Calculating OEE Performance Measurement for a CNC Plasma Cutter

[marcelbakker7]

Hello everyone,

First of all thank you to everyone who has posted on this forum, its very usefull. Despite that a lot of information is on this forum I could not find a particular thing. I am doing an internship at a company wich cuts and forms sheet metal. My job is to implement TPM. One of the things I am working on now is a OEE (overall equipement effectiveness) measurement for a cnc plasma cutter. The cutter cuts different parts out of 1 piece of sheet metal.The thing is that I cant figure out a way to calculate the performance rate because every product is different. Does someone know a way to calculate the performance rate in this case?

Thanks in advance,

Marcel Bakker

 

[Stijloor]

Good Morning Marcel,

Welcome to The Cove Forums!

An advanced search on "OEE" revealed these results.

Some more "clicking" is necessary, but at least this will help you to get started.

Stijloor.

 

[marcelbakker7]

Good morning Stijloor,

Thank you for your reply. Unfortunatly i can't find the awnser to my question with the search. The point is that I have no reference point to calculate the performance rate. This is because the cutter cuts different tonnages and parts every day. For example:

monday: 200 parts out of 20 pieces of metal of 20mm thick
tuesday 500 parts ouf of 40 pieces of metal of 8mm thick

The machine can cut faster on less thick metal so it can produce more parts/products with thinner plates. also the weight cant be a refference point because out of the one plate we'll cut 1 part and the other for example 20 (wich takes longer but might weigh the same).

 

[Stijloor]

Marcel,

Thanks for the additional information. I do not claim to be an expert on OEE. Today is Labor Day, many folks have the day off, but I am sure that you will get responses soon. I was just trying to "get you going." I'll do some more research.

BTW, I found a calculator - ***DEAD LINK REMOVED***.

Stijloor.

 

[marcelbakker7]

Stijloor,

Thanks for trying, I appreciate the help and every bit of extra information is more than welcome. Happy labor day to you all i guess ;-)

Marcel

 

[Claes Gefvenberg]

Hello Marcel, and welcome to the Cove

The thing is that I cant figure out a way to calculate the performance rate because every product is different

You may have to go for an average then.

With OEE = No. of good parts produced / No. of parts teorethically possible to produce you would need to select a timeframe long enough to even things out. I am NOT an OEE expert either though, so I would like to get a 2:nd opinion on that.

BTW, I found a calculator.

Yeah! That looks interesting. Good link: I bookmarked it right away.


/Claes

 

[marcelbakker7]

Hello Marcel, and welcome to the Cove You may have to go for an average then.

With OEE = No. of good parts produced / No. of parts teorethically possible to produce you would need to select a timeframe long enough to even things out. I am NOT an OEE expert either though, so I would like to get a 2:nd opinion on that.

Yeah! That looks interesting. Good link: I bookmarked it right away.


/Claes

Hello Claes,

Thanks for replying. I thought of taking an average too, but i'm not an OEE expert either so if anyone can confirm that it is OK to do or if anyone has another idea please do post!

@stijloor:
Thanks for the link, pretty usefull but unfortunatly I cant fill in the value "Theoretical maximum output per hour" (or if an average is OK to do, I could ofcourse fill in that...)

 

[prototyper]

You may have to be creative and devise another measure rather than number of parts. For example, total time spent cutting against total available time.

This could be easy to collect if the CNC cutter has software with timers.

 

[marcelbakker7]

You may have to be creative and devise another measure rather than number of parts. For example, total time spent cutting against total available time.

This could be easy to collect if the CNC cutter has software with timers.

Thanks for your reply, I thought of that too, but if you take the time spent cutting you wont catch the times when the machine is cutting on a lower speed. Cutting speed might be a possible measure point, but the machine also has a printer and 3 movable tables so you wont measure the whole machine. You can ofcourse measure all those 3, but technichaly its not possible to let the cutter log the speeds so the operator has to write it all down wich will cause more slowdown to collect the data than it will produce

 

[somashekar]

Hello everyone,

First of all thank you to everyone who has posted on this forum, its very usefull. Despite that a lot of information is on this forum I could not find a particular thing. I am doing an internship at a company wich cuts and forms sheet metal. My job is to implement TPM. One of the things I am working on now is a OEE (overall equipement effectiveness) measurement for a cnc plasma cutter. The cutter cuts different parts out of 1 piece of sheet metal.The thing is that I cant figure out a way to calculate the performance rate because every product is different. Does someone know a way to calculate the performance rate in this case?

Thanks in advance,

Marcel Bakker

I will see it this way ...
OEE is the time the machine is actually performing its task taken over 24x7. The premise is that unlike men, machine can work 24x7. Now we have two other things, the setup time and the down time. Once you have the OEE calculated over a spread time, then to improve upon it several steps can be initiated, which primarily aims at eliminating the various causes of the down time, reducing the setup time and then optimizing the working time. It is in this optimizing exercise that you apply the principles of manufacturing technology.