A geometrical approach to computing expected cycle times for zonebased storage layouts in AS/RS

An exact, geometry-based analytical model is presented that can be used to compute the expected cycle time for a storage/retrieval (S/R) machine, executing single-commands, dual-commands, or both, in a rack structure that has been laid out in pre-specified storage zones for classes of goods. The rack may be either square-in-time or non-square-in-time. The approach is intuitively appealing, and it does not assume any certain layout shape, such as traditional 'L-shaped' class layouts. The model has been coded in Turbo Pascal, and can be used by designers as a tool for quickly evaluating alternative layout configurations with respect to expected S/R cycle time in an AS/RS, and thereby the throughput of an automated warehouse over time. This model has been successfully applied in a major manufacturing plant in Europe to evaluate reconfigurations of their rack storage layouts over the past five years.

[1]  C.-H. Wang,et al.  A framework for the dual command cycle travel time model in automated warehousing systems , 1996 .

[2]  Edward H. Frazelle,et al.  Analytical Results for Miniload Throughput and the Distribution of Dual Command Travel Time , 1991 .

[3]  Bhaba R. Sarker,et al.  Evaluation of a class-based storage scheduling technique applied to dual-shuttle automated storage and retrieval systems , 1994 .

[4]  Brett A. Peters,et al.  Analysis of dual-shuttle automated storage/retrieval systems , 1994 .

[5]  Richard J. Linn,et al.  An expert system based controller for an automated storage/retrieval system , 1990 .

[6]  Leon F. McGinnis,et al.  On Sequencing Retrievals In An Automated Storage/Retrieval System , 1987 .

[7]  Heungsoon Felix Lee.  Performance analysis for automated storage and retrieval systems , 1997 .

[8]  Meir J. Rosenblatt,et al.  A COMBINED OPTIMIZATION AND SIMULATION APPROACH FOR DESIGNING AUTOMATED STORAGE/RETRIEVAL SYSTEMS , 1993 .

[9]  Yavuz A. Bozer,et al.  Travel-Time Models for Automated Storage/Retrieval Systems , 1984 .

[10]  Abraham Seidmann,et al.  Intelligent control schemes for automated storage and retrieval systems , 1988 .

[11]  R. Meller,et al.  Multi-shuttle automated storage/retrieval systems , 1997 .

[12]  Yuehwern Yih,et al.  Using neural networks to select a control strategy for automated storage and retrieval systems (AS/RS) , 1997 .

[13]  James T. Lin,et al.  The impact of acceleration/deceleration on travel-time models for automated storage/retrieval systems , 1995 .

[14]  Stephen C. Graves,et al.  Storage-Retrieval Interleaving in Automatic Warehousing Systems , 1977 .

[15]  Pius J. Egbelu,et al.  A comparison of dwell point rules in an automated storage/retrieval system , 1993 .

[16]  Jeffrey S. Smith,et al.  Closed form models for determining the optimal dwell point location in automated storage and retrieval systems , 1996 .

[17]  SUK-HWA CHANG,et al.  Relative pre-positioning of storage/retrieval machines in automated storage/retrieval systems to minimize maximum system response time , 1997 .

[18]  Heungsoon Felix Lee,et al.  Retrieval sequencing for unit-load automated storage and retrieval systems with multiple openings , 1996 .

[19]  Bhaba R. Sarker,et al.  Travel time models in automated storage/retrieval systems: A critical review , 1995 .

[20]  SUK-HWA CHANG,et al.  Relative pre-positioning of storage/retrieval machines in automated storage/retrieval system to minimize expected system response time , 1997 .

[21]  Elsayed A. Elsayed,et al.  Order processing in automated storage/retrieval systems with due dates , 1996 .

[22]  J. M. A. Tanchoco,et al.  Performance estimation models for AS/RS with unequal sized cells , 1999 .

[23]  J. Ashayeri,et al.  A new approach for the determination of expected traveling time in an AS/RS system under any assignment policy , 1996 .

[24]  Stephen C. Graves,et al.  Optimal Storage Assignment in Automatic Warehousing Systems , 1976 .

[25]  황학,et al.  Deriving an Optimal Dwell Point of the Storage/Retrieval Machine in an Automated Storage/Retrieval System , 1992 .

[26]  Panagiotis Kouvelis,et al.  Expected travel time and optimal boundary formulas for a two-class-based automated storage/retrieval system , 1995 .