That is a tough question.
To food safety professionals the idea of developing a schedule based revenue is not realistic. We develop plans, programs and procedures based on risk, regulatory requirements, and customer requests.
since your question seems to me to be more micro orientate - one thing to remember is that pathogens are notoriously elusive to find in products. Thus you may sleep better testing one sandwich per 2000 produced. However, unless there is a major issue your likely hood of finding anything are somewhat small
I don't know what you make so these are some general ideas / suggestions.
Raw materials \ ingredients - I would create a risk analysis for each raw material / supplier combination. the analysis could be for both quality and food safety attributes. Then decide which ingredients have critical aspects that need to be tested. It may be that you don't have to do any testing on raw materials. or it could be as simple as a color, odor, appearance, taste (organoleptic) test done in house. There may be some that your chose to send out for micro or other testing. While I have always said that relying on your suppliers for your incoming ingredient quality is bad idea, it may be what you have to do until you grow and have the resources.
Finished product. - the same really applies to finished product as it does to raw materials. What is critical to you and what is the risk? However, you may have customer requirements that also figure determining what testing might need to be done.
environmental - as a RTE plant this one is pretty important. there are a lot of resources out there to guide you in how to set this up. My theory for environmental swabbing it to make a list of every single equipment and area that could be tested. Then do your risk assement to determine the organisms and frequency of testing needed. For food contact surfaces (zone 1) ATP could be your friend. its pretty cheap and easy and will either give you confidence in your sanitation program or indicate issues quickly.. You may feel better about a lower frequency of swabbing these areas. Chose your organisms wisely in some cases it may be prudeint to use a indicator test such as coliform or Enterobacter instead of a pathogen test.
Whatever you do, remember where you are to day and set goals to improve over time. ie improved incoming ingredient monitoring, increased swabbing, inhouse testing, etc
this is all pretty general. I hope it helps. If you tell everyone what you are producing / process it may help others chime in with suggestions and areas of concern.