Start-up costs are those incurred when preparing to produce a line item. Different industries envision different costs. In laser cutting and sheet metal, it's mainly about loading and write-offs of sheets.
Write-offs
By write-offs, we mean that a fresh, untouched sheet has a disproportionately higher value than a sheet from which a part has already been cut.
To recuperate that high initial cost, DF offers the following option: Say a new sheet costs 10 euro per kilo, and it weighs 10 kilo. Thus the cost of the sheet is 100 euros.
Say you have calculated that just cutting that sheet, for however small a part, lowers its value by 10%. A part with a material value of 1 euro was cut out, but the remaining value is not 99 euros, but 90 euros. To compensate for this, you can set up the following field:
Once that's done, you can lower the price per kilo on sheet size level from 10 to 9: Should exactly 1 sheet be needed to produce the line item, you recuperate the whole value: 10*9+100*0.1=100. If less than a whole sheet is needed, e.g. half of it, you get 5*9+100*0.1=55. If one and a half sheets are needed, you get 10*9+100*0.1+5*9+100*0.1=155.
How we calculate: Initially, we compare the total surface area of the bounding rectangles of the parts in the line item with the surface area of the selected sheet. That tells us how many sheets are maximally needed to produce the line item. We multiply that by the per sheet start up cost and add the result to the cost of the line item.
Sheet loading time cost
The per sheet loading cost functions similarly and is calculated with these parameters:
and
Since the sheet in our example weighs only 10 kilos, only one operator is needed for 6 minutes. At an hourly rate of 10 euros per hour, that's 1 euro. Using the same initial calculation of how many sheets are needed to complete the line item, the result is multiplied by the sheet loading time cost (1 euro) and added to the cost of the line item.
After the order has been placed, you can combine all parts (so across line items) for one material and one thickness in nests. The initially calculated number of needed sheets will probably drop, so the cost of the line items in the nest will drop, and thus the cost per part.
The per sheet loading cost is calculated with these parameter
You can now send a new offer with a lower price to your customer.