1. A computer-implemented method of planning demand for a configurable product having at least one product dependent characteristic and one product independent characteristic in a managed supply chain, comprising: providing a data storage system to store data with respect to a plurality of product independent characteristics and product dependent characteristics; receiving, by a processor, a selection of at least one product to be represented; receiving, by the processor, a selection of a particular characteristic to be represented; receiving, by the processor, a planning parameter with respect to the selection of a particular characteristic or product; loading, by the processor, data from the data storage system into a buffer; performing, by the processor, a calculation on the data with respect to the product dependent characteristics and the product independent characteristics; modelling, by the processor, a hierarchy of the represented data, wherein the hierarchy is defined in accordance with the planning parameter; and using the hierarchy to administer the buffered data, the administration of the buffered data comprising performing a propagating recalculation of a change in the data through the data storage system, wherein the recalculation differs from that defined by the planning parameter and includes calculating an incidence of each product dependent characteristic and each product independent characteristic in accordance with the selected product.