OEE for Blister Packaging Lines: Rates, Changeovers and Counts

A blister line looks like one machine from the corridor. On the floor it is nine stations tied together by a web of film and a very short buffer.

That is why generic OEE advice fits it badly. The line runs in cycles, it counts in two units, and a batch change can take longer than the batch.

This page shows where a blister line loses time, speed and product, how to set its rates, and what to ask of OEE software. We sell Fabrico, so test our claims like any other vendor's.

The blister line, station by station

The sketch shows the usual order and the loss each station is known for. Your line may differ, so walk it once with this list in hand.

The blister machine sets the pace. The cartoner is usually set up to run a little faster, so it waits for blisters and not the other way round.

The buffer between the two is small. A cartoner jam soon backs up and stops the blister machine, and the blister machine's log then shows a stop it did not cause.

So record which station stopped first. Without that, the downtime chart blames the wrong machine.

The ideal rate: cycles per minute times blisters per cycle

A blister machine does not run in blisters. It runs in forming cycles, and each cycle makes a fixed number of blisters set by the format tooling.

So the ideal rate is two numbers multiplied. Example: 40 cycles a minute times 5 blisters per cycle is 200 blisters a minute, or 0.3 seconds per blister.

Set it for each format. A deep pocket or a large blister runs fewer cycles, and the number of blisters per cycle changes with the tooling.

The builder's figure is a ceiling, not your rate. Uhlmann, for one, lists a maximum output of 250 blisters a minute for its B 1240 and up to 500 for its B 1440.

For each format, use the best cycle rate the line has held steadily with good product. Three traps are common:

• One rate for all formats. Slow formats then look like bad shifts.
• The cartoner's rate as the line rate. It is in cartons, and it is not the constraint.
• Cycles counted as output. During start up the machine cycles while the blisters go to waste.

Availability: format changeover and line clearance come first

On most blister lines the longest stops are planned ones. A batch ends, the line is cleared, and often the format parts change too.

Time the changeover from the last good blister of the old batch to the first good blister of the new one. Then split it, because each part has a different owner:

• Run out and count: emptying the feeder and reconciling materials.
• Line clearance: removing product, foil, leaflets and cartons of the old batch, and the check by a second person.
• Format parts: forming, sealing, perforation and punch tooling, feeder parts, cartoner size parts.
• Waiting: for sign off, for materials, for a fitter.
• Start up: heat up, settings, first good blisters and cartons.

A batch change on the same format has clearance but no format parts. Give it its own code, or your changeover average will mean nothing.

We keep changeover inside planned time, as a planned stop that lowers availability. Some plants take it out of planned time instead.

Both work if the rule is written down. But if you take it out, the biggest loss on a short batch line leaves the chart, so still report its minutes for each batch.

Our page on line clearance covers the procedure itself. What the plant must do there is set by its own quality rules, not by the OEE system.

The unplanned stops are more familiar: web tracking faults, a torn film, a sealing fault, a jammed punch, and reel changes on machines with no automatic splicer.

Performance: short stops and turned down cycles

The speed loss on a blister line mostly sits after the blister machine. Leaflet feeders miss or double feed, a carton fails to open, a blister stack tips at the cartoner infeed, a printer runs out of ribbon.

Each one takes seconds to clear, and an operator clears dozens in a shift. Stops under your threshold count as micro-stops, and they land in performance.

Nobody writes them on a sheet. They only show up when the stop comes from the machine signal, with the station attached.

The second speed loss is quieter. When a tablet is dusty or the feeder struggles, the operator turns the cycle rate down, and it often stays down for the batch.

Compare actual cycles per minute with the ideal for that format, hour by hour. For the cartoner's own faults, see our page on cartoner losses.

Quality: empty pockets, splices and start up blisters

The blister machine's own inspection camera looks at each pocket before sealing. One empty pocket or one broken tablet rejects the whole blister.

That is why feeder gaps are a quality loss and not a speed loss. The machine keeps cycling at full rate, and the reject bin fills.

Four more sources belong on the list:

• Foil splices. Blisters that carry a splice in the forming film or lidding foil are typically rejected.
• Restart blisters. After a stop, many lines reject the blisters that sat in the heated forming and sealing stations.
• Carton rejects. The print station rejects codes it cannot read. The checkweigher throws out cartons short of a blister.
• False rejects. A camera set too tight rejects good blisters. Track the reject rate by format to see it.

Some plants recover tablets from rejected blisters and feed them back. For OEE the blister is still a reject, because OEE counts what was right the first time.

Count blisters or cartons? Both, in one unit

A blister line has at least five places where something is counted. They answer different questions.

Use good cartons past the checkweigher as the line's good count. Multiply by blisters per carton to get back to blisters.

Do not compare cartons per minute across formats. A pack of three blisters makes a third of the cartons of a single pack, at the same blister output.

On older cartoners and case packers the count is sometimes hard to reach, or the plant does not want the machine program touched. A camera that counts parts on the outfeed conveyor is one way to get that number.

That is a different camera from the inspection camera in the blister machine. It counts cartons or cases and does not inspect tablets.

Worked example: one shift, one format change

These are example numbers and describe no real plant. The shift is 480 minutes with 30 minutes of breaks, so planned time is 450 minutes.

The format runs at 40 cycles a minute and 5 blisters per cycle, so the ideal rate is 200 blisters a minute. Each carton holds 2 blisters.

Availability is 315 of 450 minutes, or 70%, and performance is 50,400 of 63,000, or 80%. Quality is 47,880 of 50,400, or 95%.

Multiply them: 0.70 x 0.80 x 0.95 = 53.2%. Now check it the short way: 47,880 good blisters at 0.3 seconds each is 239.4 minutes, and 239.4 of 450 is 53.2%.

The changeover alone is 90 of the 135 stop minutes. The 63 minutes of speed loss are the short stops and the turned down cycles together.

The full method is in our guide to OEE calculation.

What to check in OEE software for a blister line

Run these seven checks in each demo, ours included. They hold for any OEE software.

1. Ideal rate by format. Change the format in the demo. Does performance follow the new cycles and blisters per cycle?
2. Two units. Enter blisters per carton for two pack sizes. Check the blister total by hand.
3. Changeover in parts. Can one changeover be split into clearance, format parts, waiting and start up, and compared by format?
4. First station to stop. Take a cartoner jam. Is the blister machine shown as blocked, or as stopped by its own fault?
5. Short stops. Ask for the threshold, and for short stops listed by station.
6. Rejects by source. Are inspection camera, checkweigher and print station rejects kept apart? Does each come from a signal or from typing?
7. Planned time rule. Ask to see changeover inside planned time and outside it, and where the rule is shown.

Where Fabrico fits

Fabrico is a cloud-based OEE and light MES platform, on the web, iOS and Android.

• Stops: they come from the machine signal, through the PLC or a Fabrico IoT device. The operator adds the reason on a tablet or phone.
• OEE and downtime: availability, performance and quality by line and by shift. Micro-stops are detected from the machine signal.
• Losses in money: not only in minutes.
• Counting: the AI camera is an add-on that counts parts. You can open the video of a stop. In the standard setup, video is streamed, not stored.
• Your data: REST API, webhooks, and any list exports to Excel or CSV.
• Not in Fabrico today: production planning and scheduling.

A stop reason can also be set up to open a maintenance task.

Batch records and batch release stay in your quality systems. Ask every vendor, including us, what their system is meant for and what it is not.

Book a demo or Contact us.

What people ask next

What is a good OEE for a blister line?

We know of no public benchmark we would trust for blister lines. Batch size drives the number, since a line with many short batches spends much of its time in changeover.

Compare the line with itself, by format and by batch size.

Should line clearance count against OEE?

We count it, inside changeover, as a planned stop that lowers availability. If your plant takes it out of planned time, still report the minutes for each batch.

Should the blister machine and the cartoner have separate OEE?

Measure both, but report one line OEE. Use the blister machine's ideal rate and the good cartons at the end, in blisters.

Machine figures are for finding which station stopped first.

Do recovered tablets count as good product?

Not in OEE. The rejected blister is a quality loss even if the tablets are fed back, and the recovery work is a cost of its own.

Do we need a full MES to measure this?

Not for OEE and downtime. Machine signals, counts and stop reasons are enough, and a light MES covers them.

Want to run the seven checks on us with your own format list? Book a demo or Contact us.