Prev: proof of rearrangement inequality for >2 sequences?
Next: Applications of surface integrals
From: Gerry Myerson on 23 May 2010 19:28
In article
<fd6a30fe-e87c-4f0f-9655-f78845ab5c92(a)m21g2000vbr.googlegroups.com>,
Green <GreenRite(a)yahoo.com> wrote:

> At my work, we cut strips of metal from 41 inch wide coil. The metal
> strips vary in both length and width. Generally the length is in 2-
> foot increments, ranging from 10 feet to 20 feet. The width varies
> greatly. In one pass, a semi-automated metal shear first cuts the
> coil metal to width (the width cut is set manually) then to length
> (the length cut is programmed in).
>
> When the shear operator gets a batch of orders, he surveys the widths
> and lengths then makes a 'best-guess' at how to cut the metal strips
> -- first to minimize metal consumption and second to minimize setup
> time for the width cut.
>
> If necessary, the cut strips can be moved to another shear to further
> cut to length. For instance, if two strips are needed at 15 inches
> wide, one 12 feet long and another 14 feet long, we cut two strips at
> 14 feet long. Then one of them is moved to another shear to cut from
> 14 feet to 12 feet.
>
> If it can't be used immediately for another order in the batch, the
> leftover metal trim is scrapped. Since the coil is 41 inches wide,
> and only two 14 foot long by 15 inch wide, strips were cut, the
> remaining 14 foot long by 11 inch wide strip is scrapped.
>
> For some batches, the operator may consider dozens of 'reasonable' cut
> combinations before finally settling on one 'best' solution.
>
> I'm thinking that there is already a mathematical solution for this
> problem -- one that will accept input for the coil width, all the
> strips' lengths and widths, evaluate the possible cut combinations,
> then display the two or three that best minimize metal consumption.
>
> Any suggestions?

Yes - hire a mathematician as a consultant. Commercial operations
should be willing to pay good money for good advice.

--
Gerry Myerson (gerry(a)maths.mq.edi.ai) (i -> u for email)
First  |  Prev  | 
Pages: 1 2
Prev: proof of rearrangement inequality for >2 sequences?
Next: Applications of surface integrals