Explain what is the relation between the system aim and the variables and why did you choose that variable as a variable?

I have a paper which is done by your organization. But it doesnt cover all of my needs. I will send it to you to continue with that document instead of making a new one. What ı want is there must be approximately 20 variables. paper covers 3 of them right now ı want you to add some more and explain what is the relation between the system aim and the variables you choose. And also ı want you to explain explicitly why did you choose that variable as a variable? everyting clear? ı will provide 2 pdf document that show how it should be. This is very important for me to reach that 20 variables! ı will send you a document that writes what my lecturer wants in the first delive of the term paper.