Our simple 3 legged stool model from part 1 will deliver high performance at low cost and risk – i.e.: high productivity. It is important however to keep the legs intact! Doing so requires a bit of investment. In thermodynamic terms we need to put some energy into the system to keep the entropy from growing. That energy is investment in maintenance and the payoff comes in the form of steady, predictable revenues with a high margin for profit. Those words should be music to accountants’ ears.