抄録
The mythical man-month law claims, "Adding manpower to a late software project makes it later" and is understood correctly because software product is not divided into smaller units such that human can work on those smaller units immediately and in parallel. This is stated in short that the man-month quantity differs from the calendar month quantity. ln addition, two tasks of the same size require different workloads if the sizes of the systems to be developed are different according to the COCOMO II model. The work breakdown structure (WBS) assumes independence among WBS items in estimating the workload in man-month unit, allocating project budget over the work items, and developing the schedule given in the calendar month. In this paper, we first show that, especially for IT projects, the mythical man-month problem is inherited in such practices that utilize the independence assumption on WBS items. Secondly, according to the WBS based current practice on the cost budgeting, we show that a project will be late in the calendar time if the resource is estimated and allocated to each work item such that the work items are assumed to be independent from the other items. A new method of resource allocation (new budgeting) that is consistent wilh the person-month concept and the COCOMO II model is proposed so that project delay is avoided.
