Calculation of DPMO

Ultimately you’ll be calculating DPMO by dividing the total number of defects by the total number of opportunities (for a defect), and then multiplying by 1,000,000.
The toughest task is to assess your process(es) and determine the number of opportunities for defects per unit of work (OPU) (for us it is per product). You need to honest and realistic. Consider the potential places in your process where a defect can occur, but don’t start adding all the different kinds of defects.
For an electronic PC board we tend to use Opps = # of parts + # of electrical connections. For completion of forms, you might count the number of fields to be filled out (don’t worry about all the different ways a field could be filled in wrong). It might be the number of steps taken to complete the task.
Now, start tracking the number of defects per unit, or start summing up the total number of defects and track the total number of uits. To calculate an average defects per unit (DPU) you can just divide the total number of defects by the total number of units.
DPMO = 1,000,000*DPU/OPU
             = 1,000,000*Total Defects / (Total Units *OPU)

In my openion, first you need to quantify the ‘efforts spent’. For the existing process, you may collect the data on efforts spent and rank them based on the input. Then fix the specificantion limits.
Best of Luck.
Shirish
 

You are going to have to list the tasks and efforts needed to write the reports.  Any delays or rework are going to be your defects.  I would think that gathering the data for the report would provide several opportunities for defects (missing data, late data, inaccurate data…).

Instead i would use the yield as a metric for this process. DPMO is not really the good metric in that kind of project/objectives You need to know what  your customer wants!! reduce it to 80 hrs on average or 80 becomes the upper spec? Once you’ll know, assess your process and put the upper spec limit. Everything that is beyond the usl are defects. You’ll then be able to conduct some statistical analysis and determine what proportion is over a specific value.