"There are no secrets to success. It is the result of preparation, hard work, and learning from failure."
Great men are great because of their consistency, Albert Eintein failed 99 times, but got it right on his 100th try, he later said that he discovered 99 ways to fail the project.
He learned from his mistakes, and surely never repeated any of those mistakes. Unplanned factors ranging from the economy, to finance, to customer based challenges hits businesses regularly, but learning from those step-backs will enlighten you on what and what will work for your kind of business.
Every new implementation should be properly thought out, fully considering the pros and cons.
Lastly, don't be scared of failing, as it is only a means of enligtenment.