(A) study on the economic design of refrigerated automated storage and retrieval systems

Abstract

The objective of this thesis is the development of a design model for refrigerated automated storage and retrieval systems(R-AS/RS). Compared with ordinary unit-load AS/RS, R-AS/RS have several different design and operating characteristics as the followings : 1) A more emphasis is given on the storage function and so it has two-depth deep lane in the storage rack. 2) Cooling units are required to maintain cold temperature in the system. 3) The Maximum storage orders handled per unit time depends on the system capacity. Considering the above characteristics we formulate the design problem as a non-linear mixed integer programming whose objective is to minimize the sum of the construction cost and the storage-capacity shortage cost. The decision variables are the storage volume, the number of storage and retrieval (S/R)machines, the capacity of cooling units, and the physical configuration of the building. A case problem is solved to illustrate the model.