MATERIALS HANDLING SYSTEM DESIGN - Environmentally Conscious Materials Handling - page 5

6. Unit loads composed of a mix of different items are consistent with
just-in-time and/or customized supply strategies as long as item selectivity
is not compromised.

2.6 Space Utilization

Space in material handling is three-dimensional and therefore is counted as cubic
space. Effective and efficient use must be made of all available space. This is a
three-step process:
1. Eliminate cluttered and unorganized spaces and blocked aisles in work
areas (see Figure 1.2).
2. In storage areas, balance the objective of maximizing storage density
against accessibility and selectivity. If items are going to be in the ware-
house for a long time, storage density is an important consideration. Avoid
honeycombing loss (Figure 1.3). If items enter and leave the warehouse
frequently, their accessibility and selectivity are important. If the storage
density is too high to access or select the stored product, high storage
density may not be beneficial.
3. Consider the use of overhead space when transporting loads within a
facility. Cube per order index (COI) storage policy is often used in a
warehouse. COI is a storage policy in which each item is allocated ware-
house space based on the ratio of its storage space requirements (its cube)
to the number of storage/retrieval transactions for that item. Items are
listed in a nondecreasing order of their COI ratios. The first item in the
list is allocated to the required number of storage spaces that are closest
to the input/output (I/O) point; the second item is allocated to the required

Figure 1.2 Retrieving material in blocked aisles