What will you do once you know that you are going to lose project/job/deal?

Good afternoon sir, If will nearly happen that I am lose a project or a deal, I do all my best to talk to the person whom will disregard my project. I will talk to him or her and asking what is the problem...of course there a reason why I am gonna lose that project, if there's any problem, I will do my best to solved it. It is very hard from my part....so I will encourage the person to continuation of my project. That's all sir,my answer very simple but it is not easy to convinced someone not satisfy on you. Thank you sir.