According to Professor Hau Lee at the Stanford Graduate School of Business:
“The ‘bullwhip effect’ is named after the way the amplitude of a whip increases down its length — just as variations in orders tend to get amplified along the supply chain.”
Here is an example of this:
Mike wins a lottery prize and decides to spend all of it in one day. He proceeds to buy large quantities of goods from various local stores. Because of Mike’s spending blitz, the stores’ inventories are cleared out and they immediately order replacement goods plus additional safety stock from their suppliers. These suppliers in turn order replacement goods plus safety stock from their suppliers and so forth.
Each supplier along the supply chain sees an order that reflects his customer’s demand spike plus an additional amount used to pad his customer’s safety stock. Therefore, as the ordering progresses up the supply chain, they grow in size.
Because Mike spent all of his lottery winnings, he reverts back to his normal consumption pattern which leaves the suppliers up the supply chain overstocked. These overstocked suppliers then stop ordering. From the point of view of each supplier, demand has suddenly dropped far lower than normal. Just as in the above quote of Professor Hau Lee, the rise and drop off in demand increases in amplitude as one proceeds along the supply chain like the amplitude of a whip increases down its length.
The bullwhip effect occurs because each supplier reacts blindly to the demand seen from their immediate customer. This reaction is also a conservative one because each supplier sensibly adds safety stock in case the demand increase continues.
The bullwhip effect is real and enormously wasteful especially for those furthest up the supply chain. This excess inventory ties up money, warehouse space, and other resources and has a depressing effect on the businesses’ abilities to respond to demand from other customers. Manufacturers and suppliers of basic commodities are at the apex of the supply chains of many industries and are highly vulnerable to huge demand swings.
Unless your business deals directly with the ultimate consumer, your inventories and warehouse operations are also affected by the distortion of true customer demand as it makes its way up the supply chain to you. One way to combat the bullwhip effect is through the sharing of demand information along the supply chain. Accellos One’s warehouse management system has a supply chain analytics feature that makes this information sharing possible. For more information about this, please contact us.
