Optimise-GB gives a presentation on Activity Based Costing (ABC) and Zero Based Costing (ZBB). These methods illustrates how ABC and ZBB can be used to calculate unit cots taking into account variable, semi-fixed and fixed costs by splitting the costs by usage, time, space and volume from scratch. This ensures that assumptions are not taken into account and factual costs are applied so that true margins may be derived. Thank you Simon Misiewicz