In general, a recommendation without identifying its costs and benefits or a recommendation to seek more information is unacceptable. It shows sloppy thinking. Student teams will be randomly assigned one case to present to the entire class and will be randomly assigned one case presentation to critique. If the case lends itself, analysis using a spreadsheet can be very effective. Spend time thinking about the best way to set up your spreadsheet before you begin.
Cases often involve examining a question under different assumptions.
It will usually make sense to set up a separate section in the spreadsheet for numbers that might be changed later as part of a sensitivity analysis. But be careful. The quantitative aspects of a case can lead you to confuse mathematical precision with correctness. Keep in mind that a numerical answer is less important than thinking about the question in the right way, and that an answer is only as good as the assumptions underlying it. Cases typically provide incomplete or vague information about a situation, and you may find that you have to make an assumption to proceed.