Western Michigan University (WMU) maintains an online primer showing how to compose various types of formal business reports including memos and expense reports. These reports are used for internal communication within businesses, typically informing supervisors of operational trends or else as a way of facilitating communication between departments.
Business reports are technical in nature. They must explain functionally and in easily understood language how a process is proceeding or how a hierarchy functions, notes WMU.
Business reports must also evaluate going methods and, if needed, propose solutions or improvements to streamline best practices further. They demand a degree of personal initiative from their writers not present in other technical documents.