While these causes expect rational decisions of all supply chain members (operational causes), irrationality or opportunistic behaviour (behavioural causes) is another source of the bullwhip effect (Croson andDonohue 2006). As a result of those causes, demand and stock variation propagates upstream with amplification occurring at each echelon of the supply chain. Carlsson and Fuller (2000) summarized the effects of the bullwhip effect following Lee et al. (1997a and 1997b)