Develop a preliminary WBS for a small one-story commercial building to be constructed on the site of an existing small-frame structure. It is 30 by 60 feet in plan (see illustration). The exterior and interior walls are of concrete block. The roof is constructed of bar joists covered with a steel roof deck, rigid insulation, and built-up roofing. The ceiling is suspended acoustical tile. The floor is a concrete slab on grade with an asphalt tile finish. Interior finish on all walls is paint.

a. Show the first level of this structure for the total project (WBS is developed from top to the bottom).

b. Select one work package (or building system) of the first level and develop the second-level structure for this work package.