Presenting production losses to management: from percentages to hours and capacity

This article is for plant managers, production managers, continuous improvement leads and plant controllers who have to present production losses to an executive committee. The pattern is common: an OEE of 62% gets no reaction around the table, even though it hides hundreds of production hours a year. The aim here is to move from percentages to units that management handles every day: hours, weeks of production, capacity.

Why an OEE percentage is not enough for management

OEE is an excellent steering indicator for the shop floor. For management it raises three problems. First, it is abstract: 62% or 68%, the gap looks small while it represents many hours. Second, it invites debate: everyone has their own definition of planned production time, planned stops and reference speed, and the discussion drifts toward the calculation method instead of decisions. Third, it compares with nothing management arbitrates: a capital budget, a hire or outsourcing are expressed in hours, volumes and money, not in OEE points.

Translating OEE into hours does not change the measured reality. It changes the question asked of management: they are no longer asked to judge a percentage, they are shown how many weeks of production the plant loses and what it could do with them.

Translating OEE into lost hours

The basic calculation is simple. Equivalent productive hours equal OEE multiplied by planned production time. Lost hours are the difference between planned production time and those productive hours. The most useful step is then to split lost hours by major loss family, using measured rather than estimated data.

For example, take a fictitious line running two 8 hour shifts, 5 days a week, 46 weeks a year, which gives 3,680 hours of planned production time. The figures below are invented to illustrate the method. With an OEE of 62%, the line produces the equivalent of 2,282 hours at nominal speed and loses about 1,400 hours a year.

Presented this way, the message becomes clear: the line loses the equivalent of more than 17 weeks of production a year, including almost 6 weeks of micro-stops that nobody sees in reports.

Showing hidden capacity and comparing it with an investment

The second step is to express the possible gain as capacity. Still in this fictitious example, moving from 62% to 72% OEE frees 368 productive hours a year, about 4.6 weeks of two shift production. In volume, that is about 16% more output on the same line, with the same teams and no new machine, since 72 divided by 62 gives 1.16.

This is where the comparison with an investment becomes concrete. Faced with a new line, an extra night shift or outsourcing, management can ask the question in the same units: how many hours of capacity does this project bring, how fast, at what cost, and how many hours could be recovered from existing assets? The answer is not always the same. When the line is already well controlled, the investment is justified. When it loses 17 weeks a year, recovering part of that capacity is often faster and less risky. What matters is that the discussion uses comparable hours.

To stay credible, use cautious orders of magnitude. Plants equipped with TEEPTRAK gain on average 10 to 15 OEE points and cut unplanned downtime by 30% on average: these are averages, not promises for a given line. Present a low and a high range, and state the assumptions behind them.

Building a one page summary for management

Management reads a page, not a report. Here is a structure that fits on one page and answers the usual questions.

1. The key figure in hours. Lost hours per year on the scope, and their equivalent in weeks of production.
2. The split by loss family. A bar chart or a table, four or five families at most.
3. Recoverable capacity. Two scenarios (cautious and ambitious) expressed in hours, weeks and volume.
4. The comparison. Those hours set against an investment or outsourcing option already under discussion.
5. Three proposed actions. Each with an owner, a deadline and the indicator that will prove the result.
6. The data source. Automatic measurement or manual entry, period covered, definitions used. One line is enough, and it heads off half the objections.

Mistakes to avoid

• Presenting a plant wide average OEE. An average mixes very different lines and drowns the message. Show the bottleneck or the two or three lines that weigh most.
• Changing definitions along the way. If planned time or reference speed change from one month to the next, management compares different things. Freeze definitions and write them down.
• Adding up lost hours on non bottleneck machines. An hour lost on a machine that is waiting is not an hour of plant capacity lost. Capacity is reasoned on the constraint.
• Relying on incomplete manual entries. Micro-stops and slow running almost always escape manual sheets. An underestimated figure weakens the whole presentation the day someone really measures.
• Promising a gain without a plan. Hidden capacity without actions, owners and deadlines remains a hypothesis. Management funds a plan, not an observation.

What TEEPTRAK brings to this exercise

Converting into hours is only as good as the measurement. TEEPTRAK automatically measures OEE, downtime and micro-stops on each machine with a module wired into the electrical cabinet and a sensor at the line, with no PLC connection. Installation takes about one hour per machine and OEE is available within 48 hours. Lost hours by loss family then come from measurement, not estimates, so management sees figures whose origin nobody disputes. The solution runs in more than 700 plants in over 30 countries.

Further reading

• From OEE to unit cost: turning machine downtime into cost per part
• Cost of downtime: how to calculate your losses and protect your profitability

FAQ

Should losses be presented in hours or in money? The two complement each other. Hours are harder to dispute because they come straight from measurement. Money depends on margin or hourly cost assumptions that must be validated with finance. Starting with hours sets a solid base.

Which reference time should be used to convert OEE into hours? The one used to calculate OEE, usually planned production time (operating time minus planned stops). The key is to use the same reference for every line and every period.

How long should you measure before presenting figures? A few weeks of automatic measurement already give a reliable picture of loss families. For an annual presentation, extrapolate cautiously and state the period actually measured.