1. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Lean Systems Chapter 11

2. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Characteristics of Lean Systems Pull method of materials flow Pull method of materials flow Consistent quality Consistent quality Small lot sizes Small lot sizes Uniform workstation loads Uniform workstation loads Standardized components and work methods Standardized components and work methods Close supplier ties Close supplier ties Flexible workforce Flexible workforce Line flows Line flows Automation Automation Preventive maintenance Preventive maintenance

3. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Figure 11.1 Scrap Unreliable suppliers Capacity imbalance Continuous Improvement with Lean Systems

4. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Single-Card Kanban System Receiving post Kanban card for product 1 Kanban card for product 2 Figure 11.2 Fabrication cell O1O1O1O1 O2O2O2O2 O3O3O3O3 O2O2O2O2 Storage area Empty containers Full containers Assembly line 1 Assembly line 2

5. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Storage area Empty containers Full containers Single-Card Kanban System Receiving post Kanban card for product 1 Kanban card for product 2 Fabrication cell O1O1O1O1 O2O2O2O2 O3O3O3O3 O2O2O2O2 Assembly line 1 Assembly line 2 Figure 11.2

6. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Storage area Empty containers Full containers Single-Card Kanban System Receiving post Kanban card for product 1 Kanban card for product 2 Fabrication cell O1O1O1O1 O2O2O2O2 O3O3O3O3 O2O2O2O2 Assembly line 1 Assembly line 2 Figure 11.2

7. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Storage area Empty containers Full containers Single-Card Kanban System Receiving post Kanban card for product 1 Kanban card for product 2 Fabrication cell O1O1O1O1 O2O2O2O2 O3O3O3O3 O2O2O2O2 Assembly line 1 Assembly line 2 Figure 11.2

8. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Storage area Empty containers Full containers Single-Card Kanban System Receiving post Kanban card for product 1 Kanban card for product 2 Fabrication cell O1O1O1O1 O2O2O2O2 O3O3O3O3 O2O2O2O2 Assembly line 1 Assembly line 2 Figure 11.2

9. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Storage area Empty containers Full containers Single-Card Kanban System Receiving post Kanban card for product 1 Kanban card for product 2 Fabrication cell O1O1O1O1 O2O2O2O2 O3O3O3O3 O2O2O2O2 Assembly line 1 Assembly line 2 Figure 11.2

10. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Storage area Empty containers Full containers Single-Card Kanban System Receiving post Kanban card for product 1 Kanban card for product 2 Fabrication cell O1O1O1O1 O2O2O2O2 O3O3O3O3 O2O2O2O2 Assembly line 1 Assembly line 2 Figure 11.2

11. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Single-Card Kanban System KANBAN Part Number:1234567Z Location:Aisle 5 Bin 47 Lot Quantity:6 Supplier:WS 83 Customer:WS 116 Each container must have a card Each container must have a card Assembly always withdraws from fabrication (pull system) Assembly always withdraws from fabrication (pull system) Containers cannot be moved without a kanban Containers cannot be moved without a kanban Containers should contain the same number of parts Containers should contain the same number of parts Only good parts are passed along Only good parts are passed along Production should not exceed authorization Production should not exceed authorization

12. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Number of Containers k = d( w + p )( 1 + ) c d = 2000 units/day p = 0.02 day = 0.10 w = 0.08 day c = 22 units Westerville Auto Parts Example 11.1

13. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Number of Containers k = 2000( 0.08 + 0.02 )( 1 + 0.10 ) 22 d = 2000 units/day p = 0.02 day = 0.10 w = 0.08 day c = 22 units Westerville Auto Parts Example 11.1

14. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Number of Containers k = 2000( 0.08 + 0.02 )( 1 + 0.10 ) 22 d = 2000 units/day p = 0.02 day = 0.10 w = 0.08 day c = 22 units Westerville Auto Parts Example 11.1

15. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Number of Containers k = 10 containers d = 2000 units/day p = 0.02 day = 0.10 w = 0.08 day c = 22 units Westerville Auto Parts Example 11.1

16. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Number of Containers d = 2000 units/day p = 0.02 day = 0.10 w = 0.06 day c = 22 units Westerville Auto Parts k = d( w + p )( 1 + ) c k = 10 containers Example 11.1

17. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Number of Containers d = 2000 units/day p = 0.02 day = 0.10 w = 0.06 day c = 22 units Westerville Auto Parts k = 2000(0.06 + 0.02)(1.10) 22 k = 10 containers Example 11.1

18. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Number of Containers d = 2000 units/day p = 0.02 day = 0.10 w = 0.06 day c = 22 units Westerville Auto Parts k = 2000(0.06 + 0.02)(1.10) 22 k = 10 containers Example 11.1

19. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Number of Containers d = 2000 units/day p = 0.02 day = 0.10 w = 0.06 day c = 22 units Westerville Auto Parts k = 8 containers k = 10 containers Example 11.1

20. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Number of Containers Westerville Auto Parts d = 2000 units/day p = 0.02 day = 0.10 0.06 w = 0.06 day c = 22 units k = 8 containers k = 10 containers Figure 11.3

21. To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Operational Benefits Reduce space requirements Reduce space requirements Reduce inventory investment Reduce inventory investment Reduce lead times Reduce lead times Increase labor productivity Increase labor productivity Increase equipment utilization Increase equipment utilization Reduce paperwork and simplify planning systems Reduce paperwork and simplify planning systems Valid priorities for scheduling Valid priorities for scheduling Workforce participation Workforce participation Increase service/product quality Increase service/product quality