How to consider OEE

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Fred E asked Jul 11, '22 Felix Möhlmann answered Jul 11, '22

How to consider OEE

Hi!

Machines don't work constant all the time, so I want to take into account OEE in % in process time.

I am looking to make the processor OEE to be 87%.

I know that OEE is calculated from availability %, performance% and quality %. But for now I want just that my process time is not 100 % all the time.

With which statistical distribution should I consider the percentage of OEE in process time. Additionally, I use a global table to set the processor's processing time.

My model: model10.fsm

Software Version:

FlexSim 21.2.4

global table process time oee

model10.fsm (31.1 KiB)

Answer 1 · 2022-07-11T11:25:11Z

Felix Möhlmann answered Jul 11, '22

There isn't really a general answer to this, because there are many ways of how that final number of 87% might have been reached. The machine being completely stopped for 13% of the time will likely have different repercussions in the model than it running continuously but with a 15% higher process time.

If you only want to alter the process time and not incorporate stops, an exponential distribution with a mean value of the average process time including OEE might be a good starting point.

double defaultVal = Table("GlobalTable1")[1][2];
double OEE = Table("GlobalTable1")[1][3]/100;
double expScale = defaultVal * (1-OEE)/OEE;

return exponential(defaultVal, expScale, getstream(current));

(You can also type this into the process time field as one expression, but it gets rather lengthy, so I broke it up into multiple lines of code.)

model10_fm.fsm

model10-fm.fsm (32.0 KiB)

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