Business leaders rely on accounting data such as profit and calculated costs as a guide to whether they are making money. Should they?

Accounting was designed to report financial performance not model cash flow. Accruals can disconnect cash flow from the timing and extent to which it occurs. Statements of cash flow do not provide insight into what was bought and how efficiently it was used. Costs and profits are not absolute, they change based on the model you use to calculate them. To manage cash, you must manage what you buy and how effectively you use it. The largest expenditure...