In the rush to outsource manufacturing to China, many companies are unaware of hidden costs, notes Boston Consulting Group.

Moving manufacturing to China means the supply chain is longer, therefore increasing the time it takes to get products into stores. Furthermore, the increased volume of goods moving through U.S. West Coast ports "is creating bottlenecks that are making supplies to retailers uneven," says the consultancy.

Part of the solution includes moving goods by airfreight, especially on "products with the highest margins and volatility."

In addition, the consultancy says shippers would be wise to pay a premium to get preferred treatment on shipments. This includes getting goods loaded last so that they're the first ones unloaded. Another tip includes choosing warehouses in less-crowded ports such as Savannah, Georgia and others.