A fundamental key to getting the work/job done is insuring that you carry your colleagues/customers support and if your work in the public sectors then the general public too.
What is winning the argument?
If you are responsible for implementing any sort of change with in an organisation than you are going to have to convince different parties of your intentions and that the project is going to benefit them so that you can gain there support and help in implementing the project.
It is necessary with all projects to go through a consultative process and allow the people that will be effected by the change to contribute to the process. More than lightly you will face some resistance to your ideas. Your job is to demonstrate how your ideas will be effective and calm the user fears. If you are confident about project one can prepare for this by listing potential problems/fears users may have. By setting this out on paper you will be saving your self time in the future and will prepare the path for a smother transaction.
When I talk about winning the argument. I am talking about rational working through of concerns and demonstrating the effects of the concerns people may have. Some people may say that different opinions mean that both parties are right. While this may be the case with some moral issues. Implement projects has nothing to do that with that. If the goals are clearly defined. For example: The goal of this project is to implement a new security systems for five thousand employees in unobtrusive way. One would have to make decisions that insured these goals are met. While there may appear to be much scope in the process when it is refined down it is quite distinct and clear.
The end result of this, is that time is saved, you win the argument and the job gets done.