Steve,
You and production are getting hangup between line efficiency and operator efficiency. You are right when you record no downtime for the line. However, what you need to do is measure operator performance. In your situation the correct way to record this is to say no downtime for your
production line. However, one operator was working at say
89% efficiency because of equipment problem. This number has greater meaning if you have
an incentive system in place for each employee. By measuring operator performance ( or efficiency) on your line
you will be able to determine the manpower allocation for
this line. This information is important if you decide to
perform methods improvement in your line. You may find that
you can consolidate stations because operator utilization is
consistently below 95% for example.
The bottom line is how your Accounting Department looks at your labor. Production is interested in charging the time to downtime because at the end of the day direct labor has
to be engage in adding value to the the product or why do you need them?
Internal downtime ( which is what you experienced here)needs
to be record it and categorized ( what was the reason for the downtime)to be used for methods improvements. However,
it should not be turned into accounting because it was internal to the rate of your line. If you turn it into accounting, you basically are double barreling the cost(this term means counting the same thing twice in Accounting
jargon). Make sure your production department understand this or they are actually "shooting themselves in the foot" in their overall department manpower utilization numbers.