This model example uses an Allocator element to select from multiple supply sources to provide for a demand that is less than the sum of supplies.
GoldSim provides a built-in element for allocating demands for a scarce resource called an Allocator. An example of a typical allocator application is described here. A less typical but important application is when you need to allocate from multiple supplies that exceed demand. If the demand is less than the sum of all supplies, then this type of problem is also an allocation problem but is used in the opposite way from the typical demand allocator application.