You do the financial analysis of a business plan (business idea) primarily for yourself, in order to prevent investment risks, and not because of potential creditors or co-investors.
The potential lender is primarily interested in whether you are creditworthy, or what you can offer as a loan guarantee, ie. whether you have a property unencumbered by a mortgage, which is at least twice the size of the requested loan and is attractive, that it can be liquidated quickly if you do not pay the loan installments. If this is ok, they analyze your credit rating that you submitted with the loan application according to their form. In addition, the creditworthiness will be checked through official institutions (more on the blog: INVESTMENT AND CREDIT CAPACITY OF INVESTORS),
The potential co-investor is primarily interested in who you are, which includes your previous references, and if they are ok, they check it as potential creditors through official institutions, and then analyze the correctness of the presented financial analysis, with emphasis on procurement and sales market analysis and SWOT analysis on the SWOT ANALYSIS blog).