The constituents of "value for money"
Matrices can be a useful means of showing the results of different combinations of things In this matrix I show how three different performance attributes can be seen as the results of different combinations of change in unit costs and effectiveness.
PS: DFID and ICAI documents talk about Value for Money (VfM) as being made up of three elements: Economy, Efficiency and Effectiveness. But if we take VfM literally, as being about a relationship between value and money, then two of these three elements don't belong. Economy is just about money and effectiveness is just about value. For more, perhaps too much, on ideas about VfM, see this list of documents at www.mande.co.uk