Sorry, 2 to 5 years

Interesting subject.
I have completed diploma on marketing planning from Cergy, France.
First you have to select the item or items for business plan or marketing plan or strategic plan.
Usually a business plan / marketing plan comprises for 2 to 5 years and based on that strategic plan stands for 5 to 7 or more.
Budget is the key component of a business plan ( 4 P of marketing: product, price, place/market, persons) in which P & L is the life blood of the business plan. Its a vast subject.

Are you an animal lover? Yes? Then this latest business fad is yours to exploit! According to surveys, the pet sitting business is one of the fastest growing home based businesses today. Some career experts would say, going to be a pet sitter is also a wise career move.