Pull and Kanban拉动&看板

5
Nortel Confidential Information
7412 Part no.: Description: Slip rings
Box Type Box capacity
Issue No.
3/5 25 A
Lean Manufacturing
KanBan types
Transfer or Move or Withdrawal Kanban
l : averaged demand (parts per hours) a : security factor (covers for variations affecting Tw and Tp) C : # of parts per Kanban
PULL
KB
KB
KB
Produc tion Step
Produc tion Step
Produc tion Step
Custo mer
‘Supermarket’ : the location where a predetermined standard inventory is kept to supply downstream processes. As an item is removed from the supermarket, a signal to make more (e.g. : a KanBan card) is taken ny the material handler to the supplying process 4
Pull Kanban – Productas been pulled : the corresponding Kanban (= Production Instruction) is thrown in a Kanban Box (=Queue) 2. Regularly, a Production employee brings all Kanban from the FG Stockroom to the head of the line, and sort them by Product Type 3. Depending on the Product, a waiting time for accumulating the minimum number of Kanban
Inv.
Produc tion Step
Inv.
Custo mer
MRP / Forecast used for Long Lead Time items ordering,Tier 3 raw material and capacity Planning. Daily execution is triggered by actual pulls from downstream process and not by a production schedule
Prod. Instr. Transmission
Prod. Instr. Queue
Rule of Engagement
4. Once the Rule is fulfilled, waiting time for availability of installation
5. Manufacturing and delivery
Pattern Production Kanban will trigger production of a preset pattern of production (part A, then B, through J)
6
Nortel Confidential Information
Lean Manufacturing
Authorize conveyance of parts from a supermarket to a downstream process
Production or Make Kanban
Tells the upstream process the type and quantity of products to make. Signal Kanban will trigger production of a batch (because change over is needed) when a preset minimum number of containers is reached in the downstream process supermarket. It is usually a triangle shape sign. Material Kanban will trigger replenishment of material needed by the process
3
Nortel Confidential Information
Lean Manufacturing
Push vs. Pull
Order Mgt Order MRP Prod. Scheduling system Forecast Orders
PUSH
Produc tion Step
Inv.
Produc tion Step
Forecast – Plan Capacity, then Receive Order, Manufacture JIT & Pull Material
In a pull system materials are moved from one operation based on a request from the next operation.
Nortel Confidential Information
Queue for transport
Transport
Parts Retrieval Instr. Transmission
Supermarket M
Queue for Parts Retrieval Instr.
8
Lean Manufacturing
2
Nortel Confidential Information
Lean Manufacturing
Push vs. Pull
Forecast – Push Materials – Wait for Orders
In traditional (batch or push) manufacturing, materials are automatically moved from one operation to the next regardless if they are needed.
Lean Manufacturing
Just In Time (JIT)
1
Nortel Confidential Information
Lean Manufacturing
Pull
A system of cascading production and delivery instructions downstream to upstream activities in which nothing is produced by the upstream supplier until the downstream customer signals a need.
Lean Manufacturing
Pull Kanban – Transfer Loop
1. A lot (box) has been pulled by the customer : the corresponding Kanban (= Customer Parts Retrieval Instruction) is thrown in a Kanban Box (=Queue) 2. Regularly, a Supplier employee brings all Parts Retrieval Kanban from the Customer back to the FG of the Supplier 3. The Supplier picks a lot (box) according to his Customer Parts Retrieval Kanban , and replaces the Production Intruction Kanban. 4. The corresponding lot and its Delivery Kanban are shipped to the customer 5. The Production Instruction Kanban is used to trigger manufacturing
Availibility of Mfg Cell Production and Delivery to FG Stockroom, ready to be pulled by next process
Supermarket
M
7
Nortel Confidential Information
Transfer Loop
Part no.: 7412 Description: Slip rings Box capacity From : Machining M-2 Box Type Issue No. 25 A 3/5 To: Assembly A-4
Other means can be used to transmit production or delivery instruction : email, electronic signal (like EDI), empty container, Andon board, or any device that convey the needed information while preventing the introduction of erroneous instructions.
N : number of Kanban (i.e. cards or signs) to introduce in the loop Tw : waiting time for the Kanban to be accumulated and sent upstream (hours)
Tp : time for the good to be made / delivered from reception of Kanban to delivery (hours)
Nortel Confidential Information
Lean Manufacturing
Pull with KanBan
To establish pull, an information must be transmitted by downstream customer (whether within the same facility or in a separate one) to the upstream operation about what part or material is needed, the quantity needed and when and where it is needed. This information could be written on a sign or label or card : this is a Kanban.
Pull Kanban Loops
9
Nortel Confidential Information
Lean Manufacturing
Number of Kanban Cards in a loop
The number of Kanban in circulation is : Average Demand During Replenishment Lead Time + Safety Number of parts attached to the Kanban (Container Size) N = (Tw + Tp) (l + a) / C