Transcript Pre-Feasibility Study Cost Estimation Resources

Pre-Feasibility Study Cost
Estimation Resources
©2002 Dr. Bradley C. Paul
Pre-Feasibility Study
Order of Magnitude Estimates Determined
which things would be considered
 Pre-Feasibility Study Determines whether
there is enough promise to justify the effort
required to move forward
 Feasibility Study (generally 10-30% +/-)
 Next Moves to Project Approval (5-10%)
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Pre-Feasibility Study
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Pre-Feasibility Study
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Requires that you have a concept for what
going to build
Break project down into areas and tasks
 Outby
Haulage
 Ventilation
 Mine Workings
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Costs of Components Done Separately
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Need to include everything
Methods of Getting PreFeasibility Cost Data
Clear List of What is Included to make sure
all components are included
 Begin to Find Manuals Available
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EPRI Coal Mine Cost Model (about 1981)
Bureau of Mines Cost Estimating System
(1984)
SERPA Cost Program (current)
Western Mine Cost Service
Typical Cost Manual Approaches
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Factored Cost Estimates
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Use Curves that are a function of some over-all
characteristic
 Example
US Bureau of Mines Cost Estimating
System
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Itemized Cost Estimates
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Specify cubic yards of concrete
Apply a cost per cubic yard
Used by EPRI and Serpa
Strengths and Weaknesses
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Factored Cost Estimation Approach
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Requires a lesser degree of engineering detail
be worked out to run
 all
costs linked to a specific generally known
parameter
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Lets get closer to answer with less work
Itemized Cost Estimates
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Structure is same as Feasibility Estimate
 allows
more transparent transition to Feasibility
study estimates
General Comments on Major Cost
Estimation Resources
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EPRI - Coal Mine Cost Model
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Most cost model resources are for hard rock
and industrial minerals - this one is coal
Model covers coal mining costs but is weak in
ancillary facilities and some capital costs
 Example
- No capital cost capability for shaft or
slope
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Model linked to a computer program that has
not been updated
 1981
software in the 21rst century looses a lot
More EPRI Comments
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1980 and 1981 cost base
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needs significant inflation indexing
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will see later that knowing how much to index with what is
important
doesn’t show which indices to use on what
Productivity Sensitive
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crews and advances done with simulations current in
1980
coal mine productivity has increased about 250%
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are some productivity indices from BLS but not a common
updating procedure
SERPA
A Hardrock Package
 A comprehensive mine cost package that
has been maintained to fairly current status
with costs
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is private so seeing exactly what is in the package is not
really possible
fairly current still means the driving routines run in
DOS
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cryptic key sequences and IO problems
suspect that costs are updated but engineering assumptions in
code may not be
SERPA
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Has a lot of defaults built in
Has relatively simple categories of mine needs
May almost be able to run at at the fairly precise
order of magnitude estimate stage
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most manuals really can’t help you till get to
prefeasibility
Ability to add details and replace defaults gives system
power that extends up into pre-feasibility
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weaknesses in showing details of output probably make use in
feasibility stage really questionable
Western Mine Cost Service
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Collection of cost models and typical item prices
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comes as articles over time
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makes comprehensive approach at any one time questionable
may have to inflation index different parts of mine cost
separately
very vulnerable to holes in needed costing
Hardrock manual that has some coal mining
equipment items in it
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can use on coal but comprehensive approach problem
Western Mine Cost Service
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Place where manual shines
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identify a critical cost area and you want to get down to
itemizing equipment or features and need costs
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great alternative to fishing for vendors that will give you prices
before your really shopping for equipment
event is likely to occur as Pre-feasibility study moves
into true feasibility study
Manual caters all the way from Order of Magnitude to
Feasibility but is comprehensive nowhere
US Bureau of Mines Cost
Estimating System
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Prob the most comprehensive high precision
pre-feasibility manual ever written
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No holes - covers everything
Too much detail and work to function in Order
of Magnitude Estimation
Factored cost estimate approach is not
compatible with itemized detail needed in
critical areas of Feasibility Study
Manual is clearly hardrock
 not
good for quarry’s either
Status of BM CES
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Mid 90s Congress killed Bureau of Mines
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manual has been without caretaker
lots spin off people went to Western Mine Cost
and Serpa came from BofM
Had beautiful spreadsheet program that ran
manuals rapidly
 was
designed for Lotus 123
 not updated to latest spreadsheets and some macros
don’t work
Status of BM CES cont
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Had automatic cost indexing but that’s not
been maintained
 fortunately
same index structure was picked up by
Western Mine Cost which has been maintained
 getting recent indexing into spreadsheet model is an
on your own
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can do it manually as you will see