Approximately Bounded Risk Regions,

Abstract

A Grass Root estimate consists of dividing a complete project into identifiable activities which taken together include all required tasks - a Work Breakdown Structure (WBS). The cost to complete each activity is separately estimated, usually based on a mixture of experience and analogy with previously completed similar tasks. These WBS element estimates are then added to become a total cost estimate. Usually manhours are estimated and dollars are found by applying the rate applicable to each skill code. Also various additional factors are also included, such as indirect allocations, G&A and fee. These factors add some computing complication but do not change the basic approach, so they will be ignored here. An uncertainty analysis covers the same ground. It uses the same WBS. However, the cost estimates of the individual WBS elements are expressed as probability distributions rather than point estimates. Then it adds the distributions to obtain a total probability function. This resulting function expresses the range of possible costs in terms of their probabilities of being achieved.

Document Details

Document Type
Technical Report
Publication Date
Jul 15, 1983
Accession Number
ADP002309

Entities

People

  • J. J. Wilder
  • R. L. Black

Organizations

  • Grumman

Tags

DTIC Thesaurus Topics

  • Acquisition
  • Cost Estimates
  • Costs
  • Mathematics
  • Probability
  • Probability Distributions
  • Random Variables
  • Uncertainty
  • Virginia
  • Workshops

Readers

  • Computational Modeling and Simulation
  • Mathematical Modeling and Probability Theory.
  • Surface Engineering/Surface Coating Technology.