The document discusses the bullwhip effect, which occurs when demand fluctuations are amplified up the supply chain. It provides the example of Procter & Gamble observing that distributor orders to factories for disposable diapers varied more than retail demand, and factory orders from distributors varied even more. This occurred even though demand for diapers is very consistent. The bullwhip effect causes inefficiencies like excess costs and variability in production and shipping. Ways to remedy it include improving demand forecasting, reducing order batching, and increasing communication between supply chain partners.

1. Bullwhip Effect
BUSM 361 Sec. 2
November 28, 2005
Jeremy Leishman
Jed Robison
Chris Rogers
Sarajane Zarbock

2. What is the Bullwhip Effect?
The bullwhip effect is the magnification of demand fluctuations, not the
magnification of demand. The bullwhip effect is evident in a supply chain when demand
increases and decreases. The effect is that these increases and decreases are exaggerated
up the supply chain.
The essence of the bullwhip effect is that orders to suppliers tend to have larger
variance than sales to the buyer. The more chains in the supply chain the more complex
this issue becomes. This distortion of demand is amplified the farther demand is passed
up the supply chain.
Proctor & Gamble coined the term “bullwhip effect” by studying the demand
fluctuations for Pampers (disposable diapers). This is a classic example of a product with
very little consumer demand fluctuation. P&G observed that distributor orders to the
factory varied far more than the preceding retail demand. P & G orders to their material
suppliers fluctuated even more.
Babies use diapers at a very predictable rate, and retail sales resemble this fact.
Information is readily available concerning the number of babies in all stages of diaper
wearing. Even so P&G observed that this product with uniform demand created a wave
of changes up the supply chain due to very minor changes in demand.
Example of the Bullwhip Effect
Re tail Orde r s to Dis tr ibutor
40000
35000
30000
e ad
25000
D mn
20000
15000
10000
5000
0
1 2 3 4 5 6 7 8 9 10 11 12
M onths

3. Dis tributor Or de r s to Factor y
40000
35000
30000
e ad
D mn
25000
20000
15000
10000
5000
0
1 2 3 4 5 6 7 8 9 10 11 12
M onths
The graphical representations above show the bullwhip effect between two supply
chain partners. It can be seen that the Distributor orders to the factory experience
demand fluctuate far more drastically than the retail demand. Over time as the
Distributor builds inventory and fulfills orders, it communicates very different demand
levels to the upstream factory by the order amounts it requests. This becomes more
complicated the farther up the supply chain we go. Some of the reasons that the bullwhip
effect occurs include the following:
• Over reacting to the backlog orders.
• Little or no communication between supply chain partners.
• Delay times between order processing, demand, and receipt of products.
• Order batching: method for reduction of ordering costs due to price discounts for
bulk ordering, transportation expense decrease by ordering full-truck loads, etc.
• Limitations on order size (i.e. retailers can order products in cases of 10 from
wholesaler; however, distributors receive orders in cases of 1,000)
• Inaccurate demand forecasts.
• Free return policies.

4. How do costs increase?
Excess raw materials costs arise from the last minute purchasing decisions made
to accommodate an unplanned increase in demand. The result of these panicked buying
periods is an inventory of unused supplies. As these unused supplies grow, so do the
associated costs.
Excess capacity during periods of low volume of demand is followed by
inefficient utilization and overtime expenses incurred during high demand periods. This
is made worse by the excess warehousing expenses that are incurred because of unused
storage space, as well as increases in shipping costs caused by premium rates paid for last
minute orders..
How to remedy the Bullwhip Effect
When the bullwhip effect is first identified in a supply chain, it is important to
identify the problem areas. The following areas are places in the supply chain that should
be considered when trying to decrease the bullwhip effect. Although many of these areas
many seem like proper business practices, the reality is that they diminish the efficiency
of the supply chain. Once changes are made in these areas, the productivity and
timeliness of the supply chain will increase greatly and the bullwhip effect will be
dramatically lessened.
1. Demand Signal Processing
• Retailers often use realized demand as an indicator of future demand.
• Inference and data dependency problems.
2. Rationing Gaming
• Used when demand outstrips supply.

5. • Rationing might indicate internal problems that limit meeting supply goals.
3. Order Batching
• Used because organizations are attempting to obtain benefits from large-volume
pricing discounts and reduced costs of transportation.
• Can lead to large inventory volumes and misleading demand figures for upstream
suppliers.
4. Price Variations
• Used to position suppliers that are involved in market share wars with other suppliers.
• Might cut off established relationships in efforts to “shop around” for a better price.
Where to get more information
An extensive amount of research has been completed on what causes the bullwhip
effect and how to remedy the problems it causes. The following is a list of resources
where more information can be found on this topic:
Baganha, M. and M. Cohen (1998) “The Stabilizing Effect of Inventory in Supply
Chains,” Operations Research.
Baljko, J. (1999a) “Expert Warns of ‘Bullwhip Effect’,” Electronic Buyers’ News, July
26.
Cachon, G. (1999) “Managing supply chain demand variability with scheduled ordering
policies,” Management Science.
Cachon, G. and M. Fisher (2000) “Supply Chain Inventory Management and the Value of
Shared Information,” Management Science.
Cachon, G. and M. Lariviere (1999) “Capacity Choice and Allocation: Strategic Behavior
and Supply Chain Performance,” Management Science.

6. Bibliography
Lee, H., P. Padmanabhan and S. Whang (1997) “Information Distortion in a Supply
Chain: The Bullwhip Effect,” Management Science, 43, 546-558.
Croson, Rachel; Donohue, Karen; Katok, Elena; Sterman, John (2003) “Supply Chain
Management: A Teaching Experiment,” Second Asian Conference on Experimental
Business Research.