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    We are in the process of redesigning our supply chain to decrease material outages.  I suggested we start using KanBans to drive demand INSTEAD of our traditional MRP system.  I have gotten feedback from several people saying that they already tryed the “KanBan” or “JIT” system without success.  However, when I investigate their processes I find that there was never a VISUAL cue used in the “KanBan” system.  The “KanBan” process always boiled down to trying to work WITH the existing structure of the MRP system and removed operator control.
    My question is: 
    Do successful KanBan implementations require VISUAL signals and empowerment by material handlers/assembly workers to drive demand?



    I have spent the past 10 years using the Kanban system and feel it works well for us.  The bottom line is it will reduce invetory however it takes some communication and monitoring to be effective.  If that does not scare you then you should be good to go.  You may want to start out being conservative with Kanban quantity until you get the system dialed in.  This will reduce the risk of of shortages during the learning curve.  Here is the basics behind our Kanban system.  We have a visual Kanban board with velco stuck Knaban cards.  The three key people with input to this Knaban board are the material handler the assemblers and the material buyers. 
    The material buyer sets up the kanban size (Size of Tote) based on at least a four hours production before the material handler will need to replentish the cell.   He sets up the Kanban qty (Amount of Totes) based on usage and material lead time.  The buyer must keep track of the Kanban board.  When a part recieves the predetermined amount of Kanban cards in the used section the buyer must reorder. 
    The material handler- delivers full totes to the point of use and returns Kanban card to the Kanban board and velcros it to the used section.
    Assembler – They use the parts and when they get close to needing replentished the turn on a red siren light to get the material handler’s attention. 
    I am an Engineer not a materials expert however, I hope I was some help?


    James A

    In a previous professional existence, when I set up and ran a Kanban system, we only used tokens at the machining operations – these were arranged in columns (according to part and op number) on boards.  As each box of parts was completed, the token was removed from the board and placed in the box with the components.
    As each machine was running around four parts for the same product, it was impossible to ’empty’ all four columns simultaneously – so as demand pulled on the machined components, tokens were removed and placed back in the relevant holder – eventually the stack reached a “re-order” point (based on safe shop stock levels) and that determined the next change-over after the job that was running.
    In this way, we placed control essentially in the hands of the assembly area, and the ‘pull’ worked back into production from there – the materials people didn’t really have any input.  It was only the assembly and machining areas that had control.
    Visual signals were used, as I said earlier, on the machines themselves, and in the window of the assembly area to call for more (specific) parts.
    Because of the general racket and noise we didn’t use sirens or flashing lights – only boards and signs.
    One thing to be aware of though, the Kanban system will rapidly highlight any production or part problems – in a way this is good, because you can then fix them, but if the company was previously of a ‘batch’ mentality (when the problems could be effectively hidden) then it’s a great excuse to declare that Kanban or JIT doesn’t work.
    That can be an unpleasant experience if you’re not prepared!!
    James A



    Yes!  Without a visual factory you really haven’t implemented a lean manufacturing system. I believe it is important to recognize the a kanban system is only one small piece of a “Lean” plant operation.
    As in any other improvement implementation you must review the entire systerm (Value Stream Mapping) and review the flow of the entire system including lead times from suppliers, placing orders, receiving inspection etc.



    I’ve seen Kanban fail in a section of my plant because the process wasn’t enforced. Mins and Max levels allowed by the card system weren’t followed hence to much of some material and not enough of others.  Its a change in operator SOPs (standard operating proceedure) they been trained make product at one level and now you want to change the way they been doing things for years. 
    Lots of good feedback in this thread so far, but my piece of advice is to train, train, and train when you’re ready to launch then pay close attentions to the deatils when you do launch.



    I have been installing Kan Ban’s for 15 years. When they go well they do so because:
    1) We involved the line and Material Handeling employees in the process so they were not threatened by it.
    2) We monitored very closely the cards for the first three or four weeks, It is amazing how these come up “missing” when you know you have an employee or two who does not like the system.
    3) We made sure the entire supply chain was made aware of our shift. That is to say our supply base needed to have ample replenishment stock on hand.
    4) Initially, for some larger applications, we raised our inventory level to give the process time to work on the shop floor very well, then focused on the rest of the supply chain in back of the plant.
    5) TOP MANAGEMENT MUST BUY IN, and understand the mechanics of the process. When they are asked why they want this by the shop floor employees they must know about the pitfalls and beniftis so they can reenforce the need for the program amongst all employees.
    Hope this helps.



    This is an asnwer to your question. Yes you need visuals and by material handlers/assembly workers.  Visuals are the key.

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