identified over 30 years ago in the

identified over 30 years ago in the USA by Jay Forrester and in the UK by John Burbidge. Regrettably, as Towill[6] has shown, many of these lessons are rediscovered the hard way and at great expense to industry. There are very few examples of a single-echelon chain where raw material is sold directly to the end customer. Invariably, the development of raw material through to finished goods will take many changes of form and