Replenishing Dependent Demand

Abstract

Dependent demand differs from independent demand in that it is related to the demand of another item, or items, rather than to the independent demand of the marketplace. Items causing the demand are called parents of the dependent demand items (or components). A bicycle can be the independent demand (the parent) of the frame (the component). The frame, in turn, is considered the parent of the aluminum tubing which is a component of the frame. The demand of the frame is dependent on the bicycle and the demand of the aluminum tubing is dependent on the frame. If the bicycle is assembled in lots of 100 every 2 weeks, the demand for the frame is 100 every 2 weeks. If the frame is fabricated in lots of 250 every 5 weeks, the demand for the tubing will be the quantity of tubing required to make 250 frames every 5 weeks. The above relationship are as follows:

• − One (1) bicycle

  • — Independent demand = 10/ day

  • — Assembly =100/2 weeks

• − One (1) frame/ bicycle

  • — Dependent demand =100/2 weeks

  • — Fabrication/ 250/5 weeks

• − 10 feet tubing/ frame

  • — Dependent demand = 2,500 feet/ 5 weeks

  • — Purchasing lot = 10,000 feet/ 20 weeks