updating of demand forecasts: resulting in changes to safety stock and stock in the pipeline;
order batching: while retail customers may buy mostly on Saturdays, MPC systems may batch orders according to different timing rules;
price fluctuations: promotions most often result in lumping of demand into peaks and troughs, when the ongoing pattern is stable;
rationing and shortage gaming: when the latest games console is in short supply, retailers are rationed by manufacturers. Customers place multiple orders on different retailers, causing apparent demand amplification.