I have an exam in marketing.The exam will be about analysis case studies.

I have an exam in marketing.The exam will be about analysis case studies. The professor will give us a case study and we have to analyze it ( identifying the problem ,finding alternatives,evaluating the alternatives, and writing recommendations) I don't know how I should start studying and preparing. Does anyone can guide me to the correct way to study or give me an excellent source that explains how to analyze a case study step by step? 

Thank you,