ORDER PICKING OPTIMIZATION

Chapter eight RightPick RightShip: Order Picking and Shipping

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Table 8.4 RightSlot Statistics and Formulas

Slotting Statistic

Unit(s) of Measure

Symbol

Notes and Comments The time period for slotting calculations

Slotting period

R

Time (year, quarter, month, week, day)

Popularity

P

Requests per period

Sometimes referred to as the hits on an item; used with volume to determine assignment to a storage mode and location within the storage mode Sometimes referred to as the demand for an item; used with unit cube to compute cube movement for storage-mode assignment and space allocation Measures the physical size of one unit of a unique item; the information may already be in a database; if not, C can be computed by measuring the size of the outer container for the item (e.g., pallet, case, tote, bag, etc.) and dividing by the number of units in the container Sometimes referred to as the volume ; used to determine the appropriate storage mode and the allocation of space in the storage mode Used in golden zoning; the items with the highest pick density should be assigned to the most accessible picking locations

Turnover

T

Units shipped per period

Unit cube

C

Cubic feet per unit

Cube movement

V = T × C

Cubic feet per period

Pick density

D = P / V

Requests per cubic foot

Demand increment Demand correlation Standard deviation of demand

I = T / P

Units per request

—

DC ij

—

The probability that item i will appear on an order when item j does Measure of the daily standard deviation of demand

S

—

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