Consulting services vary according to the wishes of the client, ranging from brief surveys of a day or two to in-depth analysis and design.
Proposals are prepared and quoted as fixed price per diem, as specified by the client.
Income is derived solely from consulting services performed for clients. My experience spans more than 40 years, all in packaging and handling, with the last 15 years in private consulting to more than 100 clients of all types, including 22 of the Fortune 500.