chapter 9 inventory kanbans automating the replenishment cycle
TRANSCRIPT
Chapter 9
Inventory Kanbans
Automating the Replenishment Cycle
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Kanban
• A Japanese word that means signboard or signal.
• Are signals developed to automate the inventory replenishment cycle for items used repetitively in a facility
• Communicate the need for additional material to be pulled from the supplier
• Integral in a “pull” manufacturing system.
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Typical Kanban Signal
• An empty container designed to hold a standard quantity of material or parts.
• The container is sent back to the supplier from the customer when empty.
• If returnable containers are not used, a kanban can be as simple as a laminated card.
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Kanbans
• Are:– Communication devices from the point of use
to the previous operation.– Purchase orders for your suppliers.– Work orders for your manufacturing area.– Visual communication tools.– Paperwork eliminators.
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Kanbans
• Are not appropriate for:– Single piece or lot production– Safety stock– Systems which push inventory carrying
requirements and the associated carrying costs back to the supplier.
– Long range planning tools.
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Kanbans Reduce Waste
• Eliminate – Over-production– The need for a stockroom– The need to reissue purchase orders
• Reduce:– The data management task for prod plng, work orders– Inventory– Parts expediting– Parts shortages– Material handling
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Types of Kanbans (Pull Signals)
• Cards attached to portable containers such as tote pans
• Supplier replaceable cards on cardboard boxes designed to hold a standard quantity
• A painted spot or border on the floor around the standardized container
• Color coded striped golf balls• E-mails• Bar code labels• Variations of above
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Summary
• Kanbans tie related processes together as if they were connected by an invisible conveyor. Kanbans:– Improve communication– Improve customer satisfaction– Reduce inventories– Reduce waste
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Pull Systems
Outcomes
• Define Pull system
• Define supermarket
• Define kanban
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Production Scheduling
• Constantly change
• Production never produces to a schedule
• Utilize MRP (Material Resource Planning)
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Supermarket Pull
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Scheduling
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Small-Lot Production + Leveling
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Leveling Work Volume
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Leveling Work Volume
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Flow
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The Problem with Inventory
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Kanban TypesProduction Kanban• “One-per-customer” kanban• Supplying process can produce
as little as one containerSignal (Triangle) kanban• “One-per-batch” kanban• Signals when a reorder point is
reached and another batch needs to be produced
• Used in supplying process where changeovers are required
Withdrawal kanban• “Shopping list” kanban• Instructs the material handler
to get and transfer parts
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The Six Steps of Kanban
1. Consumption process withdraws only what is needed2. Produce to replenish only what is withdrawn by the next
process3. Do not send defective products to the next process4. Parts must not produced and conveyed when there is
no kanban5. Kanban must be attached to the actual parts or
container6. The actual number of parts in the container must match
the number on the kanban
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One Piece Flow
Goal• Represents a special case of kanban• Lot size/quantity is oneBenefits• Minimizes waste in the process• Defects affect only one component thus creating highest
possible quality• Minimizes inventory and space requirements• Keeps pace with customer demand• Efficiently utilizes labor in a balanced process• Best possible throughput in a balanced process
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Signal Kanban System
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Summary
• Pull Systems– Single scheduling point– Produce to replenish use– Customer demand creates production
• Level loading
• Kanban