Problems with Formulas
 

I currently have a pivot table that shows the total number of parts at a
specific operation, per week and against specific machines

What I have done is inserted a formula into the pivot table to calulate the
production time by week against the specific machines using the hourly rate.

The problem is that when data is made up from more that 1 result. ie 2
diferent order no.s but for the same operation on the same machine and during
the same week, it is dividing the answer by 2. It also divides it by 3 if it
is made up from 3 results, and so on. obviously the only result that is
right is when data is from only 1 result.

How can I get the fomula to just calulate the production time by week
against the specific machines using the hourly rate.

Thanks in advance