When you visit the automobile dealer to purchase a car, you buy the car based upon your personal needs, your research, value performance, etc. You negotiate the price, choose the options, and make your decision.
A municipal OEM manufacturer is much the same as the automobile dealer. They consultant along with his customer, the owner, defines the requirements. They contact your representative and spell out the features and performance they want. Budget prices and cut sheets are sent, and sample specifications are issued in this beginning portion of design.
At this early stage, very few engineering disciplines are involved. This is the key piece to understanding the core cost escalation issue at this stage. Rep wins preferred bid advantage, or the A-spot, and is ultimately sole‐source for the project.