risk analysis. Figure 8 has been developed from a collection of statistical values
over a long period of time and does provide some quick guidance to judging
accuracy of the estimates and then setting a contingency value. Detailed software
packages are available that can provide reasonable estimates, subject to the quality
of the inputs.
Figure 8 shows two sets of curves. The first is a positive to negative range of
accuracy against the type of estimate. This type of estimate scale is based on Fig. 7
Table 16 Semi-definitive cost estimate summary
Plant
Description
Date
A/C
Estimated cost, MM $
No
Item
M/h
Labor
Subcont
Material
Total
Excavation
Xxxxxxxxx
Concrete
Xxxxxxxxx
Structural steel
Xxxxxxxxxx
Buildings
Xxxxxxxxxx
Machinery/equip
17.876
Piping
Xxxxxxxxx
Electrical
Xxxxxxxxx
Instruments
Xxxxxxxxx
Painting/scaffold
Insulation
Direct field cost
Xxxxxxxx
Xxxxxxxx
Xxxxxxxxx
Xxxxxxxx
Temp const facil
Constr expense
Craft benefits and
burdens
Equip rental
Factor
Small tools
Field O/heads
Indirect field costs
Xxxxxxx
Total field costs
Xxxxxxxx
Engineering salaries
Purchasing sal
Gen office sal
Office expense
Factor
Payroll burdens
Overhead costs
Total office costs
Xxxxxxxx
Total field and office
costs
Xxxxxxxx
Fee (contractor)
Xxxxxxx
Escal/contingency
Xxxxxxx
Total costs
Xxxxxxxx
726
D.S.J. Jones and P.R. Pujado ´