estimating schedule activity costs involves developing an （） of the cost of the resources needed to complete each schedule activity. Cost estimating includes identifying and considering various costing alternatives.for example，in mostapplication areas，additional work during a design phase is widely held to have the potential for reducing the cost of the execution phase and product oprations.the cost estimating process considers whether the expected savings can offset the cost of the additional design work.cost estmates are generally expressed in units of （） to facilitate comparisons both within and across projects.the （） describes important information about prject requirement that is considered duing cost estimating.