CHAPTER 4
Estimating Models
The most accurate and most reliable estimate for a project can be developed when all the elements of the work breakdown structure (WBS) have been identified with a reasonable degree of reliability and when the resource breakdown structure (RBS) has been defined with the desired degree of certainty. This estimate is referred to as the bottom-up estimate and it is derived from detailed information that is contained in the WBS and RBS at the time of the estimate. Unfortunately, the amount of detail required for such an estimate is not available until a major portion of the project has been designed and implemented. Notwithstanding, ...