Norm speed: aren’t you wasting your potential?

Which speed is your norm speed when you want to measure your performance in OEE? Are your goals ambitious enough? Improvement consultant René Kindervater talks about using your machine’s true potential and your process with the correct norm speed.

René Kindervater: “The norm speed is at the basis of all measurements. You can only measure your performance rate with a clear norm speed. But which norm speed do you choose?

Determining the norm speed

“The function of a norm speed is that you have a zero point. As with OEE, at first it doesn’t matter if it’s at 10% or 60%, it’s important what happens next. How do we start with continuous improvement, and how do we make the line run better?

You have to set a standard value for your machine speed. What can this machine do? The machine supplier often gives you a value already, such as a printer’s capacity to make 40 prints per minute. But the situation isn’t always that clear, or as ideal.

The norm speed is a zero point. What’s important is: what happens next?

Suppose that you work with different raw materials than in an ideal situation. The machine will then run at a lower speed. Or you work with older machines. Then, the manufacturer’s norm speed isn’t relevant anymore. Because the machine has been tuned on the work floor, has been pimped, boosted, and runs at a much higher speed than when it came from the factory. That would be the best situation. The Japanese say that at delivery, a machine is in the worst condition ever. Because from day one, the users will start to improve the device.

It might also be that you manufacture different products on one machine. Do you still focus on the machine speed or the norm speed per product?

Norm speed per product

“Determining a norm speed for every product is quite the administrative hassle. You have to measure, test, and document everything. The amount of work depends on how many different products you manufacture.

In itself, it’s fair, of course. When a specific product requires an extra action or runs at a low speed because it needs different raw materials, you will never reach the machine’s norm speed.

Do you realize that when your fastest product disappears, so does your highest norm speed? So what do you do? Is your machine suddenly incapable of working at that speed, and do you adjust to a lower norm speed?

The biggest drawback of a norm speed per product: you give away part of the potential.

This is immediately the biggest drawback of a norm speed per product: you give away part of the potential. Because the machine can run at a given speed. But as an organization, you choose to lower that speed for certain products. When you set up the norm speed per product, you accept that the machine doesn’t run optimally. You don’t even see it anymore. As soon as you take the loss into the equation, it’s gone. And you’ll never address it again.

Using your potential with the correct norm speed

“If you want to use your true potential, you have to visualize it every time: this line with these products doesn’t reach the norm speed of the machine. But if you set the norm speed per product, the performance level is always high, probably around 100%. And you will stop paying attention to it. 

It’s different when a product runs at a low speed continuously or when the performance level fluctuates. You keep getting questions: why is the speed so low? And you start to wonder: do we want this, or do we want to change something in the product of process so we do reach that speed? Or can we ensure that sales sell more products that we can manufacture optimally? Then you are actually busy using your potential.”

How do you define the optimal norm speed?

“First, consider whether you want to work with a norm speed per product or a norm speed per machine. You can’t change the variables during the game, so you can’t just change the zero point anymore. Think in advance about what you choose.

Actually, determining the norm speed is something best done live. From a LEAN perspective, you measure the time the machine actually changes the product and adds value to it. You can take a stopwatch and start measuring at the line. Not just once, but preferably 20 or 100 times, because the more samples you collect, the lower the deviation is. If, for example, the time is 6 seconds, then you can let 10 products per minute pass by. That will be your norm speed.

Of course, you can cross-check those results with your software data, but with a live count, you know what you’ve measured much better. Because does the sensor actually measure? Is it really the processing time you have in mind? With a manual count, you know exactly what it’s about. And if there’s a significant difference between the measuring methods, then you can start asking questions about that too.” 

Norm speed as part of continuous improvement

“If you start with continuous improvement, you don’t just look at the norm speed, but at all factors in your process: availability, performance, quality. Based on that, you can make decisions to improve your process.

With all improvement actions, you can only make choices when you the measurements are available.

For example, some companies can run certain products on several machines. You can determine which device is best for running that product, based on speed. That choice can also be related to the machine changeover time. If it takes a lot of work, you may benefit less from having a higher speed on that line.

And if the performance rate varies a lot, you want to know the cause - and what you can do about it. Suppose you make cheese. And the temperature in the hall fluctuates. You can't slice the product very well if it’s very hot. So, you could also be dealing with seasonal effects. Or with one operator taking more time for checks than his colleague.

With all improvement actions, you can only make choices when the measurements are available. And if you know what you are measuring and why. An optimized norm speed is at the basis of that process.”

René Kindervater and his colleagues at KSL-Solutions use Cierpa Software to get the most out of their clients’ improvement projects. Contact Cierpa or KSL-Solutions and take a look at the opportunities for your organization!