The number one problem with cash flow is seen in a breakeven business that trades one dollar for four quarters. The first time you get less than four quarters back on the dollar you spent to earn a dollar of sales, the real problems begin. Too that for too long, and you are bringing in less cash and thus profit losses than you are earning in sales. Breaking even is not a sustainable business model.
Overview
Most people think that the number one problem with business cash flow is collecting the money owed to you; this is the number two issue. The number one issue with the velocity of your cash collection is cash quality.
If all your business does is bring in dollars to pay your employees, suppliers, and everyone else but not you, then you have a problem. When you only leave yourself pennies on every dollar you pay out to everyone else, you will quickly owe more than you collect. When this happens, you now have a real cash velocity problem.