An AI approach for scheduling space-station payloads at Kennedy Space Center

The Payload Processing for Space-Station Operations (PHITS) is a prototype modeling tool capable of addressing many Space Station related concerns. The system's object oriented design approach coupled with a powerful user interface provide the user with capabilities to easily define and model many applications. PHITS differs from many artificial intelligence based systems in that it couples scheduling and goal-directed simulation to ensure that on-orbit requirement dates are satisfied

Knowledge Organization and Inference Engine for the WVU Face Decision Support System

The knowledge-based organization for the West Virginia University Face Decision Support System is given, along with the initial development of the associated inference engine. The knowledge base contains generic knowledge about underground coal mines that utilize continuous miners. A typical knowledge entry is given, and the inference engine methodology is explained. The engine utilizes this knowledge with data from monitoring systems and from interaction with the section foreman, to assist in making section management decisions and plans

Multi-agent based beam search for intelligent production planning and scheduling

Production planning and scheduling is a long standing research area of great practical value, while industrial demand for production planning and scheduling systems is acute. Regretfully, most research results are seldom applied in industry because existing planning and scheduling methods can barely meet the requirements for practical applications. This paper identifies four major requirements, namely generality, solution quality, computation efficiency, and implementation difficulty, for practical production planning and scheduling methods. Based on these requirements, method, a multi-agent based beam search (MABBS), is developed. It seamlessly integrates the multi-agent system (MAS) method and beam search (BS) method into a generic multi-stage multi-level decision making (MSMLDM) model to systematically address all the four requirements within a unified framework. A script language, called EXASL, and an open software platform are developed to simplify the implementation of the MABBS method. For solving complex real-world problems, an MABBS-based prototype production planning, scheduling and execution system is developed. The feasibility and effectiveness of this study is demonstrated with the prototype system and computation experiments. © 2010 Taylor & Francis.postprin

A Comparison of Alphanumeric, Direct Manipulation Graphic, and Equivalent Interface Design for a Production Scheduling Task

Scheduling is an essential factor influencing the efficiency of any production system. The effectiveness of the scheduling system depends upon the interaction of the human and machine. Thus, to effectively design the interface between the human and the machine, the human factors professional must understand scheduling behavior and the information requirements of the scheduling task. The present study modeled human scheduling behavior and determined the information requirements of the scheduling task. The study also compared alphanumeric, direct manipulation graphic, and equivalent interfaces to determine which interface best supports scheduling. The results of the study show that schedulers monitor the current system state and preview to future system states to test scheduling options and make scheduling decisions. Thus, current state, goal state, future state, and discrepancy between goal state and future state information help schedulers. In addition, the analysis suggests that a mixed format interface design best supports the human in the scheduling system. Recommendations for interface design and future research are discussed

Optimization of facility layout

Computer-aided layout technique, which appears to be the best approach to solving complex layout problems, is not commonly used in practice. One of the important reasons may be the generation of unrealistic layouts which results from ignoring the important practical constraints and objectives involved in layout problems. As one possible solution to this problem, a human planner can develop layout using a computer routine with those constraints and objectives in mind. However, the development of a heuristic procedure which incorporates human-like layout processes into a computer program could be a better solution;This dissertation provides the means of a realistic or a close to realistic layout development using important practical objectives and constraints involved in facility layout. Instead of ignoring those factors due to the difficulties of implementing them into mathematical statements, using them in the process of layout development will be helpful to reach an optimum or a near-optimum solution;An experimental system, FLUKES, has been constructed for testing purposes. This system develops layouts which include the practical factors involved in layout problems. These factors include architectural limitations, health/safety, user preferences, utilities, department shapes, future expansion plans, and energy savings as well as material handling costs. FLUKES uses these factors not only for the evaluation of a layout, but also for the search for a solution

Design and implementation of a production scheduling system for continuous manufacturing environment

Scheduling a continuous manufacturing flow shop environment with several machines, stochastic arrival of demands, different product requirements and limited resources is a complex task. This research develops a methodology for scheduling products in glass fiber industry. The system consists of two components. An optimizing linear program determines the optimal solution for a sub-problem that accounts for safety stocks, demands, machine capacities, and due dates. The job queues from the LP model are then sequenced based on 'earliest job due date' for machines that have two or more jobs to be performed on the same time. This sequenced solution is then input to a simulation model. The simulation model prioritizes the queue of jobs on each machine so that minimum rate of change of throughput is achieved, while satisfying the due dates. The model was validated for a major fiber galss manufacturer. The results show that the use of an integrated optimizing and heuristic solution system provides better results than current scheduling practice in terms of machine utilization, deviations from target inventories, and on-time jobs

An Expert system for flexible manufacturing system scheduling : knowledge acquisition and development

Expert systems have been suggested as a solution for difficult problems, including FMS scheduling. As one of the aspects of artificial intelligence (AI), expert systems have achieved considerable success in recent years in medical science, chemistry, and engineering. However, building an expert system is a difficult task, the most crucial problem being that of knowledge acquisition. Obtaining expert knowledge is a difficult and time-consuming process. Moreover, since FMSs represent a relatively new technology, experts capable of FMS planning and scheduling are generally unavailable. One possible solution for this problem is to train a non-expert operator, allow the operator to practice with a simulated system and accumulate experience, and then build an expert system using the newly acquired knowledge. To this end, an interactive graphic simulation method for the effective utilization of human pattern-recognition ability is proposed. Once the required knowledge is elicited through an interactive graphic simulation model, an expert system is developed from acquired rules. The method includes an FMS simulation model, a Gantt chart-based schedule, a simulator, an expert system, and a human operator. First, an initial schedule is simulated, utilizing the expert system to determine the loading sequence and a dispatching rule. The schedule is then updated by an expert system and/or human operator with the capability of maximizing schedule objectives, while at the same time saving reasons for changes as new production rules, which are subsequently generalized and added to the expert system knowledge base. The system is implemented in Smalltalk/V on an IBM PC/AT and the implementation is based upon a detailed sample problem. It was determined that a human operator can obtain near-optimum schedules in short time periods, at the same time gaining valuable experience in use of the scheduling process. Furthermore, it was determined that this model can be a useful training device for inexperienced operators and a time-saving decision-making aid for expert schedulers

Uma abordagem híbrida do problema da programação da produção através dos algoritmos simulated annealing e genético /

Tese (Doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico