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Blog · Board and management reporting · Manufacturing

Downtime dashboard: lost time, causes and cost

A downtime dashboard compares stopped minutes, event frequency and potential production loss by machine and shift. A worked event log shows the calculations, cost assumptions and checks that prevent double counting.

The short answerA downtime dashboard measures when planned production stopped, how long each stop lasted and which causes account for the lost time. Group historical events by machine and shift, reconcile stopped and running time to the production schedule, and estimate output exposure using a documented production rate. Keep potential lost contribution separate from actual repair spending.

A downtime dashboard compares stopped production time, event frequency and potential output loss by machine and shift. Start with the historical event log and the production schedule, then separate the operational loss from the financial assumptions used to value it.

The useful result is a ranked set of operating questions: which causes consumed time, where they repeated, and whether the lost capacity affected orders. Stopped minutes alone do not answer all of them.

Set the production window before counting stops

An illustrative US component manufacturer reviews a day shift and a night shift on September 15, 2026. Machines A and B each have 480 planned production minutes per shift. Each machine therefore has 960 planned minutes, and the combined denominator is 480 × 2 × 2 = 1,920 machine-minutes.

The chosen window includes changeovers that occur during scheduled production. Breaks and other excluded periods have already been removed from the stated schedule. Keep this boundary visible beside the result; do not remove a stop from the numerator while leaving its time in the denominator.

Pacific Northwest National Laboratory's maintenance KPI guidance expresses availability as uptime over expected operating time, including planned downtime. It also distinguishes maintenance measures with different denominators. Your dashboard should state exactly which window its availability measure uses rather than relying on the label alone.

The production manager owns the schedule and reason categories. Maintenance confirms equipment-related causes. Finance owns any contribution assumptions. The shift supervisor checks that logged starts and finishes describe what actually happened.

A worked event log

Every event below occurs within its machine's scheduled production window. Times use the site's local clock. The rows do not overlap, and all events start and finish on the stated date. The expected rates are planning inputs for the product assigned to each machine: A makes 4 units per minute and B makes 3.

Event Machine Shift Stop Restart Cause Duration (minutes) Expected units/minute Potential units
E01 A Day 08:20 08:50 Material jam 30 4 120
E02 A Day 10:00 10:20 Sensor fault 20 4 80
E03 A Night 20:10 20:50 Material jam 40 4 160
E04 B Day 09:00 10:00 Material shortage 60 3 180
E05 B Night 19:00 19:30 Planned changeover 30 3 90
E06 B Night 22:00 22:20 Tool adjustment 20 3 60
Total 200 690

The duration is restart time minus stop time. Potential units equal duration multiplied by the expected rate for that event; E04 is 60 × 3 = 180 units. Summing the individual estimates gives 120 + 80 + 160 + 180 + 90 + 60 = 690 potential units.

This estimate describes capacity exposure during stops. It does not establish that customer orders were lost, that the expected rate was achievable throughout the shift, or that production was never recovered later. Keep actual accepted production beside the estimate when reviewing commercial consequences.

The machine and shift comparison

Running minutes = Planned production minutes - Stopped minutes

Availability = Running minutes / Planned production minutes

Average stop duration = Stopped minutes / Number of events

Machine Planned minutes Events Stopped minutes Running minutes Availability Potential units
A 960 3 90 870 90.6% 360
B 960 3 110 850 88.5% 330
Total 1,920 6 200 1,720 89.6% 690

Percentages are rounded to one decimal place after calculation. Machine A's availability is 870 / 960 = 90.6%; the combined result is 1,720 / 1,920 = 89.6%. Average stop duration is 200 / 6 = 33.3 minutes, also rounded to one decimal place. This average includes a changeover and a material shortage, so it should not be labeled mean time to repair.

Shift Planned machine-minutes Events Stopped minutes Potential units
Day 960 3 110 380
Night 960 3 90 310
Total 1,920 6 200 690

The day shift loses more time and more potential units. Machine A loses fewer minutes than B, yet more potential units because its planned rate is higher. That is why the production rate belongs in the event detail rather than applying one plantwide rate to every stop.

Availability is also only part of equipment effectiveness. The NIST report on manufacturing maintenance measures describes an OEE calculation using availability, performance and quality. This example has no measured running-speed or quality factors, so its availability percentage is not an OEE result.

Rank causes and show the financial assumption

Cause Events Stopped minutes Share of stopped time
Material jam 2 70 35.0%
Material shortage 1 60 30.0%
Planned changeover 1 30 15.0%
Sensor fault 1 20 10.0%
Tool adjustment 1 20 10.0%
Total 6 200 100.0%

Material jams lead on lost time: (30 + 40) / 200 = 35.0%. The material shortage is the longest individual event. These point to different review questions: repeated jams require a recurrence review, while the shortage requires an explanation of why scheduled material was unavailable.

Assume finance approves an illustrative contribution of $8 per additional unit sold for both products. Potential contribution exposure is 690 × 8 = $5,520. Contribution means sales less the incremental costs specified by finance; it is not the selling price. Use the manufacturing cost analysis to establish the cost boundary and keep actual repair expense in its own column.

Change one input: shorten the night jam

Change only E03's duration from 40 to 20 minutes, leaving event count, product rates, schedules and contribution per unit unchanged. The event now restarts at 20:30.

Measure Original case Shorter-stop case
E03 stopped minutes 40 20
E03 potential units 160 80
Combined stopped minutes 200 180
Combined running minutes 1,720 1,740
Combined availability 89.6% 90.6%
Combined potential units 690 610
Potential contribution exposure (USD) 5,520 4,880

The change releases 20 × 4 = 80 units of potential capacity and reduces exposure by 80 × 8 = $640. It does not eliminate an event: frequency remains 6. A spending decision still needs evidence that the released capacity serves demand and that the proposed fix costs less than its justified benefit; see manufacturing operational ROI.

Reconcile before the review

The schedule identity is 1,720 running + 200 stopped = 1,920 planned machine-minutes. Both the machine and shift tables must return 200 stopped minutes and 690 potential units. The cause table must return the same 6 events and 200 minutes. These are practical reconciliation checks, not optional display details.

Do not add machine-minutes together and call them elapsed plant downtime. These machines can stop simultaneously. If they are sequential steps on the same line, summing both output estimates can also count the same lost production twice; estimate the line's constrained output separately.

Where it goes wrong

  • Overlapping event rows. One stopped interval with several logged causes must not be counted repeatedly. Split the interval or assign a primary cause under a written rule.
  • Different schedule boundaries. Excluding changeovers from one machine and including them for another makes the availability comparison inconsistent.
  • One production rate for every product. Apply the rate appropriate to the machine and product at the time of the stop.
  • Opportunity labeled expense savings. Potential output is not an incurred bill or guaranteed lost sale. Keep recovery, demand and actual repair cost separate.

Analyze your downtime log in Covirage

Upload the event log, production schedule and approved rate assumptions. Covirage maps the columns; its tools compute and check the figures, and the external AI model explains the results with every figure traced to its rows. Create a free Covirage account, which takes about a minute, then set up your business and bring a sample of your own data.

See Covirage for industrial manufacturers for the wider operating and financial review.

Questions people ask

What is the difference between downtime and availability?

Downtime is stopped time within a defined operating window. Availability expresses running time as a share of the planned production time in that window. The same downtime duration can produce different availability results when machines have different schedules, so show both the minutes and denominator.

Should planned changeovers appear on a downtime dashboard?

Include them when they occur inside the production window you have chosen, and label them separately from unplanned failures. Exclude time outside that window consistently. A change in the treatment of changeovers can move the reported availability even when the operating events are identical.

How do you estimate downtime cost without overstating savings?

Estimate potential output using stopped minutes and a justified production rate, then apply the contribution per unit. Label the result as exposure. Confirm demand, bottleneck effects and later recovery before calling it lost profit, and record repair spending separately from the opportunity estimate.