Hi,

I have a costing workbook whereby different costing worksheets vlookup steel prices that are tabled in their own worksheet.
To estimate a project, we copy some of the costing worksheets (as many as we need for that particular project) out into their own workbook.
The steel costs still refer back to the original workbook, so it works great.
However after enough time has passed (usually months) the steel cells return the #NA error.
I suspect this could potentially be to do with during this time, we've changed something on the steel cost table, whether it be adding a column, row, steel size etc. but not really sure.

If this is the case, is there any way we can prevent this from happening (i.e. locking once copied or a better link)?
it is quite painful to have to manually re-enter steel costs once you have won a project or it comes back out for re-pricing.
Ideally when this happens we would open the original project workbook to automatically updated steel costs and be able to see current margin for that job.


Cheers