The classic Forrester three-echelon supply chain model is frequently presented by authors, researchers and consultants as an example of the dynamical problems inherent in a badly designed supply chain. In particular, the Forrester model is said to highlight clearly the 'Law of Industrial Dynamics'; that is, demand is amplified at each echelon of a supply chain. Despite such widespread acceptance as an example of supply chain 'problems' there is no evidence that the Forrester model has been used as a basis for studies on developing general principles whereby such 'problems' may be avoided. In order to achieve the foregoing objective, this paper presents the analytical steps required in obtaining an understanding of the internal workings of Forrester's supply chain. Following the derivation of a block diagram representation of an echelon
within the supply chain, system simplification is undertaken via the elimination of redundant information paths. Without this vital step, there is little doubt that the fundamental problem with this supply
chain (that orders placed on an echelon pipeline comprise 'real' and 'safety' orders) would have been missed. Instead, by highlighting this fact at an early stage in the research an appropriate range of solutions may be developed.
The paper describes the simplification procedures adopted.