Stick with Plan A! Do Not Have a Plan B! If you have a Plan B, then you aren't fully committed to plan A. Motivational Video is below.
If you are committed to Plan A, then there isn't really a reason to have a Plan B. Your commitment, work ethic and sweat equity, undying devotion, long hours are all a part of Plan A. There will be obstacles and problems that come up but you can't give up.
A person may have a Plan B thinking that if plan A doesn't work out, they will fall upon Plan B.