摘要:
Cycle time and throughput of a manufacturing facility is effectively manages by a control system that employs a combination of a long-term horizon model and at least one short-term horizon model to generate control signals for a set of machines in a manufacturing facility. The long-term horizon model determines long-term average time allocation percentage for each machine for a given set of throughput targets and cycle time targets for products to be manufactured. Each of the at least one short-term horizon model determines queues for immediate use at processing tools, while the queues are subjected to a secondary adjustment based on the time allocation constraints generated by the long-term horizon model. The combination of the long-term and the at least one short-term horizon models provides a stable long-term proactive WIP bubble-management as well as short-term WIP bubble management.
摘要:
Cycle time and throughput of a manufacturing facility is effectively manages by a control system that employs a combination of a long-term horizon model and at least one short-term horizon model to generate control signals for a set of machines in a manufacturing facility. The long-term horizon model determines long-term average time allocation percentage for each machine for a given set of throughput targets and cycle time targets for products to be manufactured. Each of the at least one short-term horizon model determines queues for immediate use at processing tools, while the queues are subjected to a secondary adjustment based on the time allocation constraints generated by the long-term horizon model. The combination of the long-term and the at least one short-term horizon models provides a stable long-term proactive WIP bubble-management as well as short-term WIP bubble management.
摘要:
A method and system for integrating job shop scheduling with discrete event simulation for manufacturing facilities are provided. In one aspect a simulator simulates discrete events of a facility using a job schedule generated by a scheduler. The simulator simulates the facility based on one or more local rules, one or more resources, and one or more parameters associated with said locals rules and said resources. The simulator further models said one or more parameters as random variables and using said random variables in its simulation of the facility. The scheduler receives feedback based on output from the simulating step. The feedback includes at least an instruction to the scheduler to include at least one of said one or more resource and to change said one or more parameters based on said modeling of said one or more parameters as random variables. The scheduler uses the feedback for generating an updated schedule.
摘要:
System and method of solving, in a single-period, an optimal dispatching problem for a network of energy generators connected via multiple transmission lines, where it is sought to find the lowest operational cost of dispatching of various energy sources to satisfy demand. The model includes traditional thermal resources and renewable energy resources available generation capabilities within the grid. The method considers demand reduction as a virtual generation source that can be dispatched quickly to hedge against the risk of unforeseen shortfall in supply. Demand reduction is dispatched in response to incentive signals sent to consumers. The control options of the optimization model consist of the dispatching order and dispatching amount energy units at generators together with the rebate signals sent to end-users at each node of the network under a demand response policy. Numerical experiments based on an analysis of representative data illustrate the effectiveness of demand response as a hedging option.
摘要:
The present disclosure relates generally to systematic algorithms (and associated systems and methods) that take a forecast model as input and produce a discrete probability distribution as output, using scenario reduction ideas from stochastic programming. In one example, an algorithm (and associated system and method) creates scenarios sequentially for each time period, leading to a scenario tree.
摘要:
System and method of solving, in a single-period, an optimal dispatching problem for a network of energy generators connected via multiple transmission lines, where it is sought to find the lowest operational cost of dispatching of various energy sources to satisfy demand. The model includes traditional thermal resources and renewable energy resources available generation capabilities within the grid. The method considers demand reduction as a virtual generation source that can be dispatched quickly to hedge against the risk of unforeseen shortfall in supply. Demand reduction is dispatched in response to incentive signals sent to consumers. The control options of the optimization model consist of the dispatching order and dispatching amount energy units at generators together with the rebate signals sent to end-users at each node of the network under a demand response policy. Numerical experiments based on an analysis of representative data illustrate the effectiveness of demand response as a hedging option.
摘要:
A method, apparatus and computer program product for determining lowest cost aggregate energy demand reduction at multiple network levels such as distribution and feeder networks. An algorithm for an optimal incentive mechanism offered to energy customers (e.g. of a utility power entity) that accounts for heterogeneous customer flexibility in load reduction, with the demand response realized via the utility's rebate signal and, accounts for temporal aspects of demand shift in response for rebates. A mathematical formulation of a cost minimization problem is solved to provide incentives for customers to reduce their demand. A gradient descent algorithm is used to solve for the optimal incentives customized for individual end users.
摘要:
A method and system for integrating job shop scheduling with discrete event simulation for manufacturing facilities are provided. In one aspect a simulator simulates discrete events of a facility using a job schedule generated by a scheduler. The simulator simulates the facility based on one or more local rules, one or more resources, and one or more parameters associated with said locals rules and said resources. The simulator further models said one or more parameters as random variables and using said random variables in its simulation of the facility. The scheduler receives feedback based on output from the simulating step. The feedback includes at least an instruction to the scheduler to include at least one of said one or more resource and to change said one or more parameters based on said modeling of said one or more parameters as random variables. The scheduler uses the feedback for generating an updated schedule.
摘要:
The present disclosure relates generally to systematic algorithms (and associated systems and methods) that take a forecast model as input and produce a discrete probability distribution as output, using scenario reduction ideas from stochastic programming. In one example, an algorithm (and associated system and method) creates scenarios sequentially for each time period, leading to a scenario tree.
摘要:
A method of managing manufacturing production includes determining a plurality of products for manufacture using a production line is disclosed. Each product is specified by composition and production line steps and criteria. Production orders for products are analyzed to determine whether products should be grouped into product-types, and whether product (type) should be made-to-stock or made to order. Queuing theory based analytic methods and optimization based heuristics are used to determine the priority for each product in the production line, taking product substitution opportunities in batch-production into account. Preselected points along the production line are determined for gathering an amount of inventory for each product. This decision is made considering product-differentiation down the line. An established inventory policy for each product at preselected points along the production line requires that inventory is reviewed and an order is placed for additional inventory when on hand inventory reaches a predetermined reorder point.