Stephen J. Buckley

Fast motion planning for multiple moving robots

The author presents an efficient solution to the motion-planning problem for multiple translating robots in the plane. It is shown that careful priority assignment can greatly reduce the average running time of the planner. A priority assignment method is introduced which attempts to maximize the number of robots which can move in a straight line form their start point to their goal point, thereby minimizing the number of robots for which expensive collision-avoiding search is necessary. This prioritization method is extremely effective in sparse workspaces where the moving robots are the primary obstacle.<<ETX>>

Experience using the IBM supply chain simulator

The IBM Supply Chain Simulator (SCS) is a software tool that can help a company or a group of companies make strategic business decisions about the design and operation of its supply chain. SCS and its predecessors were originally developed by IBM Research to improve IBMs internal supply chains. The tool has played an important role in the resurgence of IBM over the last six years (1992-8). In 1997 the IBM Industry Solution Units began using the tool to help its clients improve their supply chains. After about a year of business, successful engagements have been completed in a variety of geographies and business segments. SCS deploys a mix of simulation and optimization functions to model and analyze supply chain issues such as site location, replenishment policies, manufacturing policies, transportation policies, stocking levels, lead times, and customer service. The paper reviews the capabilities of SCS and presents experience from practical studies.

Distributed supply chain simulation in a DEVS/CORBA execution environment

The emerging electronic commerce and rapidly changing business environments place strong requirements on a next-generation supply-chain analyzer to simulate the flow of goods through the entire supply chain in a timely manner. Such requirements include scalable and efficient model execution and support for flexible future extensibility based on an open industry standard. This paper presents design considerations for a supply chain modeling and simulation environment to execute in a parallel and distributed manner on a DEVS/CORBA run time infrastructure. We recall that DEVS (Discrete Event System Specification) is a sound formal modeling and simulation framework based on generic dynamic systems concepts that can integrate into a parallel and distributed run time infrastructure. CORBA (Common Object Request Broker Architecture) is an open standard that is rapidly gaining universal business acceptance. It can be employed as middleware to support a heterogeneous, network-centric, distributed computing environment that includes modeling and simulation as well as other business objects. Implementing a distributed supply chain simulator in a DEVS/CORBA execution environment not only may significantly improve execution speed but also may provide an advanced supply chain model development capability based on the DEVS modeling and simulation framework.

Panel session: opportunities for simulation in supply chain management

It has become a matter of survival that many companies improve their supply chain efficiency. This presents an opportunity for simulation. However, there are many challenges that must be overcome for simulation to be a contributor to play an effective role. Four contributors discuss the opportunities that they see for simulation to play a meaningful role in the area of supply chain management.

Planning Compliant Motion Strategies

This paper describes a planning program that synthesizes compliant motion strategies, in which an object in the grasp of a robot slides along obstacles, in an attempt to reach a goal region. The input to the planner is a model of the task geometry, a start region, and a goal region. To make the planning problem tractable, we reduce the task geometry to a finite state space, whose states are collections of vertices, edges, and faces from the configuration space of the robot. Strategy synthesis is complicated by uncertainty in the start ing configuration of the robot and in robot sensing and con trol. The planner synthesizes compliant motions that are guaranteed to perform state transitions despite uncertainty. Using best first search, compliant motions are synthesized until a strategy is found from the start state to a goal state. A strategy may require that the robot stop in an intermediate state, using sensors to determine the next commanded motion.

A technical framework for sense-and-respond business management

In this paper we present a technical framework that supports sense and respond (SaR), the approach that enables an enterprise to adapt to a rapidly changing business environment. To implement the SaR approach, an enterprise proactively monitors trends and uses effective decision-support tools to help it act in a timely manner. We describe two pilot projects in which we implemented SaR prototypes and applied them to solve business problems. In the first pilot project we helped the IBM Microelectronics Division deploy an automated inventory management system based on our inventory optimization model. In the second pilot project, we helped the IBM Personal Computing Division deploy a SaR system in support of demand/supply conditioning. One of the components of this SaR system is an order trend model that provides early warning of constraints and excesses in the supply chain and helps make demand/supply conditioning more effective. Early results from these projects are encouraging and show that significant gains in profitability are possible.

An integrated and adaptive decision-support framework for high-tech manufacturing and service networks

This article gives an update on a major international collaborative project under the integrated manufacturing and service systems initiative pursued by the Agency for Science, Technology and Research in Singapore. The objective of the project is to investigate how design, analysis, enhancement and implementation of critical business processes in a manufacturing and service network can be realized using one single simulation/application framework. The overall architecture of the framework outlines how commercial simulation packages and web service-based business process application components can be connected through a commercial application framework to achieve maximum leverage and re-usability of the application components involved. The project also addresses research issues with regard to mechanisms for interoperation between commercial simulation packages, symbiotic interaction between simulation-based decision support components and physical systems, and simulation speed-up through multi-objective optimal computing budget allocation techniques on a grid/cluster infrastructure.

Symbiotic simulation for business process re-engineering in high-tech manufacturing and service networks

In todays highly competitive business environment, the speed of a companys response to changes by adapting its own business processes is vital to its survival. In this paper, we propose a symbiotic simulation system that can monitor the real-world operations of high-tech manufacturing and service networks, carry out what-if analysis and optimization on service-oriented based business workflow, and dynamically deploy the optimized business workflow onto the real-world operations. A case study of an aerospace spare parts logistics system was carried out to investigate the viability of the system.

Utilizing simulation to evaluate business decisions in sense-and-respond systems

Simulation can be an effective way to evaluate alternative decisions in sense-and-respond systems prior to taking actions to resolve existing or anticipated business situations. In sense-and-respond systems, business situations arise within predefined contexts that specify what aspects of the business need to be monitored and what information is needed to make decisions. We have designed a decision support system that dynamically configures simulation models based on business context and interactively presents simulation results to business analysts. In this paper, our decision support system is applied to the IBM demand conditioning process, in which mismatches between supply and demand are identified and corrective actions are initiated.

On optimizing the selection of business transformation projects

To compete and thrive in a changing business environment, a business can adapt by initiating and successfully carrying out business transformation projects. In this paper we propose a methodology for the optimal selection of such transformational projects. We propose a two-stage methodology based on (1) correlation analytics for identifying key drivers of business performance and (2) advanced portfolio-optimization techniques for selecting optimal business-transformation portfolios in the face of resource constraints, budget constraints, and a rich variety of business rules. We illustrate our methodology through a case study from the electronics industry.