Abstract

Capacity planning models for tactical to operational decisions in manufacturing systems require a performance evaluation component that relates demand processes with production resources and system state. Steady-state queueing models are widely used for such performance evaluations. However, these models typically assume stationary demand processes. With shorter new product development and life cycles, increasing customization, and constantly evolving customer preferences the assumption of stationary demand processes is not always reasonable. Nonstationary demand processes can capture the dynamic nature of modern manufacturing systems. The ability to analyze dynamic manufacturing systems with multiple products and finite buffers is essential for estimating throughput rates, throughput times, and work-in-process levels as well as evaluating the impact of proposed capacity plans and resource allocations. In this article, we present computationally efficient numerical approximations for the performance evaluation of dynamic multi-product manufacturing systems with priorities and finite buffers. The approximation breaks time into short periods, estimates throughput and arrival rates based on system status and current arrival processes, and then pieces the periods together through flow balance equations. The dynamic nature of product demands is modeled through non-homogeneous Poisson processes. The performance of these approximations is presented for practically sized flowshops and jobshops.

摘要

制造系统中用于战术到运营决策的容量规划模型需要一个性能评估组件，它将需求过程与生产资源和系统状态联系起来。稳态排队模型广泛用于此类性能评估。然而，这些模型通常假设需求过程是平稳的。随着新产品开发和生命周期的缩短、定制的增加以及客户偏好的不断变化，固定需求过程的假设并不总是合理的。非平稳需求过程可以捕捉现代制造系统的动态特性。分析具有多种产品和有限缓冲区的动态制造系统的能力对于估计吞吐率、吞吐时间、和在制品水平，以及评估提议的能力计划和资源分配的影响。在本文中，我们为具有优先级和有限缓冲区的动态多产品制造系统的性能评估提供了计算效率高的数值近似。该近似将时间分解为短时间段，根据系统状态和当前到达过程估计吞吐量和到达率，然后通过流量平衡方程将这些时间段拼凑在一起。产品需求的动态特性是通过非齐次泊松过程建模的。这些近似的性能适用于实际规模的流水车间和工作车间。我们为具有优先级和有限缓冲区的动态多产品制造系统的性能评估提供了计算效率高的数值近似值。该近似将时间分解为短时间段，根据系统状态和当前到达过程估计吞吐量和到达率，然后通过流量平衡方程将这些时间段拼凑在一起。产品需求的动态特性是通过非齐次泊松过程建模的。这些近似的性能适用于实际规模的流水车间和工作车间。我们为具有优先级和有限缓冲区的动态多产品制造系统的性能评估提供了计算效率高的数值近似值。该近似将时间分解为短时间段，根据系统状态和当前到达过程估计吞吐量和到达率，然后通过流量平衡方程将这些时间段拼凑在一起。产品需求的动态特性是通过非齐次泊松过程建模的。这些近似的性能适用于实际规模的流水车间和工作车间。然后通过流量平衡方程将这些周期拼凑在一起。产品需求的动态特性是通过非齐次泊松过程建模的。这些近似的性能适用于实际规模的流水车间和工作车间。然后通过流量平衡方程将这些周期拼凑在一起。产品需求的动态特性是通过非齐次泊松过程建模的。这些近似的性能适用于实际规模的流水车间和工作车间。