The Ripple Effect in a Supply Chain: A Sudden Demand Increase and with a Sinusoidal Component

This paper studies the backward travel of a disturbance ripple up the chain to the upstream units subsequent to a disturbance at the downstream end, on which topic there have been a lesser number of studies. The nature of the problem leads quite naturally to the use of dynamic analysis; and hence we examine the ripple effect in the chain through the study of the dynamic behavior of a three-stage chain. We derive the dynamic behavior of each of the stages under the most common and frequently encountered dynamic replenishment control schemes under such conditions. Concomitantly we derive sufficient conditions on the control parameter settings for the arrest and prevention of the back propagation of the disturbance upstream. A notable feature of these dynamic controls is that they can be made pro-active as is shown in the paper to effectively decouple upstream stages from the downstream ones. The paper delineates the roles of each of the control parameters and presents the planner with effective ways and means to arrest and prevent the backward travel of the ripple to upstream units. The paper also makes a case for effective information sharing between the stages in order to achieve this objective.