Manufacturing downtime: measure the losses before automating

Manufacturing downtime is time when a process expected to produce is not producing. Before buying a robot to recover it, establish why the process stopped. Waiting for an operator, waiting for material, changing tooling, and repairing a machine require different remedies.

A useful downtime study ends with a purchase specification: which losses the proposed cell will address, how much time remains outside its control, and how the team will confirm the improvement. It should also reveal simpler fixes worth completing before installation.

Define the clock before collecting data

Choose the machine or cell boundary and define scheduled production time. Record planned breaks and planned maintenance consistently instead of changing the denominator to improve a report. Preserve raw start and end timestamps so another person can reproduce the totals.

The Lean Enterprise Institute's OEE explanation separates availability, speed, and quality losses. That distinction helps avoid describing every missing unit as downtime. A machine running slowly and a machine standing still may produce the same daily shortfall but need different interventions.

Build a loss log operators can actually use

Begin with a short reason list: equipment fault, no incoming material, blocked outgoing material, setup, quality hold, staffing wait, and unknown. Review unknowns together at the end of the shift. A detailed classification nobody uses is less useful than a simple log with reliable timestamps.

NIST's maintenance economics research examines the data needed to estimate maintenance losses. For your buying decision, retain the observations behind every claimed recoverable hour.

Match each loss to a plausible intervention

If a CNC machine waits for unloading, a tending cell may help. If its cutting tool repeatedly fails, a loading robot does not repair that problem. If the robot will simply wait for the same missing blanks, the automation proposal needs a material-supply change as well.

Review supporting utilities before deciding that the arm is the bottleneck. The Department of Energy's compressed-air maintenance resources cover pressure stability, leaks, and air quality. Ask maintenance to check the relevant plant conditions when pneumatic clamps or grippers behave inconsistently.

Use the machine tending business-case guide for operator waiting losses and the material handling selection guide when starvation or blocked transfers dominate.

Estimate recoverable time conservatively

Consider a hypothetical shift with 90 lost minutes: 35 waiting for load/unload, 25 in changeover, 20 in equipment repair, and 10 without material. A supplier proposes recovering 25 of the load/unload minutes and five changeover minutes. The initial opportunity is 30 minutes, not the entire 90.

If the demonstrated process produces one accepted part every two minutes, that time could support 15 additional parts before accounting for new automation interruptions. Confirm the remaining process can use the capacity and that demand exists. Do not multiply the 15 parts by sales price and call the result profit.

Run a conservative case with more replenishment and recovery time. A sound proposal should describe how those assumptions change when the part mix or staffing pattern changes.

Put recovery into the acceptance test

• Measure accepted output over a realistic operating window, including replenishment.
• Record each stop and the time until normal production resumes.
• Test a missing part, full output tray, and approved restart sequence.
• Verify operators can identify the fault and follow documented recovery instructions.
• Include changeover between representative products, not only repeated cycles of one sample.

Keep a baseline and post-installation log using the same definitions. Use the automation business-case worksheet to value verified improvements. Preserve your loss categories and sample shift records as evidence for the proposed scope.

Turn loading delays into a FAIRINO application brief

When your log shows repeated waits for loading or unloading, put a FAIRINO machine tending cell on the improvement shortlist. Compare the FR5 and FR10 against the combined part-and-tool load, machine access, and tray positions. The proposal should target the delays you measured and include a recovery plan. Request a FAIRINO tending quote with a shift log and machine layout so the purchase decision connects directly to recoverable production time.