Defining valid cost elements for an OBS

IPP&E allows you to estimate the labor, material, and other costs for the work packages in a WBS work package. The different costs are estimated as separate cost elements for each functional work package. These cost elements are created for two broad groupings of cost categories. The first is the effort-based cost categories, which account for labor and other resources, and are estimated based on time. The second is the currency-based cost categories, which are estimated using currency values.

(The source page includes a diagram showing examples of cost categories and cost elements created in these categories — not reproduced here as it is an image.)