Using Part Family Members in an Assembly
Part families are especially convenient to use in assemblies. From a single part file, you can assemble multiple instances and multiple occurrences of each instance in multiple assemblies.
If you have a Assembly license, instances from the same family can be exchanged with each other when you use the Replace command.
After an instance of a family has been assembled, it can be replaced automatically with any other instance in the same family, if the replacement instance has all of the necessary features for assembling (that is, no features used in the assembly process are suppressed).