By definition, acumen is the ability to make good judgments and quick decisions within a discipline or field of endeavor. To make good judgments and quick decisions in business, an individual must have business acumen.
I was promoted to my first management job when I was 22. I had been at the company for a little less than a year and was asked to step into the role of assistant manager. It was for a moderate sized store that belonged to a retail chain. I lasted less than 4 months in that role. Now, let’s ignore for just a moment the fact that I never wanted a career in retail in the first place, and only took the job because the market looked grim at the time. Regardless of this is the fact that I was not prepared or developed to be put in that leading role in the first place.