Due to demanding service levels in e-commerce order fulfillment, modeling and analysis of integrated storage picking processes warehouses deserve special attention. The upstream system can have a significant impact on the performance downstream process. With particular focus multiline orders, we develop an analytical framework for (shuttle-based retrieval system) (pick networks. To capture cons...

This paper discusses pertinent issues in applying CONstant Work-In-Process (CONWIP) principles to control shop ̄oor operations in a manufacturing environment characterized by several product families processed along di€erent routes in several production cells. The approach we take is to simultaneously answer two major questions: (1) what is the best WIP level? and (2) how to arrange the backlog ...

Closed Queueing Networks are used in modeling various systems such as FMS, CONWIP Material Control, Computer/Communication Systems, and Health Care. Mean Value Analysis (MVA) is often used to compute the performance measures for these models. For networks with multiple-server stations, the exact MVA algorithm becomes computationally complex and existing approximations introduce high errors. The...

In numerous wafer fabrication facilities (wafer fabs) the load changes dynamically. Current load release control schemes are usually developed and tested in a constant load environment. In this paper, we discuss four CONWIP-like lot release policies and assess their ability to buffer variability generated by the load changes and to keep the lot release variability as low as possible. All contro...

This paper analyzes a proposed release control methodology, WIPLOAD Control (WIPLCtrl), using a transfer line case modeled by Markov process modeling methodology. The performance of WIPLCtrl is compared with that of CONWIP under 13 system configurations in terms of throughput, average inventory level, as well as average cycle time. As a supplement to the analytical model, a simulation model of ...

This paper presents a model for an unreliable production line, which is operated according to demand with constant work-in-process (CONWIP). A simulation model is developed based on the discrete model and several case problems are analyzed using the model. The model is utilized to optimize storage space capacities at intermediate stages and the number of kanbans at the last stage, which is used...