Kanban

8 – 1Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

The Kanban SystemThe Kanban System

Receiving postKanban card for product 1

Kanban card for product 2

Fabrication cell

O1

O2

O3

O2

Storage area

Empty containers

Full containers

Assembly line 1

Assembly line 2

Figure 8.4 – Single-Card Kanban System

8 – 2Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

The Kanban SystemThe Kanban System

Storage area

Empty containers

Full containers

Receiving postKanban card for product 1

Kanban card for product 2

Fabrication cell

O1

O2

O3

O2

Assembly line 1

Assembly line 2

Figure 8.4 – Single-Card Kanban System

8 – 3Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

The Kanban SystemThe Kanban System

Storage area

Empty containers

Full containers

Receiving postKanban card for product 1

Kanban card for product 2

Fabrication cell

O1

O2

O3

O2

Assembly line 1

Assembly line 2

Figure 8.4 – Single-Card Kanban System

8 – 4Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

The Kanban SystemThe Kanban System

Storage area

Empty containers

Full containers

Receiving postKanban card for product 1

Kanban card for product 2

Fabrication cell

O1

O2

O3

O2

Assembly line 1

Assembly line 2

Figure 8.4 – Single-Card Kanban System

8 – 5Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

The Kanban SystemThe Kanban System

Storage area

Empty containers

Full containers

Receiving postKanban card for product 1

Kanban card for product 2

Fabrication cell

O1

O2

O3

O2

Assembly line 1

Assembly line 2

Figure 8.4 – Single-Card Kanban System

8 – 6Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

The Kanban SystemThe Kanban System

Storage area

Empty containers

Full containers

Receiving postKanban card for product 1

Kanban card for product 2

Fabrication cell

O1

O2

O3

O2

Assembly line 1

Assembly line 2

Figure 8.4 – Single-Card Kanban System

8 – 7Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

The Kanban SystemThe Kanban System

Storage area

Empty containers

Full containers

Receiving postKanban card for product 1

Kanban card for product 2

Fabrication cell

O1

O2

O3

O2

Assembly line 1

Assembly line 2

Figure 8.4 – Single-Card Kanban System

8 – 8Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

The Kanban SystemThe Kanban System

KA

NB

AN

Part N

um

ber:

1234567Z

Lo

cation

:A

isle 5B

in 47

Lo

t Qu

antity:

6

Su

pp

lier:W

S 83

Cu

stom

er:W

S 116

1. Each container must have a card

2. Assembly always withdraws from fabrication (pull system)

3. Containers cannot be moved without a kanban

4. Containers should contain the same number of parts

5. Only good parts are passed along

6. Production should not exceed authorization

8 – 9Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

Number of ContainersNumber of Containers

Two determinations

Number of units to be held by each container Determines lot size

Number of containers Estimate the average lead time needed to produce a

container of parts

Little’s law Average work-in-process inventory equals the average

demand rate multiplied by the average time a unit spends in the manufacturing process

8 – 10Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

Number of ContainersNumber of Containers

WIP = (average demand rate) (average time a container spends in the manufacturing process)+ safety stock

WIP = kc

kc = d (w + p )(1 + α)

k = d (w + p )(1 + α)

c

where k =number of containersd =expected daily demand for the partw =average waiting timep =average processing timec =number of units in each containerα =policy variable

8 – 11Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

Number of ContainersNumber of Containers

Formula for the number of containers

k =Average demand during lead time + Safety stock

Number of units per container

WIP = (average demand rate)(average time a container spends in the manufacturing process) + safety stock

8 – 12Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall.

Other Kanban SignalsOther Kanban Signals

Cards are not the only way to signal need

Container system

Containerless system