Why do you need to know these percentages? As your sales increases or decreases, your material cost, labor cost, and variable expenses will track accordingly. They will track very close to the same % as your current business. As an example, let's say your current sales is averaging 贄ꯠ per month and your material cost is averaging ฤꯠ per month. That's 20% of your sales (ฤꯠ ÷ 贄ꯠ = 20%). So, what would your material cost be if your sales were averaging 赨ꯠ per month? It would still be 20% but it would be 20% of 赨ꯠ or ุꯠ. So with these percentages, you can project your material, labor and variable expenses. See how it works?
It could be, for example, the risk of a change in the economic environment _ what are your contingency plans for that in terms of dealing with such a situation? There may be many other risks as well specific to your particular sphere of operation, but that ability to plan ahead for all scenarios makes for a robust business plan. When I have received business plans, the very best responses come from people who have looked at the risks and have an answer for every question. What you never want is to throw a scenario at your plan and have to answer "I don't know what I would do in that situation". You want to plan for every possible contingency, and certainly all the major risks to the ongoing success of your business.