case studies

[Trwsh]

hello
i want to ask about case study exams and the plan  or format that would be ideal.
when we introduce our case studies, say if i talked about two businesses how would i structure it under the topics i will be talking about? do we talk about both businesses under one heading ? i find it hard to minimise my paragraphs as i always end up talking about both businesses under one heading then having no time to write for other headings