My thoughts
for what it's worth, you should not have to tailor your business plan after a quality standard.
As an example, I work for a major corporation who wants their business plan in a certain format. We will NOT change that for a quality standard, and I don't think the TS standard requires a format.
I believe that any auditor will ask the GM or CEO if you have a plan. They should not ask to see it as this is proprietary information.
So, IMHO, you should not have to worry about the format of the business plan, only that your company develops one and uses it to guide it's business operations.
As an example, our company has an annual plan and a long range plan. The annual is for the next calender year and the long range is a rolling 3 year plan.
But, as I said, as far as I know, the auditor should not ask to see the plan, but only ask if you have one.