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LEAN Machine Uptime

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  • #39834

    VoteForPedro
    Member

    How is machine uptime for a LEAN capacity analysiss calculated?  Are external events that prevent production such as stock-outs, etc.  included? Thanks.

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    #122191

    WestCoaster
    Member

    Uptime for Lean capacity (or OEE – Overall Equipment Efficiency) should include all events (productive and non-productive) but the scheduled stops (like time for preventive maintenance, trials for new products, machine modifications). In other words everything but the time you schedule in adavance to be “not productive” – even if you are producing pieces like in trials for new products, in this case you should not consider the productive time for the produced pieces.
    Regards

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    #122223

    billybob
    Participant

    Hello folks,
    If your OEE system is robust enough you can track OEE details to include planned stops for PMs, training, sample builds, and so on.  Its only a matter of adding a couple of more blocks onto the sheet. But you can still not calculate this time as part of OEE which is the norm.
    In a strict OEE environment plan stops may be considered in-house vacation for operators.  100% OEE tracking will help to check / see PMs take the same time for the same tasks and will give the operators a feeling that since all time is being tracked that all time is important. Isn’t it?
     In tracking prototype builds you can see where your loses are at the begining of the process and how much scrap you generate, how long it took to do the set up and what is the real cycletime at that level.  
    What you begin to realize up front will only make the transition to series production that much easier. 
    Later,
    Billybob

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    #122229

    VoteForPedro
    Member

    So in a simple capacity analysis for a given work station:
    Machine Uptime (Available Work Time/Cycle Time) I would calculate Uptime by:
    Time machine is Available to work (excluding PM, etc)  /  Time machine actually worked (including any and all delays not related to planned downtime).  Is this valid?  Thanks!

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    #122231

    VoteForPedro
    Member

    So if the machine is ready and fully capable, but can not operate as a result of some additional delay (i.e. stock out, etc), this lack of activity is still attributed to the Uptime or OEE meaurement? Thanks once again.

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    #122233

    Paul Gibbons
    Participant

    Hi Pedro,
    From my experience it depends on your scope and what you are trying to achieve. The OEE can either be used to focus at a micro level on a particular piece of plant, recording inefficencies directly related to the process/output; or, it can be used at a more macro level recording inefficiencies at the input/process/output stages.
    I always try and capture as much data as possible to understand the what I call the 3 levels of OEE.
    1, Micro plant specific
    2, Macro process specific
    3, Plant utilisation (useful for capacity planning and future investment).
    This is just my opinion based on manufacturing processes.
    Paul

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    #122234

    WestCoaster
    Member

    VoteForPedro,
    The convention that I gave you  (excluding the scheduled stops) is very common and widelhy used. it makes easy to integrate the uptime with the “traditional” OEE calculation. Think about that. If you need 12 hours of “preventive maintenance” to make 12 hours of working machine, excluding the preventive maintenance will give you a 100% OEE, when should really be 50%…I saw folks not making any differencial of scheduled stop or not. Both conventions make sense to me depending of the amount of scheduling time Vs the available time. If scheduling time is in average around 5-7% or less, I will say not to include them on the uptime/OEE calculaion. My company’s rules exclude the scheduled stops from the normal problems (we are around 3% PM). In that way we do not mess regular losses from organizational losses and the view of the real daily problems is more evident. Everything should be based in how serious you are in declaring your problems. E.g. not tending to “mask” problems calling them “scheduled stop” but being in reality a corrective maintenance intervention done when the problem occurred….
    Uptime / cycle time is the OEE

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    #122235

    billybob
    Participant

    Hello folks,
    Typically, if a machine is ready to run and there is no stock (or no operator)  it is still calulated in the uptime portion of OEE.  Its how you illustrate the problem of no material. 
    A low OEE is always a good attention getter..especially when you can point the problem to the materials group. 
    Later,
    Billybob
     

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    #122236

    WestCoaster
    Member

    In time, check this article. It has pretty good points about OEE and uptime:
    http://www.plantservices.com/articles/2003/85.html

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    #122248

    VoteForPedro
    Member

    Good article…answers many questions…Thanks to everyone for your collective help!

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    #122252

    BTDT
    Participant

    The forum must have brought the site down. I can’t get to the site at all.BTDT

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