The work breakdown structure allows us to approach the formidable task of finding all of the work that is necessary for completion of the project. This is done by taking the formidable project and dividing it into small projects that can be looked at one by one, allowing the project to be attacked one piece at a time. When the work breakdown structure is not used, it is very likely that many of the tasks will be missed. Since this is the place in the project where the work is defined, we find the work breakdown structure useful in determining much of the information we will require in our project plans.
To make work breakdown structures even easier, they are not restricted to only dealing with work. Many work breakdown structures start out as product breakdown structures. That is, the first few levels of the WBS are the breakdown of the products of the project from major products into smaller subproducts. For large projects this frequently makes the construction of the WBS much easier. If, for example, you were to consider the construction of the U.S. space shuttle, you would first see a product breakdown followed by a work breakdown.
Some of the major components of the space shuttle program were construction of the launch facility, construction of the space shuttle vehicle, construction of the solid rocket boosters, construction of the external fuel tank, modification