Your cases will be written in a business format. Clarity of thought on paper is important, as is the research that you must do to form your arguments. Generally speaking, the good papers are those which show much more than the 3 required references, and are usually over 10 pages in length, including cover page and reference page.
The format is required is as follows:
Executive Summary – separate page
Analysis and arguments (SWOT, Porter 5-forces, Staying Power video)
Summary and conclusions – separate page
References – separate page – minimum 3 from reliable sources