Measure parts per hour, labor efficiency, throughput, utilization and estimated production capacity for fabrication work.
Estimate potential output from the current productivity rate and future available production time.
These metrics measure different aspects of production. A shop can have good utilization but poor efficiency, or high labor efficiency while still having low utilization because machines or operators spend substantial time waiting.
Parts per hour is a straightforward throughput measure. It indicates how many completed parts are produced during one productive labor hour.
For example, if a team completes 120 acceptable parts in 80 productive labor hours:
For comparisons between jobs, keep the definition of productive hours consistent.
Labor efficiency compares the labor time that should have been required under an established standard with the actual labor time used.
For example, if the standard labor time for completed work is 75 hours and the actual labor time is 80 hours:
An efficiency above 100% means the work took fewer actual hours than the standard. An efficiency below 100% means the actual labor requirement was greater than the standard.
The standard must be realistic and consistently defined. Changing the standard can change the reported efficiency without changing actual production.
Utilization measures how much of the available scheduled time was spent productively.
Lost time can include material shortages, machine downtime, waiting for inspection, setup, maintenance, meetings, rework and other non-productive activities.
Utilization and efficiency should be viewed together. Improving one does not automatically improve the other.
Throughput describes the amount of acceptable finished work produced during a defined period. For fabrication shops, this can be measured in parts, assemblies, kilograms, tonnes, meters or another appropriate production unit.
Parts per hour is useful when the parts are reasonably comparable. If jobs vary substantially in complexity, labor hours per part or standard hours completed may provide a better comparison.
Completed parts and accepted parts are not necessarily the same. Rejected or reworked pieces consume labor and material but may not count as finished saleable output.
Tracking good-part throughput prevents production metrics from appearing stronger simply because rejected work is included in the output count.
Productivity comparisons are most useful when the jobs being compared have similar complexity and the same measurement definitions are used.
The capacity section uses the measured productivity rate and applies expected utilization, efficiency and yield assumptions to estimate future good-part output.
This is an estimating model rather than a guaranteed production forecast. Actual capacity can be constrained by bottlenecks, material availability, machine capacity and job mix.
How do I calculate parts per hour?
Divide completed parts by productive labor hours used to produce them.
What is labor efficiency?
Labor efficiency compares standard labor hours for completed work with actual labor hours used.
What is the difference between utilization and efficiency?
Utilization measures how much available time was productive. Efficiency measures how actual labor time compares with the established labor standard.
Should rejected parts count as production?
For a quality-adjusted productivity metric, accepted good parts should be tracked separately from total completed parts.
Can productivity be measured for welding?
Yes. Welding operations can use parts per hour, weld length per hour, deposited metal per hour or standard labor hours depending on the job.
Can I compare two fabrication workers using parts per hour?
Only when the parts and working conditions are sufficiently comparable. Different part complexity can make raw parts-per-hour comparisons misleading.
What causes low fabrication utilization?
Common causes include machine downtime, material shortages, setup time, waiting, inspection delays, maintenance and non-production activities.
How can I improve productivity?
First identify the largest time losses or bottlenecks. Improvements can involve material handling, fixtures, job sequencing, machine availability, layout, training and process standardization.