PERMODELAN RANTAI PASOK DUA ESELON

DENGAN MEMPERTIMBANGKAN DISKON BIAYA TRANSPORTASI DAN

KELAYAKAN KONSOLIDASI

TESIS

Abdul Muid 2507203006

DOSEN PEMBIMBING Dr. Eng. Ir. Ahmad Rusdiansyah, M. Eng.

Nani Kurniati, ST., MT

2

Ruang Lingkup Penelitan

Gudang

(Cross-dock

Pengecer

Pengecer

Pengecer

Pengecer

TL (Truck Load)

TL with consolidation

or

LTL

carrier

Pabrik

Pengecer

3

Ruang Lingkup Penelitan

Gudang(Cross-dock

Pengecer Pengecer Pengecer Pengecer

TL (Truck Load)

LTL (Less than Truck Load)

Pabrik

Ruang lingkup penelitian Hill dan Galbreth (2008)

4

Ruang Lingkup Penelitan

Pabrik

Ruang lingkup penelitian Attanasio dkk. (2007)

PabrikPabrik

5

LATAR BELAKANG

Manajemenrantai pasok

sebagai strategibaru dalampersainganusaha

Perlunyapendekatanyang tepatterhadapbiaya

transportasi

Faktorkonsolidasi

sebagai suatustrategi untukmeminimasi

biayatransportasi

Penelitian

6

PERMASALAHAN

Bagaimanamembuat model rantai pasok duaeselon yang

mempertimbangkan biaya diskondan konsolidasipengiriman kepara pengecer

Bagaimanapengaruhkelayakankonsolidasiterhadap

rantai pasok

Faktor – faktor apayang berpengaruhterhadap biayarantai pasok duaeselon yang

mempertimbangkanbiaya diskon dan

konsolidasipengiriman ke para

pengecer

Penelitian

7

TUJUAN

Membuat model model rantai

pasok dua eselonyang

mempertimbangkan biaya diskondan konsolidasipengiriman kepara pengecer

Mengetahuipengaruhkonsolidasiterhadap

biaya rantaipasok

Mengetahui faktor –faktor yang berpengaruh

terhadap rantai pasokdua eselon yang

mempertimbangkanbiaya diskon

Penelitian

8

BATASAN

Perencananhanya

dilakukansekali padaawal periodeselama periodeperencanaan

Biayapemesananke shipper

tidakdimasukkandalam model

Penelitian

Biayacrossdocktidak di-

pertimbangkan

Pengecerberadadalamsatu

area tarif

9

STATE OF THE ART OF THE RESEARCH

Biaya transportasi dimodelkansebagai fungsi linier

(Ng dkk., 2001 dan LeBlancdkk.,2004)

Biaya transportasi diasumsikanbersifat tetap (fixed cost) dandimasukkan menjadi bagiandari biaya pesan (order cost)

(Leenders dkk., 2002)

Penyimpangan asumsi linier dankonstan terhadap biaya

transportasi khususnya padaless than truckload (LTL)

(Carter dan Ferrin, 1996, Bohman, 2006)

Model Rantai Pasok yang mengakomodasi biaya transportasi LTL dengan fungsi biaya diskon pada semuaunit / all-unit discount cost structure

(Carter dkk., 1995; Carter and Ferrin, 1996; Chan dkk., 2002; dan Croxton

dkk., 2003)

Heuristik Rantai Pasok GudangTunggal – Multi Retailer

dengan all-unit transportation cost discount structure

(James Hill, J.dan Galbreth, M., 2008)

PermodelanRantai PasokDua Eselondengan

Mempertimbangkan Diskon

BiayaTransportasidan KelayakanKonsolidasi

Usulan Thesis

Problem integrasi pengepakan dan pengiriman

(Attanasio dkk, 2007)

Penelitian Terdahulu

10

RESEARCH GAP

√−√Simplifikasi model

MAUD−MAUDPendekatan Model

MILPILPMILPModel yang digunakan

Model

√√√Biaya transportasi

Variabel Biaya Pengirim

√−√Biaya simpan

Variabel Biaya Pengecer

All Discount−All DiscountKebijakan Diskon

Volume Pengiriman−Volume PengirimanPertimbangan nilai diskon

√√−Konsolidasi pengiriman

√√√Volume pengiriman

Variabel Keputusan

√−√Biaya inventori pengecer

√√√Biaya pengrirman

Ukuran Performansi

√√−Konsolidasi pengiriman

√−√Diskon Biaya pengiriman

Kebijakan Sistem

√√√Pengecer / tujuan

√−√Gudang (Cross dock)

√√√Pabrik asal

DuaSatuDuaTingkatan rantai pasok

Ruang Lingkup

Ususlan ThesisAttanasio dkk

(2007)Hill dan Galbreth

(2008)Karakteristik Penelitian

11

All Units Quantity Discounts Structure

( )

≤<≤<≤<<

=

=

+

,

,

,

,0

,00

1

211

1

QyjikaQ

yQyjikaQ

yQyjikaQ

yQjikac

Qjika

QG

nn

iii

ααα

12

Model MILP (1)

∑∑∑∈

+β+βRr j

rjrj

j YHMin

( )∑∑ ∑ ∑∑∑

−+++≥x j jk a

jkxagenapa

xajkxaganjila

xajxa hjkDSDSF

∑ ∑∑∑∑≤ ≤

∀=+kj

kxkj a

jkxar b

jkrxb xkmDD .,,

∑ ∑∑∑∑∑∑ ∀+=≥≥x jk x a

jkxar jk b

jkrxbj jDDR .,

13

Model MILP (2)

.jVR j ∀≤

.jPHR jj ∀≤

( ) ∑≥

− ∀≤≤jk

jxaxajkxajxaax xajFCDFC .,,1

{ } ,,...2,1,0 jH j ∀∈{ },1,0∈jkrxbX

{ },....3,1,0∈rjY

14

Model MILP (3)

{ } ,,,1,0 axjF jxa ∀∈

∑ ∀≤a

jxa xjF .,1

{ } XxSa

xa ∈∈∑ ,1,0

15

Model MILP yang disederhanakan (1)

∑∑∑∈

+β+βRr j

rjrj

j YHMin

∑ ∑∑∑∑≤ ≤

∀=+kj

kxkj a

jkxar b

jkrxb xkmDD .,,

( ){ }∑∑ ∑

−++

≥x j jkjkxxjkxxjx hjkDSDLF

∑ ∑∑∑∑∑ ∀+=≥≥x jk x

jkxr jk b

jkrxbj jDDR .,

.jVR j ∀≤.jPHR jj ∀≤

∑≥

∀≤jk

jxjkx xajCFD .,,

16

Model MILP yang disederhanakan (2)

{ } ,,...2,1,0 jH j ∀∈

{ },1,0∈jkrxbX

{ },....3,1,0∈rjY

{ } ,b,x,j1,0Fjxb ∀∈

17

Analisa Perilaku Model Rantai Pasok

Perubahan kapasitas konsolidasiTipe 2

Perubahan tarif LTL carrierTipe 3

Perubahan biaya simpanTipe 4

Pilihan alternatif LTL carrier atau truckloadTipe 5

Contoh NumerikTipe 1

KeteranganSkenario

18

Contoh Numerik (1)

703.38

15.44233 July212 JuneMarseille8

61.54616 June111 JuneMarseille7

35.23616 June111 JuneMarseille6

19.59616 June111 JuneMarseille5

19.05616 June111 JuneMarseille4

102.54616 June212 JuneAncona3

207.34515 June111 JuneMarseille2

242.65515 June212 JuneAncona1

Weight(mkxb)

PeriodeDeadlin

e(k)

Deadline

PeriodeRelease

Time

Release time

Customer

location

Order(b)

19

Contoh Numerik (3)

1,328Bari – Ancona – Marseille3

1,280Bari – Marseille2

640Bari – Ancona1

Fixed Cost (USD)(ββββr)

KeteranganRute (r)

20

Daftar tarif dalam satu zone

200

195

190

185

180

175

170

165

160

155

150

145

140

135

130

125

120

115

110

105

100

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

15

10

5

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0

17.1 25.0 33.1 41.0 49.1 61.5 71.8 85.6 98.3 103.7 106.7 109.7 113.1 115.5 118.7 123.1 125.1 128.4 131.3 136.0 142.8 149.6 151.3 152.5 153.3 156.5 159.6 162.3 164.9 167.3 169.4 171.3 172.9 174.4 175.6 176.6 181.5 186.4 191.3 196.2

21

Struktur biaya rantai pasok

TL1COST TL2COST HOLDTL2COST LTLCOST HOLDLTLCOST

8,000.00

1,920.00

453.85 591.46202.65

22

Prosentase struktur biaya rantai pasok

TL1COST72%

TL2COST17%

HOLDTL2COST4%

LTLCOST5%

HOLDLTLCOST2%

23

Rute dan skedul pengiriman

24

Kapasitas TL2 naik / turun 10%

3.167,96

2.675,77

3.198,31

2.400,00

2.500,002.600,00

2.700,00

2.800,002.900,00

3.000,00

3.100,003.200,00

Skenario awal Kap TL2 naik 10% Kap TL2 turun10%

Total biaya Outbound

25

Kapasitas TL2 naik / turun 10%

0,1554

0,0096

-

0,0200

0,0400

0,0600

0,0800

0,1000

0,1200

0,1400

0,1600

Penurunan total biayaoutbound karena kap

TL2 naik 10%

Peningkatan total biayaoutbound karena kap

TL2 turun 10%

26

Kapasitas TL2 naik / turun 10%

1.920,00

591,46

99,27 81,06

640

181,99

1.901,80

202,65453,85

575,44

1.920,00

474,52

0,00

500,00

1.000,00

1.500,00

2.000,00

2.500,00

TL2COST HOLDTL2COST LTLCOST HOLDLTLCOST

Skenario awal Kap TL2 naik 10% Kap TL2 turun 10%

27

Rute dan skedul pengiriman dengan kenaikan kapasitas TL2 10%

28

Rute dan skedul pengiriman dengan kenaikan kapasitas TL2 10%

29

Kesimpulan1. Fungsi tujuan dipengaruhi oleh kapasitas kendaraan

konsolidasi, tarif LTL carrier, tarif biaya simpan, serta alternatif ketersediaan pengiriman.

2. Peningkatan kapasitas kendaraan mengakibatkan pengurangan nilai fungsi tujuan yang optimal, demikian juga sebaliknya

3. Kenaikan tarif LTL carrier menyebabkan meningkatnya nilai fungsi tujuan yang optimal, demikian juga sebaliknya

4. Kenaikan biaya simpan menyebabkan kenaikan fungsi tujuan melalui peningkatan total biaya simpan baik yang ditimbulkan pengiriman melalui konsolidasi maupun melalui LTL carrier, demikian juga sebaliknya

5. Pembatasan alternatif pengiriman order dengan maniadakan pilihan konsolidasi akan menaikkan nilai fungsi tujuan melalui peningkatan biaya perngiriman dengan LTL carrier. Demikian juga sebaliknya.

30

Saran

� Persoalan yang lebih komplek dengan peningkatan jumlah zone, order dan retailer yang banyak serta perlu diuji coba untuk mengetahui perilaku model yang lebih luas.

� Pengembangan model masih sangat terbuka dengan menambah kompleksitas rantai pasok

31

ReferencesAttanasio, A. dkk. (2007), “Integrated Shipment Dispatching and Packing Problems: A Case

Study”, Journal Math Model Algorithm, Vol. 6, hal. 77-85.

Ballou, R.H. (2004), Business Logistics / Supply Chain Management. 5th edition, Prentice Hall.

Bohman, R. (2006), “Smart Ways You can Cut LTL Costs”, Logistics Management, Vol. 45, No. 10, hal. 37–40.

Burwell, T.H. dkk. (1997), “Economic Lot Size Model For Price-Dependent Demand Under Quantity and Freight Discounts”, International Journal of Production Economics, Vol. 48, hal. 141–155.

Carter, J.R. dkk. (1995). “The Effect of Less-Thantruckload Rates on The Purchase Order Lot Size Decision”, Transportation Journal, Vol. 34, No. 3, hal. 35–44.

Carter, J.R., dan Ferrin, B. (1996), “Transportation Costs and Inventory Management: Why Transportation Costs Matter”, Production and Inventory Management Journal, Vol. 37, No. 3, hal. 58–62.

Chan, L.M. dkk. (2002), “Effective Zero-Inventory-Ordering Policies for The Single Warehouse Multiretailer Problem with Piecewise Linear Cost Structures”, Management Science, Vol. 48, No. 11, hal. 1446–1460.

Clark, A.R., dan Clark, S.J. (2000), “Rolling-Horizon Lot-Sizing when Set-Up Times are Sequence-Dependent”, International Journal of Production Research, Vol. 38, No. 10, hal. 2287–2307.

32

ReferencesCopra, S. dan Meindl, P. (2007), Supply Chain Management, 3rd ed., Pearson Education,

Upper Saddle River, New Jersey.

Croxton, K.L. dkk. (2003), “Models and Methods For Merge-In-Transit Operations”, Transportation Science, Vol. 37, No. 1, hal. 1–22.

Diaby, M., dan Martel, A. (1993), “Dynamic Lot Sizing for Multiechelon Distribution Systems with Purchasing and Transportation Price Discounts”, Operations Research, Vol. 41, No. 1, hal. 48–59.

Ertogral, K. dkk. (2007), “Production and Shipment Lot Sizing in A Vendor–Buyer Supply Chain with Transportation Cost”, European Journal of Operational Research, Vol. 176, hal 1592–1606.

Fisher, M.L. (1997), “What is The Right Supply Chain for Your Product?”, Harvard Business Review, Vol. 75, No. 2, hal. 105–116.

Garg, M. dan Cole, S.J. (2006), “Models and Algorithms for The Design of Survivable Multicommodity Flownetworks with General Failure Scenarios”. Omega, Vol. 36, hal. 1057 – 1071.

Ghiani, G. etc. (2004), Introductionto Logistics Systems Planning and Control, John Wiley & Sons Ltd., England.

Hill, J. dan Galbreth, M. (2008), “A Heuristic for Single – Warehouse Multi Retailer Supply Chains with All-Unit Transportation Cost Discounts”, European Journal of Operational Research, Vol. 187, hal. 473-482.

33

ReferencesLeBlanc, L. dkk. (2004), “Nu-Kote’s Spreadsheet Linear Programming Models for Optimizing

Transportation”, Interfaces, Vol. 34, No. 2, hal. 139–149.Leenders, M. dkk (2002). Purchasing and Supply Management, 12th ed. McGraw-Hill, New

York.Ng, C.T. dkk. (2001), “Coordinated Replenishments with Alternative Supply Sources in Two-

Level Supply Chains”, International Journal of Production Economics, Vo. 73, hal. 227–240.

Nurwidiana (2007), “Pengembangan Model dan Algoritma Common Replenishment Epoch untuk Koordinasi Rantai Pasok dengan Mempertimbangkan Kelayakan KonsolidasiPengiriman”, Thesis, Institut Teknologi Sepuluh Nopember, Surabaya

Russell, R.M. dan Krajewski, L.J. (1991), “Optimal Purchase and Transportation Cost Lot SizingfFor A Single Item”, Decision Sciences, Vol. 22, hal 940–951.

Russell, R.M. dan Krajewski, L.J. (1992), “Coordinated Replenishments from A Common Supplier”, Decisions Sciences, Vol. 23, hal. 610–632.

Sumner, M. (2005), Enterprise Resource Planning. 1st Edition, Prentice Hall.Swenseth, S. dan Godfrey, M. (2002), “Incorporating Transportation Costs into Inventory

Replenishment Decisions”, International Journal of Production Economics, Vol. 77, hal. 113–130.

Tersine, R.J. dan Barman, S. (1991), “Economic Inventory / Transport Lot Sizing with Quantity and Freight Rate Discounts”, Decision Sciences, Vol. 22, hal. 1171–1179.

Thomas, D.J. dan Griffin, P.M. (1996), “Coordinated Supply Chain Management”, European Journal of Operational Research, Vol. 94, hal. 1–15.

Vroblefski, M. dkk. (2000), “Efficient Lot-Sizing Under Differential Transportation Cost Structure for Serially Distributed Warehouses”, European Journal of Operational Research, Vol. 127, hal. 574–593.