The rational "No". How to refuse a customer in win-win way

In IT, there is often a situation where development and business are separated. This model inevitably generates disputes about the time, money, and resources between key stakeholders, subject matter experts, engineers, project managers, and budget holders.

Being structurally on the development side, the analyst is forced to be torn between the team's interests and the customer's demands. But what if those demands seem incompetent, silly, or even harmful to the project?

I will tell you how to keep calm, figure the problem out, and get out of the situation in a win-win format.