From section 08 of the manual, regarding the Cost Accounting Worksheet:
R12.
Example 7: A Team purchases a 4 ft. by 4 ft. (~122 cm by 122 cm) sheet
of aluminum, but only uses a piece 10 in. by 10 in. (~24 cm by 25 cm) on
their ROBOT. The Team identifies a source that sells aluminum sheet in
1 by 1 ft. pieces. The Team may cost their part on the basis of a 1 by 1 ft.
piece, even though they cut the piece from a larger bulk purchase. They
do not have to account for the entire 4 by 4 ft. bulk purchase item.
My question:
If we use a large piece of stock to fabricate multiple parts, do we have to find a source that sells stock sized for each part and use this as the cost per part, or can we take the cost of the entire piece of stock and divide it between all of the parts that were fabricated from that stock?
For example, if we used the 4 ft by 4 ft sheet of aluminum from example 7 to make multiple 10 in by 10 in parts, do we need to price each part as though we purchased a 1 ft by 1 ft piece for each one, or do we take the total price of the 4 ft by 4 ft sheet and divide it into each part we made? (Assuming this results in a lower price per part.)
You can cost it at whatever combination of whole stock sizes is most advantageous, as long as you could have made all the parts out of that combination of stock sizes.
EDIT: that means you cost it at 1 entire 4’x4’ sheet to cover all the parts you made out of the sheet, for example. Or a 1’x2’ sheet + a 1’x1’ sheet if that would have worked.
What you CAN’T do is take the price of a 12’x12’ sheet and multiply by 1/144 because you only used 1’x1’. The rules are to prevent funny math like that. They also incidentally restrict the usage of items that can ONLY be bought in bulk at +$400 prices.
Trying something new this year…not using the template, but making our own similar spreadsheet. And not listing each part on the robot, but instead listing the items we bought to make those parts. For example, the half sheet of 1/2" plywood is only listed once, although it was used to make 7 different parts of the robot.
It’s now a Cost Accounting Worksheet, no longer a Bill of Materials. I think that means we only need to use it to account for the cost of building the robot.
We’re doing something similar. Things are grouped by what mechanism they went into, but things cut from stock that went into multiple parts are only reported once and commented. We’re also (for the first time) figuring out how much our robot would cost if we paid for the KoP and items costing less than $5 in a separate column.
This is probably the most irritating part of the CAW. We buy our aluminum and plastic in bulk & we have a lot of carry over from year to year. While I have a per piece price, the price is affected by the total pounds of the order. Since we have the head room on costs, we have started to put the bulk pricing on the CAW. Rather than trying to figure out a reasonable pricing for smaller quantities. IE 20 ft stick of 1x2x.125 rectangular tube. We have yet to have an inspector ask how we have 200-0 lb of Al on the robot. :]
No but it simpler for me to put the bulk cost of the raw stock down rather than to pair it down to the aluminum actually used and then chase down mythical prices.
