Can someone help me figure out the increase/decrease in production based on turn around time?

I'll explain:





Let鈥檚 say Joe completes an average of 500 units at 1 day turnaround time for the month of January. For the month of February, his volume increased to 800 units and his turnaround time also increased to 1.6 days. Then in March, the volume decreased to 400 units for the month and his turnaround time was at 1 day.





How do I figure out the increase or decrease of his performance? Did his increase/decrease in volume match the increase/decrease in his turnaround time?Can someone help me figure out the increase/decrease in production based on turn around time?
Monthly production increase or decrease can be


calculated using the formula: (subsequent production less initial production)/initial production multiplied by 100. This will give you the increase or decrease in


%. Thus from Jan to Feb, the %increase in production was 100(800-500)/500=60%. For Feb to Mar it was


100(400-800)/800= -50%, meaning that his production


decreased by 50% over the previous month.





If you use 500 units and 1 day TA (turnaround time) as a standard, then for 800 units the matching TA should be


500:1=800:TA or TA=800/500 =1.6. His actual TA was the same. Therefore the increase in volume matched his TA.





For 400 units his matching TA should be 500:1=400:TA or


TA=400/500 =0.8 day. His actual TA was 1 day. Therefore the decrease in volume didn't match his TA.