合同セミナー『サプライチェーンリスク管理ど人道支援ロジスティクス...

合同セミナー『サプライチェーンリスク管理ど人道支援ロジスティクス』

Tokyo Maritime University 07/04/2013

Optimization of the configuration of a supply chain and impact of a

supplier disruptionProf. Matsukawa , MARC Seiji

Keio University, Graduate School of Science and Technology

2

Introduction

3

How to configure a supply chain? What suppliers, processes, transportation modes

to choose?

Indeed each stage of a supply chain might have several options

High cost Low costShort lead time Long lead time

Prof. Matsukawa, MARC Seiji

Introduction

4

Graves and Willems (2005) explore the supply chain configuration issue

Minimization of the supply chain cost with a dynamic program

Goal of this research: Compare single and dual sourcing Analyze the effects of a supplier disruption Adapt the model to take into account fixed

ordering costs

MARC SeijiProf. Matsukawa, MARC Seiji

Table

5

1. Supply chain configuration model2. Single and dual sourcing3. Impact of a disruption4. Inventory policies

5. Conclusion


Supply chain configuration model

6 MARC SeijiProf. Matsukawa, MARC Seiji

Network model and inputs

7

Network model of the supply chain

Several options at each node:

5

4

3

2

1 6

7

8

9

112

3

Cost

Lead time

External demand:• Mean• Standard deviation


The optimization problem

8

We try to minimize the total SC cost:

Subject to some constraints: One option chosen at each node Feasibility of the service times Respect of the service time to the external customer

Safety stock cost

Pipeline stock cost COGS


The dynamic program

9

The variables: options and service times At each step of the program we evaluate the

following functional equation:

Output of the program: Best options at each node to minimize the total SC

cost Optimal service times at each node


Safety stock cost Pipeline stock cost COGS

Local VS global optimum

10

Local best option option that minimizes the cost at the stage

Global best option option that minimizes the total SC cost

We compare the expected total SC costs With the local optimums: 56 482 $ With the global optimums: 54 915 $

node 1 2 3 4 5 6 7 8 9Local option 3 2 2 3 1 3 5 1 5Global option

1 5 2 3 1 3 5 1 5


Single and dual sourcing


Differences between single and dual sourcing

Single sourcing Dual sourcing

12

Better pricing

Better and longer relationship

Better communication

Better security

Better flexibility

Maintain competition between suppliers80% 20%


Selection of the second supplier

13

First selection policy: Simplest selection policy

Better implementation in the existing program

First run Second run


Selection of the second supplier

14

Second selection policy

Better selection policy

The existing program has to be adapted

First run


Single VS dual sourcing

15

We compare the expected total SC cost Single sourcing: 53 171 $ Dual sourcing: 57 404 $

node 1 2 3 4 5 6 7 8 9First option 1 5 2 3 1 3 5 1 5Second option

2 2 1 2 2 1 2 2 2


Impact of a disruption


The calculation program

17

The calculation program simulates the behavior of the SC over a certain period of time (ex: 20 weeks)

Configuration program

Calculation program

Demand realization

Disruption characteristics:• Impacted supplier• Starting time and

duration• Cost• Revenue• Profit

For example:• Best option of stage 8• Starts at t=3 for 4

periods

node 1 2 3 4 5 6 7 8 9best option 1 5 2 3 1 3 5 1 5second best option 2 2 1 2 2 1 2 2 2

0 1 2 3 4 5 6 7 8 9 1011121314151617181920708090

100110120130

real demand


Cost calculation

18

The safety stock cost:

The pipeline stock cost:

The cost of goods sold:


Cost calculation

19

Penalty cost: Recovery cost

Cost of increasing the production

capacity

Cost of holding some inventory + cost of inactivity

Cost of holding some inventory + cost of inactivity

Medium penalty rate

High penalty rate

single sourcing

dual sourcing

penalty rate

disrupted node 200 200other nodes 50 20 MARC SeijiProf. Matsukawa, MARC Seiji

Profit calculation

20

The profit at time t is:

630 $


Single VS dual sourcing without disruption

21

Cost

0 1 2 3 4 5 6 7 8 9 101112131415161718192045000470004900051000530005500057000590006100063000

single sourcingdual sourcing

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20708090

100110120130

real demand

real demand

Total SC cost over the 20 weeks: Single sourcing: 1 113 410$ Dual sourcing: 1 202 583$ Difference: 8%



22

Profit

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

-5000

0

5000

10000

15000

20000


Total SC profit: Single sourcing: 207 699$ Dual sourcing: 118 526$ Difference: -43%


Single VS dual sourcing with disruption

23

Total SC profit: Single sourcing: -99 109$ (207 699 $) Dual sourcing: 104 214$ (118 526 $)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

-50000

-40000

-30000

-20000

-10000

0

10000

20000

30000


(No disruption)


disruption

time

Single sourcing analysis

24

Cost

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2030000

35000

40000

45000

50000

55000

60000

without disruptionwith disruption

Disruption time Lead time of the disrupted node

Service time of the disrupted node

Penalty cost


Single sourcing analysis

25

Profit Without disruption: 207 699$ With disruption: -99 109$

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

-50000

-40000

-30000

-20000

-10000

0

10000

20000

30000


Disruption time Lead time of the disrupted node

Service time of the disrupted node

Profit overshoot


Dual sourcing analysis

26

Cost

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2020000250003000035000400004500050000550006000065000


Only 20% of supply

Back to 100%

Impact of the stocks of 2nd option

Disruption time

Lead time of the disrupted node


Dual sourcing analysis

27

Total SC profit: Without disruption: 118 526$ With disruption: 104 214$ Difference: 12%

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

-15000

-10000

-5000

0

5000

10000

15000

20000

25000


Only 20% of supply

Back to 100%


Inventory policy


The inventory policy

29

In the existing model, (s,S) policy with no fixed ordering cost S = s Orders at each period of time

We change the inventory policy K ≠ 0 We choose an (s,Q) policy

We work with the single sourcing policy on the expected costs


The (s,Q) policy

30

The inventory level:

s

t

I


Reorder quantity Q = EOQ

Results with fixed ordering costOrders at each period (s,Q) policy

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Expected total cost: (53 171 $) 120 171 $ Inventory cost:

3901 $ 3% Pipeline + COGS:

49 270 $ 41%

Fixed ordering cost:67 000 $

56%

Expected total cost:105 504 $

Inventory cost:33 292 $

31% Pipeline + COGS:

49 270 $ 47%

Fixed ordering cost:22 942 $

22%


Conclusion


Conclusion

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Single VS dual sourcing: Single sourcing more efficient if no disruption In case of disruption, dual sourcing is way better

With fixed ordering cost: (s,Q) ordering policy has better results than every

period ordering policy The balance of the different types of cost is

different


Conclusion

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This research produced: A configuration tool that works with different

sourcing and inventory policies A quantitative analysis of different types of SC

configuration A comparison between the different types of SC

configuration


Further research developments

35

Improve the risk management approach: Take into account a disruption risk

Improve the model to optimize more general SC


References

36

Optimizing the supply chain configuration for new productsS.C.Graves, S.P.Willems, Management Science, 2005

Optimal supply chain configuration strategies for new productsS.P.Willems, PhD thesis, MIT, 1999

Managing risks of supply chains disruptions: dual sourcing as a real optionS.Pochard, master thesis, MIT, 2000

Trial by fire: a blaze in Albuquerque sets off major crisis for cellphone giantsA.Latour, Wall Street Journal, 29 Jan 2001

To the rescue: Toyota’s fast rebound after fire at supplier shows why it is toughV.Reitman, Wall Street Journal, 08 May 1997

The power of flexibility for mitigating supply chain risksC.Tang, B.Tomlin, International Journal of Production Economics, 2008

Single or dual sourcing: decision-making in the presence of supply chain disruption risksH.Yu, A.Z.Zeng, L.Zhao, Omega, 2009

Competition in multiechelon assembly supply chainsS.M.Carr, U.S.Karmarkar, Management Science, 2005


Thank you for your attention

37

Question or remark ?


Inventory policy

38

Cycle times

1 2 3 4 5 6 7 8 90.0

1.0

2.0

3.0

4.0

5.0

6.0

0

100

200

300

400

500

600

cycle timeratio K/C



MARC Seiji39

Cost

0 1 2 3 4 5 6 7 8 9 101112131415161718192045000470004900051000530005500057000590006100063000


0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20708090

100110120130

real demand

real demand


合同セミナー 『 サプライチェーンリスク管理ど人道支援ロジスティクス...

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合同セミナー『サプライチェーンリスク管理ど人道支援ロジスティクス...