MRP is shorthand for materials requirements planning. Big Business offers simple planning functions so you can see how your orders may need you to build products, buy components and products, and plan for the arrival of items on purchase orders.
Show Allocated brings up a list of orders, including built items, that need the item you are viewing. In our example, Bike and Bike2 both need BikeWheels, which are a subassembly that needs BikeSpokes. Big Business tells you how many and when.