OEE (Overall Equipment Efficiency) - One question

[Sharpin Zou]

For OEE measurement, i saw some sites use the planned work days as the total availiable run time (TART), e.g. 20 days a month (instead of 30/31 days a month), especially during the encominic recession period or a new facility. Is this correct (or say popular) for measuring the OEE??

 

[somashekar]

Re: One question regarding OEE

OEE .. The O is overall and the overall TART is best taken as 24 hrs x 7 days. Anything less is hiding from reality. Unlike human, the Equipment is there up for us to make use of to our best capacity, and to suitably maintain it. In this TART of 24x7, you also get to know how much is loss due to lack of shifts to cover 24 hrs work, loss due to holidays and everything else in between. You hence get all the opportunity to improve the OEE.

 

[Sharpin Zou]

Re: One question regarding OEE

OEE .. The O is overall and the overall TART is best taken as 24 hrs x 7 days. Anything less is hiding from reality. Unlike human, the Equipment is there up for us to make use of to our best capacity, and to suitably maintain it. In this TART of 24x7, you also get to know how much is loss due to lack of shifts to cover 24 hrs work, loss due to holidays and everything else in between. You hence get all the opportunity to improve the OEE.

Agree with your opinion. Thanks. For those using planned work days as TART, instead of focus on capacity i think (due to plenty of capacity in a new factory) they may use OEE to drive for the performance index and quality index improvement. I mean they may focus on performance and quality at this stage by measuring OEE. I am not sure if this is correct.

 

[palmer]

I don't think that using 24/7 is accurate in the "real" world.:mg:

I believe most work environments do not run 24/7 so efficiency based on this number is not realistic. It also depends on who is using this information. Schedulers would misinterpret this info and say that the work being performed is not being done efficiently. Higher ups would say that the employees running the facility are doing a poor job and the workers don't deserve raises or perks for running good due to poor effieciency.

Also, this measurement means you would NEVER come close to 100%. So your 100% would become 75%-80%. This creates a mentality of not worrying about doing the best you can because you will never come close to attaining 100%.

We have annual reviews rated at 1 to 5. You can never achieve a 5. 3 is our 100%. It leaves a bad taste in your mouth because if you achieve 4-5 then your boss was favoring you or your goals were not high enough.


In a nutshell- be careful who has access to this information because it can be interpreted and used incorrectly and cause some very bad decisions.

 

[ngkjrs]

We need to consider 24hours for 365 days. this will reflect the management losses like planned holidays, lay-offs, weekly-offs (if utilized) - those hours are nothing but loss of opportunity to produce.

Here again, OEE is only a tool that highlights your losses. if you are keen on resolving all the loopholes in achieving the best, you should consider 24hours for 365 days.
Gopal

 

[harishjose]

For OEE measurement, i saw some sites use the planned work days as the total availiable run time (TART), e.g. 20 days a month (instead of 30/31 days a month), especially during the encominic recession period or a new facility. Is this correct (or say popular) for measuring the OEE??

Hi,

You are confusing Asset Utilization (AU) with OEE. Refer to any TPM text books. The time is the "planned time" by management. Asset Utilization on the other hand considers the total time as you mentioned.

Side note:The last E is for Effectiveness.

-Harish

 

[Citizen Kane]

Hi !


You should have a OEE calculation based on the number of worked days per year (so without public holidays, vacations, sundays, etc), not the available ones. But depends for ex. if you work or not on Saturday and/or Sunnday - this should be taken out.

In addition, you should add some depreciations - this will be more relevant in the case you are in PCB production - then the OEE will be more relevant related to the # of placed components.

There is here a discussion if the maintenance should be included in the calculation.

You will see that the CHOs, lack of material and/or poor qaulity material are the most trouble in the mass production.

 

[jasonb067]

I thought that OEE was simply

Availability x performance x quality

Where availability is (Operating time / planned production time)

performance is (Total pieces / Operating Time) / Ideal Run time)

quality is (good pieces / total pieces)

So I think the key is deciding what your actual planned production time is. If that is 24/7/365 I think that can be risky and poor planning (not sure, based on what you are making) but will work in the above description of OEE.

But if you are trying to get to the fact that you are loosing machine capacity to holiday etc. then I think you should use Assest Utilization not OEE.

Hope this helps. If not, hope you did not waste too much time reading it.

 

[bcod2000]

The OEE should be calculated related to 365 days/year and 24hour/day.In this way you will see in the OEE KPI a complex overview of your plant or operation : capacity usage, official holidays, plant shutdowns, lack of raw material ,absenteeism ,lack of orders etc. If you have expensive equipment then you should run it "NON-STOP".
However based on experience I saw that the OEE is calculated different in each company. In some plants you will not consider lack of materials for the OEE calculation, so your OEE will be higher. In this case you will have a good OEE KPI but your "expensive equipment" will not run. Other plants are not considering certain types of line stops(downtimes) for OEE calculations such as: maintenance, lack of materials, lack of orders, equipment updates...and the list can continue. This will get you a good OEE indicator.
If you decide to calculate the OEE as I first mention (365 days/year and 24hour/day) you will get at the beginning a lower OEE KPI. But in this case all "TEAM" (OEE is a must for the yearly target agreements) will have to focus to supply value for the company: get materials in time, solve the downtimes in less time, provide back-up plans for holidays...also you need to get additional customers to fill your entire capacity. This is the ideal case.

I hope this will help you.

Best regards.

 

[RosieA]

I'm no OEE expert, but I checked with our production manager, who is, and he commented as follows:

We are basing our TART on scheduled work hours.

It depends on how you want to use the data. If you are not machine capacity constrained and want to use it to measure how well you are performing and improving against planned work time the actual "schedule" fits. If you are machine capacity constrained and are trying to justify capital expenditures you need to measure OEE as a function of total time which includes all the time the machine is not manned.

Example below puts it in terms of reliability (scheduled production) vs. equipment utilization (24/7/365)

Percent of (scheduled production - reliability) or (calendar 24/7/365 - equipment utilization), that equipment is available for production.

https://www.downtimecentral.com/oee_teep.shtml

The new KPI that seems better suited to 24/7/365n is TEEP. See link above.

The pph goal in TEEP is usually defined as the maximum theoretical capacity in parts pph. No set-up, downtime and running at machine rate continually. In TEEP you usually calculate based on the 24/7/365 schedule.