Work breakdown structure (abbreviated as WBS) is the core step in project management. It is put forward in 1993 aiming to make the big project more manageable in details. To be more specific, WBS is a structural schematic diagram that decomposes tasks layer by layer according to an internal structure or an implementation process. It breaks down the project into several relatively independent, single content, and easy accounting work units. A great work breakdown structure will lead to better team productivity and comprehensive project management.