First, representatives must know their customers and the general design intent of each project. Although these processes have many similarities, each delivery method has its own project phase requirements, which includes requirements for substitutions. The type of customer, the design intent, and the project delivery method set the parameters for the type of specification that will be used for project documentation and management. Manufacturers must also understand how these specifications are developed so that they can present the right product information at the right time and receive fair evaluation. Typically, the subcontractor initiates the substitution, but manufacturers or contractors also can be the driving force.
Substitutions usually originate during the bidding or negotiating phases.
However, when it comes to design-build, who approves substitutions and what procedure is being used at what phase of the job becomes a lot more complex. It is extremely important for manufacturers representatives to understand procedures for the various stages of bidding before, during, and after bid submittal. The term or equal has been the source of much debate. Product specifications for local, state, and federal agencies normally require consideration of all products that meet specified requirements. Some specifiers use language such as or equal after listing several products or manufacturers.