Optimal design of rack structure with modular cell in AS/RS

A survey of literature on automated storage and retrieval systems

“…unit load Houshyar and Chung (1991) unit load x Taboun and Bhole (1993) unit load x x Randhawa and Shroff (1995) unit load x x x x unit load x Potrč et al (2004) unit load and multi shuttle x x simulation and analytical Rosenblatt et al (1993) unit load x x x x analytical Karasawa et al (1980) unit load x x Zollinger (1982) unit load x x Ashayeri et al (1985) unit load x Azadivar (1987) unit load x Bozer and White (1990) end-of-aisle miniload x Van Oudheusden and Zhu (1992) person-on-board x Bozer and White (1996) end-of-aisle miniload x x Chang and Wen (1997) unit load x Hwang and Ko (1998) unit load x x Park et al (1999) end-of-aisle miniload x Malmborg (2001a) unit load x x Malmborg (2001b) multi shuttle Malmborg (2002 and2003a) autonomous vehicle S/R x x Koh et al (2005) end-of-aisle miniload x Lee et al (2005) unit load x Table 2: Overview of research in design models that can assist in decision making for physical design in combination with control issues.…”

A simulation-optimization heuristic for configuring a selective pallet rack system

“…In column (5) is shown the estimated value of E[F(Π f )] and in column (6) the run time (in seconds) required by the algorithm to terminate. [2,3,3,3,3,3,3,3,3,3,3] 0.9499 41.46 20 11 [2,3,3,3,3,3,3,3,3,3,3] The inspection of Table 2 reveals that the initial solutions report point estimators of E[F(Π 0 )] that are often close to the objective value of F e = 0.90. Consequently, the number of banks that are needed in order to reach this objective is low, as presented in Table 3.…”

“…In reference [1] the authors introduced the idea of an AS/RS with racks of unequally sized cells or slots, and developed a model for estimating the performance of such an AS/RS under random storage assignment. In reference [2] the authors proposed a model to design an AS/RS with modular cell racks which allows for cells of different sizes. In this work a mixed integer non-linear program was proposed to find the cell size that minimizes the total unused space assuming random storage assignment.…”

“…Because of the design of the solution approach, a solution may have banks with different configurations, but within each bank the load beams are evenly spaced; this is, the distance between consecutive load beams is equal. Consequently, we chose to represent the final solution as a one-dimensional array of the form Π f =[l 1 , l 2 , …] where l k is the number of evenly spaced load beams installed in bank k.…”

“…The instance index is shown in column (1) while the number of banks in the final solution is presented in column (2). Column (3) presents the solution reported by the simulation-optimization heuristic (i.e.…”