Sharing Demand Signals: A New Challenge to Improve Collaboration within Supply Chains
Karine Evrard-Samuel
University Pierre Mendès-France Grenoble II, karine.samuel@upmf-grenoble.fr

The purpose of this article is to provide an overview of collaborative demand planning. This article focuses on this practice particularly when information is shared in the downstream supply chain between a manufacturer and a retailer. We show how a manufacturing supply chain needs to be aligned with the retail supply chain in order to create value for the trading partners and for the end consumer. Through the analysis of three case studies we attempt to identify which practices allow efficient collaborative demand planning. Regarding the findings, different types of demand signals are identified through the planning process and allow us to highlight some breaking points that prevent the alignment and optimization of the retail chain. Research implications are the identification of four steps in the demand planning process that will help managers to better understand which actions should be taken to improve their collaboration practices. The originality of this article lies in the fact that it goes beyond historical demand figure analysis and focuses instead on information sharing about demand signals within supply chains as one of the keys to responding to retail demand with greater agility.

Introduction
One of the main challenges that firms have to face within the current environment is to increase customer satisfaction, service, and competitiveness at a worldwide level. The retail supply chain plays an important role in achieving this goal because it includes the consumer in the supply chain planning process. Consumer demand has dramatically changed since the beginning of this century. The consumer now has the opportunity to buy what he wants at the price he wants to pay. If the