Calculate the break-even number of customers per year for each concept at the operating profit, after-tax operating cash flow and NPV levels (in the above models, the cash flows per year areconstant, thus, customers needed to break-even at the NPV level is a meaningful question). Calculate the break-even number of customers per year for each concept at the operating profit, after-tax operating cash flow and NPV levels (in the above models, the cash flows per year areconstant, thus, customers needed to break-even at the NPV level is a meaningful question)