OEE (Overall Equipment Effectiveness) Downtimes Calculation

[michu]

Hello,

We've monitored OEE for one year. The most common problem we experienced is fact that the operators artificialy increse downtimes time in order to improve performance ratio.

I'd like mention two things:
Performance index has a big innfluence on its monthly salary
Operators calculates downtimes itself

Have you got any ideas how to change this sistuation

 

[Stijloor]

Re: OEE downtimes calculation

Hello,

We've monitored OEE for one year. The most common problem we experienced is fact that the operators artificialy increse downtimes time in order to improve performance ratio.

I'd like mention two things:
Performance index has a big innfluence on its monthly salary
Operators calculates downtimes itself

Have you got any ideas how to change this sistuation

Hello Michu,

There are ways to automate the data collection.

Here is a link to a company that provides such a system.
(NOTE: I am not associated with this company)

Aside from this, it seems that you have a operator-management issue here. Has this process been subject to internal audits? Not knowing all the specifics, this is obviously a serious problem.

Are these OEE scores used in a punishment/reward-type system? Because whatever it takes, operators will make sure that the numbers come out right. Is it possible that the OEE scores are impacted by process issues over which the operators have no control?

Just some questions for consideration.

Stijloor.

 

[anrice]

Hi Michu,

I've worked with OEE for many years and would need more information to try and help you. It can be resolved using different means and will depend on how you collect the current information. Ability to tie in with automation is also an option.

How do you currently calculate OEE? Do you collect information by Shift? What are you measuring? Even though you know that they are over reporting downtime do you know what downtime they are over-reporting?

If you record downtime by shift then displaying a trend analysis of say unplanned downtime should display a discrepancy across the shifts whereas the downtime reasons on a trend across shifts should even itself out.

Also if they are overreporting are you seeing speed gains (i.e. Performance > 100%?).

If you can provide more information I may be able to give further assistance.

 

[ngkjrs]

OEE is the cumulative product of Availability Rate, Performance rate and Quality Rate.

Irrespective of your downtime, OEE can vary only if the accepted production lot (count) varies. If the downtime goes down, performance increases. From your mail it makes clear that you have two separate teams for production and maintenance.

Club them together. Those who produce will be responsible for the functioning of the equipment and the quality of the product. Get rid of "you make i fix" syndrome.

Then such issues can be resolved.

 

[alokb]

Dear Sir,

First of all let us understand why OEE is calculated?

Answer to this question ,as far as my understanding goes, is.

To improve

1. Availability
2. Performance /speed
3. Quality output

Basic idea it is not only maintenance that is responsible for production / productivity ,there is something else which is needed to be looked for improvement.
It appears that your system is again falling into the trap of blaming maintenance.

If your performance factor is 100 % why calculate OEE than.
Go back to calculate Availability only and let maintenance department take all the responsibility.

Thanks.

Alok

 

[ngkjrs]

OEE is calculated to identify where the loss had occured. whether in time, speed or quality.

So, one needs the right input so that the corrective actions are rightly planned and impelemented.

 

[swapnilmarne]

Hello,

You can split the downtime into different types as :
1) Quality
2) Power off
3) Setting
4) Shortage
5) No Operator
6) Maintenance
7) Others ( Has To specify the reason)

So that operator can not put downtime blindly as the above data represents particular department's contribution in downtime .
You can also form same analysis like average setting time, Inspection time according to depts.
This will help you to share the OEE load within the organisation not only upto you.

Regards

Swapnil

 

[AggieRob02]

Would OEE Be ever Calculated into you established Takt Time? Just a thought....

 

[Eric ng]

I had the similar problem when I first introduced OEE for the equipment maintenance group in a Electronic product manufacturing plant. All the maintenance personnel including the section head and manager in charge were trained in the methodology. The section head has the responsibility to ensure that all the key parameters are properly defined, and a baseline OEE for each individual equipment was defined and documented, especially downtime. A year later, the section head left the company, and the company experienced throughput problem, so the manager in charge changed the definition of downtime to make it looks good, and tried to shift the problem to quality or engineering. This was discovered during one of the monthly performance review presentation which prompted me to audit the method of OEE calculation.
In short, data integrity must be maintained at all times and that depends on the integrity of the person in charge of the operation.


Eric Ng