work breakdown structure
While work to be accomplished by subcontractor may be specifically identified, there are often different kinds of work to be accomplished by the general or subcontractors. These types of work often have different types of payment schedules that require the inclusion of multiple schedule activities. For example, including activities that have a high-proportion of equipment (and thus front-loaded activity cost) should be separated from activities that have a consistent level of material and labor use (whose value is earned on a cost per day basis).