I need help with the following assignment: Write a message to persuade your boss to invest capital resources to develop the product or service for sale. Include secondary research to support your argument and explain what you will do in case the selected product or service does not initially sell as much as expected. Cite and reference sources using APA formatting.

How you go about completing this assignment depends on the specific context and industry. It seems as though you are being asked to think of an example that is directly relevant to your own work experience.  As you have not specified where you work or in what industry, this answer will address the rhetorical issues of the assignment. 
You should note that this sort of assignment is most likely to be completed successfully if your chosen project is fairly modest. For example, if you work for a restaurant, rather than suggesting opening an entire new chain, you might investigate adding one dish to a menu or offering delivery in a very limited area during lunchtime.
You should use a standard report format for this project and include the following information:

Executive summary: This is a single paragraph which summarizes the main points of the entire report. It should specify the product you would wish to develop, what sorts of resources would be required, the time frame to bring it to market, and the benefit to the corporation (e.g. increased market share, broadening consumer base, establishing presence in some new market or area, enhancing company's reputation.) It should consist of fewer than one hundred words.

Description of product or service: This should be clearly written and describe the specific product or service you intend to develop in some detail.

Market Analysis: Here you should cover two things, the size of the potential market for the product or service and your competition.

Resources Required: This should cover human resources, physical resources, and amount of capital required. You might also include time to market here and what sort of impact it would have on the rest of the business (would you need to hire new people? temporarily reassign them?).

Exit Strategy: If your product or service is not profitable, you should have a clear exit strategy to minimize losses. 

Financial Projections: This should ideally consist of a short paragraph detail your assumptions and spreadsheets or other graphic information showing your estimates.