There is no one metric. The business owner needs a dashboard of metrics to manage every day. But if I’m assessing the viability and vitality of my business at any given time, I’m looking at profit. Aggregate and unit profit tell the story. The business may be in debt, there may be cash flow issues, labor shortfall, vendor problems, pricing problems, collection delays and a variety of other things. Those costs need to be tracked and resolved but the one thing the business needs is to track its ability to create ongoing profits from sales.