What is Utilization? Definition & Manufacturing Examples

What is Utilization?

Utilization in manufacturing measures the percentage of available production time that a resource — machine, work center, or labor group — actually spends on productive work. If a CNC mill is available for 80 hours per week and spends 64 hours running production jobs, its utilization is 80 percent. Utilization is one of the most widely tracked manufacturing metrics, but it is also one of the most misunderstood. Higher utilization is not always better.

How Utilization Works in Manufacturing

Utilization is calculated as:

Utilization = (Actual Production Hours / Available Hours) x 100

Production hours include setup time and run time — the time the machine is occupied with a production order. Available hours represent the total time the resource is scheduled to work, typically based on shift patterns minus planned maintenance.

Time not counted as productive includes idle time (machine available but no work assigned), unplanned downtime (breakdowns, missing materials), and non-production activities (training, cleaning, meetings).

The relationship between utilization and queue time follows an exponential curve. At 70 percent utilization, average queue time might be 4 hours. At 85 percent, it doubles to 8 hours. At 95 percent, it quadruples to 16 hours or more. This is the same mathematical phenomenon that causes traffic jams when highway utilization approaches 100 percent.

This means that pushing every resource to 95 percent utilization actually hurts overall performance. Queue times explode, lead times balloon, WIP inventory increases, and schedule flexibility disappears. The only resource that should run near maximum utilization is the bottleneck. All other resources should maintain some slack capacity to absorb variability and provide scheduling flexibility.

Utilization Example

A machine shop tracks weekly utilization across its CNC department:

CNC Mill 2 at 95 percent utilization has a 22-hour average queue — jobs wait almost 3 shifts before being processed. The 5-point difference between Mill 1 (90 percent) and Mill 2 (95 percent) results in nearly double the queue time. This illustrates why a planner should move some milling work from Mill 2 to Mill 1 or even to the lathes (if capable), even though it means "underutilizing" other resources.

The shop's overall utilization of 80 percent looks healthy in aggregate, but the imbalance creates a poor customer experience for any job that needs CNC Mill 2.

Why Utilization Matters for Production Scheduling

Utilization data is essential for scheduling decisions, but it must be interpreted correctly. The goal is not maximum utilization everywhere — it is optimal utilization that balances throughput, lead times, and schedule flexibility.

Resource Manager DB (RMDB) provides real-time utilization reports for every resource, showing both current and projected utilization across the scheduling horizon. Planners can identify overloaded resources, spot underutilized capacity for new orders, and make informed decisions about workload distribution. The visual loading charts make utilization imbalances immediately apparent.

Related Terms

• Loading — The process of assigning work to resources that determines utilization levels
• Bottleneck — The resource with the highest utilization that constrains overall throughput
• Capacity Planning — The strategic process that uses utilization data to make resource investment decisions

Frequently Asked Questions

Learn more in our complete manufacturing glossary or production scheduling guide.