inter-class negotiations using currency metrics and preemption. The proposed negotiation schemes are implemented using the Swarm simulation platform.
    Postscript:IJPR97.ps



  • "Complexity in Manufacturing Systems: Part 1: Analysis of Static Complexity," in IIE Transactions, vol. 30, no. 7, 1998

    Authors:A. Deshmukh, J. Talavage and M. Barash
    Abstract: This paper studies static complexity in manufacturing systems. We enumerate factors influencing static complexity, and define a static complexity measure in terms of the processing requirements of parts to be produced and machine capabilities. The measure suggested for static complexity in manufacturing systems needs only the information available from production orders and process plans. The variation in static complexity is studied with respect to part similarity, system size, and product design changes. Finally, we present relationships between the static complexity measure and system performance.
    Postscript: iie_trans.ps.gz



  • "Multi-Agent Design Architecture for Integrated Design System," in 36th AIAA Aerospace Sciences Meeting, Jan. 1998

    Author:A. Deshmukh, A. Krothapalli, T. Middelkoopi, W. Shields and C. A. Smith

    Postscript: pre-aiaa_journal.ps.gz



  • "Mobile Agents for Collaborative Design and Analysis," in 1997 International CIRP Design Seminar,Oct. 1997

    Author:T. Middelkoop and A. Deshmukh
    Abstract: As the tools for design and manufacturing increase in both numbers and sophistication, the ability to collaborate using these tools effectively is becoming increasingly difficult. In order to use high fidelity analysis and manufacturing tools at the design stage, the designers need to communicate with domain experts and their tools, which may be geographically dispersed over heterogeneous computing platforms. The ability to effectively communicate between diverse tools is thus strewn with technical difficulties and ontological issues, which impede the collaborative process.
    This paper presents a Multi Agent Design Architecture (MADA) model which provides a framework for the design and analysis tools to effectively communicate by enlisting the use of mobile software agents.
    Postscript:mada-conf01.ps.gz



  • "Self-Regulating Negotiating Schemes for Robust Agent-Based Manufacturing Systems," in Proceedings of the 7th Industrial Engineering Research Conference, 1998

    Author: Naga Krothapalli and Abhijit Deshmukh
    Abstract: Agent-based manufacturing systems offer several advantages over hierarchically organized systems. However, performance of agent-based systems has been a major concern which has hampered widespread acceptance of these systems. Several researchers have noted that the performance of agent-based systems is highly sensitive to the bidding or negotiation protocols used. In this paper, we study the robustness of system performance measures with respect to the negotiation protocols used by the individual agents. We propose self-regulating negotiation schemes which prevent the agents from ``price'' or ``utility'' cascades. The core of the self-regulatory mechanism lies in a dynamic utility curve, which is based on the current state and the past history of the agent.
    Postscript:IERC98.ps



  • "Effects of Negotiation Mechanisms on Performance of Agent Based Manufacturing Systems," in Proceedings of 7th International Conference on Flexible Automation and Intelligent Manufacturing, 1997.

    Author:Naga Krothapalli and Abhijit V. Deshmukh
    Abstract: This paper proposes new inter-agent negotiation mechanisms for improving the performance of agent based or decentralized manufacturing systems. The focus of this paper is on demonstrating efficiency of different negotiation and collaboration schemes between agents of the same class (parts, machines, etc) and inter-class negotiations using currency metrics. The cooperation and negotiation protocols are modeled using the Swarm multi-agent simulation platform. We demonstrate the robustness of the proposed schemes, and compare them with hierarchical scheduling systems.
    Postscript:FAIM97.ps



  • "Rapid Deployment of Agents to Facilitate Collaborative Engineering," in Proceedings of International CIRP Design Seminar: Multimedia Technologies for Collaborative Design and Manufacturing, 1997

    Author:Tim Middelkoop, Naga Krothapalli, Abhijit V. Deshmukh and James Solberg
    Abstract: This paper presents a framework for rapid development of interfaces between software tools, which are distributed over heterogeneous platforms, to facilitate collaboration between organizations. We describe a Rapid Agent Deployment Architecture (RADA) for designing autonomous, mobile agents, which serve as links between software products. RADA is a third-party service which allows the two (or more) potential collaborators to interact over the internet using shared white-boards. Each participant subscribes to the service and specifies the input and output parameters for the software tools. The shared white-board provides a medium for resolving ambiguities regarding the references and units. RADA creates a Java based agent capable of handling the specified interaction. The agent has limited intelligence for converting units and using standard translators. These agents reside at the RADA client sites and can be invoked manually or periodically.
    This paper demonstrates the use of RADA methods for a Multi-Agent Design Architecture (MADA). MADA is a federation of design and analysis tools, which allows the integration of high fidelityknowledge at the design stage. We demonstrate the effectiveness of RADA for integrating tools in MADA.
    Postscript:CIRP97.ps






    • FARMS Presentations

  • "Agents and Electronic Commerce", Presented at DCSB July 6, 1999.

    Author:Tim Middelkoop
    Slides: online version



    • FARMS
    Last modified: Thu Jan 27 10:11:39 EST 2000