As a case study,I'm trying to come up with an effective measure of work productivity for a file handler. The file handler receives new files every month, and closes files every month. The amount to new files asssigned vary greatly from month to month. The files closed also vary greatly from month to month.

I'm trying to come up with an effective measure of file handler productivity by looking at the following categories on a monthly basis:

*New open file count
*Current open files
*Prior month open file count
*Total file closures for the month

How would you suggest that an effective measure of productivity be measured? I would really appreciate any feedback you could provide. Thanks!