Extended modules > Creo Elements/Direct Sheet Metal > Creo Elements/Direct Sheet Metal customization > Cost estimates
  
Cost estimates
The cost estimates derived by Creo Elements/Direct Sheet Metal users are governed by a number of parameters derived from the 3D data model or held in the cost model itself.
This chapter discusses the following topics:
• The Cost Model File
• Creating and Applying a Customized Cost Model
The Cost Model File
The cost model file derives the following information from the 3D model:
partname
Creo Elements/Direct Modeling name of the sheet metal part
material
Material ID
thickness
Material thickness
bends
Number of bends
diff-bends
Number of different bends
hems
Number of hems
diff-hems
Number of different hems
flat-width
Width of box enclosing flat
flat-height
Height of box enclosing flat
body-width
Width of box enclosing sheet metal body
body-height
Height of box enclosing sheet metal body
body-depth
Depth of box enclosing sheet metal body
punches
Number of punch features
diff-punches
Number of different punch features
stamps
Number of stamp features
diff-stamps
Number of different stamp features
nibble-len
Total length of non-feature elements
contour-punches
Number of non-straight non-feature elements
The following information is held or calculated in the cost model itself:
x y
Size of the raw sheet supplied by the mill
cost
Unit cost of a single raw sheet
punch-qty-x
Number of flats that fit horizontally on a single raw sheet
punch-qty-y
Number of flats that fit vertically on a single raw sheet
punch-qty
Number of flats that can be produced from a single raw sheet
punch-qty-rotated
Number of flats rotated by 90 degrees that can be produced from a single raw sheet
punch-runtime
Punching machine time per part
punch-setuptime
Punching machine setup time
punch-rate
Cost of punching machine per time unit
fold-runtime
Folding machine time per part
fold-setuptime
Folding machine setup time
fold-rate
Cost of folding machine per time unit
mat-costs
Material costs depending on lotsize
punch-costs
Punch costs depending on lotsize
fold-costs
Fold costs depending on lotsize
The cost model uses this information to calculate fabrication costs. For instance, the costmodel.lsp file includes the following section specifying the dimensions of sheet metal supplied by a given steel or aluminum rolling mill:
((string= material "AA 5052" ) (setq x 1000) (setq y 1250) (setq cost 12.5))
((string= material "UST 1203") (setq x 750) (setq y 1000) (setq cost 17.5))
((setq x 750) (setq y 1000) (setq cost 17.5)))
;; default cost/size
This section implies the following:
• By default, the AA 5052 aluminium sheets measure 1000 mm by 1250 mm. The unit cost per sheet is 12.5 arbitrary currency units.
• By default, the UST 1203 steel sheets measure 750 mm by 1000 mm. The unit cost per sheet is 17.5 arbitrary currency units.
* 
Creo Elements/Direct Sheet Metal does not process any currency parameter. To account for any local currencies, you simply change the cost figures.
Sheet Size
The sheet dimensions specified in the cost model file govern the following parameters:
• The maximum size of any sheet metal part (flat) which can be produced from this sheet;
• The yield (quantity) of sheet metal parts per sheet. The formula used by Creo Elements/Direct Sheet Metal to compute the yield is also included in the costmodel.lsp file. Creo Elements/Direct Sheet Metal simply checks the horizontal and vertical dimensions of the flat against the size of the "raw" sheet stock.
Fabrication Process Times and Rates
The costmodel.lsp file defines the following process times and rates for the punch, stamp, bend, hem, and offset processes:
• operation runtime
• setup time
• rate per machine hour
• rate per second
Lot Size
The following default lot sizes are specified in the costmodel.lsp file:
• 1
• 5
• 10
• 50
• 100
• 500
• 1000
The costs are calculated for each of these lot sizes.
Creating and Applying a Customized Cost Model
By creating a working copy of the costmodel.lsp file supplied with Creo Elements/Direct Sheet Metal and editing this copy, you can quickly and easily create your own (custom) cost model file.
Proceed as follows:
1. Copy the costmodel.lsp file to a filename such as my_costmodel.lsp.
2. Use any text editor (such as vi) to open the my_costmodel.lsp file.
3. Add any custom materials (see Materials) to the new cost model file. Be sure to specify the as-supplied size and cost of any additional material.
4. Change any other parameters (such as runtimes, setup times, rates, etc) as appropriate.
5. Save the cost model file.
6. Unless you are using default paths, be sure to specify the full pathname of your new cost model file in sha_customize. See Implementing Customized TDB Files for details.
You can repeat this procedure to create multiple cost files for different divisions of your organization.
* 
Please note that the cost model always applies to the latest flat.