The bullwhip effect describes which phenomenon?

• A. Small demand changes create large variations upstream in the supply chain.
• B. Demand changes are dampened downstream.
• C. Only forecast errors cause supply chain changes.
• D. Lead times become shorter as demand increases.

Answer: (A)

The concept being tested is that small changes in customer demand can become much larger as they move up the supply chain. This amplification is known as the bullwhip effect.

In practice, a tiny uptick in what customers buy at the retail level can trigger retailers to order more than the increase suggests, just to avoid stockouts. The wholesaler then sees those larger orders and places even bigger ones with manufacturers, who respond by ramping up production even more. Upstream suppliers likewise experience even bigger swings. The result is bigger swings in orders and inventory as you go from the consumer to distributors, manufacturers, and suppliers, which leads to inefficiencies like stockouts or excess inventory and higher costs.

This isn’t about demand simply being dampened downstream; it’s about amplification of demand signals. It’s also not correct to say it’s caused only by forecast errors—though forecasting contributes, multiple factors such as order batching, price promotions, long lead times, and information delays amplify signals. And lead times becoming shorter isn’t what defines the phenomenon; it’s the tendency for fluctuations to grow larger as they propagate upstream. To counter it, supply chains can share real-time demand information, reduce order batching, stabilize prices, and shorten lead times.