Warehousing

Function

Storage in Transit Inventory

Economic Service – Consolidation & Break Bulk - Spot Stocking

– Assortment - Full Line Stocking

– Postponement - Product Support

– Stockpiling - Market Presence

– Reverse Logistics

Consolidation & Break Bulk

Reduce Transportation Cost by using

warehouse capability to increase

shipment economic of scale

Consolidation, warehouse receives

materials from number of sources which

combined into a large single shipment

to a specific destination

Break-Bulk, operator receives a single

large shipment and arrange for delivery

to multiple destination

Consolidation

Plant A

Plant B

Plant C

Consolidation

Warehouse X Y Z

Break-Bulk

Customer X

Customer Y

Customer Z

Break-Bulk

Warehouse Plant A

Assortment

Reconfigure freight as it flows from origin to destination

Cross Docking Mixing Assembly

Cross-Dock

Plant A

Plant B

Plant C

Distribution

Warehouse Customer Y

Customer Z

Customer X

Combine inventory from multiple origins into an assortment for specific customer

Mixing

Plant A

Plant B

Plant C

Transit Mixing

Point

A B C

Product D

D

A

A

A B

B

B C

C

D

Customer W

Customer Y

Customer X

Customer Z

Assembly

Vendor A

Vendor B

Vendor C

Lead Supplier

Warehouse Assy. Plant

Procure inventory from multiple Vendor to support manufacturing operations

Postponement

Warehouse postpone commitment to final

product configuration by completing

final packaging, labeling, and light

manufacturing

Reduced Risk Lower Inventory

10

Stockpiling

Accommodate seasonal production or demand

Buffer Stock

11

Reverse Logistics

Perform physical work related to product

recall, reclamation, disposal of

overstock and damage inventory

Control Regular

12

Service

Establishing warehouse to service a specific

market area

- Spot Stocking

- Full Line Stocking

- Product Support

- Market Presence

13

Spot Stocking

Spot Stocked in a Local Market Warehouse in

Anticipation of Responding to Customer Need

During the Critical Sales Period Rather Than

Maintaining Inventory in a Warehouse Year-

round

Use temporarily Warehouse for Time Limited

Period

14

Full Line Stocking

Warehouse can provide one-stop

shopping capability for goods from

multiple manufacturers

Use Permanent Warehouse for Unlimited Time Period

15

Production Support

Stock Inventory to Support Manufacturing

Operation

Support Warehouse Containing an Inventory of

Processed Materials, Components and

Subassembly

16

Market Presence

Respond faster to customer needs

Increase Market Share and Profitability

17

Warehouse Operation

The objective is to efficiently receive inventory, possible store it until required

by the market, assembly it into complete orders, and initiate movement to

customer

Handling Storage Receiving - Active

In Storage Handling - Extended

Shipping

18

Warehouse Ownership

Private Public Contract

19

Warehouse Size

Min = SSL + Q

Max = SSL+T + Q

20

Flow of Goods in Warehouse

Receiving

Holding

Picking

Shipping

Flow of Goods in Warehouse

Receiving Receiving Receiving

Holding Holding Holding

Picking Picking Picking

Batch Forming

Packaging

Shipping

Storage Media

Physical Characteristics of Goods in

Stock

– Solid Goods: Stack, Rack, Drawers

Number of items of each product in a

customer order

Storage Plan

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Low Volume Low Volume

Receiving Dock

Shipping Dock

High Volume

Storage/Retrieval Transport

1. Picker to Product System

• A team of human order pickers, traveling to

storage location

2. Product to Picker System

• An automated device, delivering items to

stationary order pickers

• AS/RS

Block Stacking System

Item Retrieval by Trolley

x

y

A/R Machine S

ide

ais

le

Central aisle

Item Storage and Retrieval By AS/RS

and Belt Conveyor

Sid

e a

isle

Location and Site

Criteria

Services Operating Cost

Faktor Lokasi

1. Pasar Dan Bahan Baku

Jasa Semen

Fragile Kertas

Berat Agro Industri

SERVICES COST

Faktor Lokasi

2. Tangible

. Transportasi . Utilitas

. Tenaga Kerja . Biaya Konstruksi

. Energi . Pajak

. Tanah . Bahan Penolong

. Insentif . Dll

Faktor Lokasi

3. Intangible

– Iklim

– Peraturan

– Stabilitas Politik

– Kemudahan Ekspansi

– Budaya

– Polusi

– Dll

Tahapan Pemilihan Lokasi

Regional

Makro

Community

Mikro

Site

Metoda Pemilihan

Gravitasi

BEP

Transportasi

Point Rating

Simulasi

Metoda Gravitasi

Minimasi Ongkos Transportasi

Faktor Faktor Lain Tetap

(Sama Untuk Semua Pilihan Lokasi)

Menggunakan Koordinat Cartesian

Sebagai Basis

Formula Metoda Gravitasi

J = Ti Bi Ji /Ti Bi

Dimana:

Ti : Biaya Transport Dari Tiap Titik i Ke Lokasi

(Rp/satuan /Km)

Bi : Berat Yang Diangkut Dari / Ke Lokasi i

Ji : Koordinat Dari Titik i

Contoh Metoda Gravitasi

Data pasar

– A : 10 ton; 5000/ton/km

– B : 2 ton; 8000/ton/km

– C : 8 ton ; 4000/ton/km

Koordinat:

– A (13, 22) ; B (95,84) ; C (118,41)

Contoh Metoda Gravitasi

Jx = (5x10x13) + ( 8x2x95) + ( 4x8x118)

(5x10) + ( 8x2) + ( 4x8)

= 91,3 KM

JY = (5x10x22) + ( 8x2x84) + ( 4x8x41)

(5x10) + ( 8x2) + ( 4x8)

= 38,3 KM

Metoda BEP

A

B

•Faktor Yang Lain Tetap ( Sama ) •Fix Cost Dan Variable Cost Berbeda

Metoda BEP

Total Cost Lokasi A = Total Cost Lokasi B

FA + Q. VA = FB + Q.VB

Q = (FA - FB )/ (VB - VA )

Metoda Transportasi

Multi Lokasi

Faktor Lain Sama Kecuali Ongkos

Transport

Metoda Point Rating

Menggabungkan Faktor Tangible &

Faktor Intangible

Menggunakan Pendekatan Kwalitatif

Dan Kwantitatif

Prosedur

Identifikasikan Faktor Yang Relevan

Tentukan Bobot Setiap Faktor

Tentukan Rating Faktor Pada Setiap Lokasi

Hitung Bobot Score Pada Setiap Lokasi Untuk Setiap Faktor

Jumlahkan Bobot Skor Pada Setiap Lokasi

Pilih Lokasi Yang Memiliki Skor Tertinggi

Contoh

Warehouse Design

Criteria

Services Cost

Warehouse Cost

Receiving Cost

Holding Inventory Cost

Retrieving Cost

Assembling to customer order Cost

Shipping Cost

Factors To Be Considered

Physical characteristics of products

Number of items in stock

Rate of storage and retrieval request

Warehouse Design

1. Determining the capacity: length, width and height

2. Locating and sizing: receiving, shipping and storage zones (including number of I/O port, number, length and width of the aisles of storage zone and the orientation of stack/racks/drawers)

3. Selecting the storage medium

4. Selecting the storage/retrieval transport mechanism

Basic Warehouse Design

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Receiving Area

Order Picking Area

Packaging or Unitizing Area

Staging Area

Bulk Storage Area

Rack Storage Area

Selecting The Storage/Retrieval

Physical Characteristics of goods

Packaging at the arrival

Composition of out going lots

Stack Rack Drawers

Sizing Receiving &Shipping

The Number of Truck Dock

ND = [dt/QT]

ND : Number of Dock Truck

d : Daily demand from all order

t : Average time required to load/unload a truck

Q : Truck Capacity

T : Daily time available to load/unload a truck

Example Average daily demand is 27.000 units, outgoing shipment are performed by trucks, with capacity equal to 850 units. Average time to load a truck is 280 minutes and 15 working hours are available

every day

Number of dock truck:

ND = [d.t/Q.T]

ND = [27.000x280/850x(15x60)]

ND = 10

Storage Policy

1. Dedicated Storage policy: – Product is assigned at pre-established set position

– Easy to implement but causes an under utilization

2. Random Storage policy: – Product allocation is decided dynamically on the basis of:

Current warehouse occupation

Future arrival and request-forecast

– Allow a higher utilization of space but requires:

Each item be automatically identified

Update database of current position of all items

Storage Policy

3. Class Based Storage policy:

– Product are divided into a number of

categories according to their demand

– Each category is associated with asset of

zones where the goods are stored according

to random storage policy

Sizing of Storage Area

Dedicated Storage policy:

MD = ∑ max Ij(t)

MD : Number of required storage location

Ij(t) : Inventory level of item j at time t

n : Number of item

Random Storage policy:

Mr = max∑ Ij(t) ≤ MD

n

j=1

Example of Storage Area

Product Lot Safety Stock

A 500 100

B 200 80

Dedicated Storage policy:

MD = ∑ max Ij(t)

= 600 +280 = 880

Random Storage policy:

Mr = max∑ Ij(t) ≤ MD

= 600 + 180 = 780

Length and Width of Storage

Length: Lx = ( ax + ½ wx )nx

Width : Ly = ( ay ny + wy )

Dimana: ax : Occupation of a unit load along the direction of x

ay : Occupation of a unit load along the direction of y

wx: Width of side aisle along the direction of x

wy: Width of side aisle along the direction of y

nx: number of storage location along the direction of x

ny: number of storage location along the direction of y

A Traditional Storage Zone

Lx

LyWy

Wx

Model of Sizing The Storage Zone

Minimize:

Subject to:

v

wn

v

nw

yyyxxx

22

1

integer0 ,nn

mnnn

yx

zyx

Determining nx and ny

Number of Storage Location Along Y Direction

Number of Storage Location Along X Direction

zy

xx

yn

wm'n

2

12

xxz

y

xwn

m'n

212

yyxx 'nn'nn and

Example

Berapa ukuran luas gudang untuk menampung produk A dan B diatas jika:

1. Jika setiap pallet produk A dan B memiliki dimensi yang sama dan memerlukan 1.05x1.05 m2 area.

2. Barang akan diletakkan diatas rak dimana setiap raknya terdiri atas 4 tingkat.

3. Lebar gang utama adalah 4 m dan gang lainnya 3,5 m

4. Cara penempatan barang dengan menggunakan random policy

Example

25.32

405.1

05.17802'

05.605.142

05.1780'

25.3

25.3

yn

xn

Example

•nx = 6 and ny = 33

•Length: Lx = ( ax + ½ wx )nx

= ( 1.05 +(3.5/2))x6

= 16.8 m

•Width : Ly = ( ay nx + wy )

= (1.05x33+4)

= 39.65 m

Case

Suatu sistem logistik terdiri atas satu unit produksi, satu depot dan 10 agen. Unit produksi berkapasitas 100.000 unit per tahun, ongkos set up sebesar Rp.25.000.000/set up dan ongkos simpan pada eselon produksi sebesar Rp. 20.000/unit/tahun, waktu pengiriman barang dari unit produksi ke depot 1 bulan sedangkan dari depot ke rertailer ditunjukkan pada tabel berikut. Ongkos pemesanan dari depot ke unit produksi sebesar Rp 1000.000/pesan, dan ongkos transport dari unit produksi ke depot sebesar Rp. 50.000/unit, sedangkan ongkos simpan pada eselon depot sebesar Rp.40.000/unit/tahun. Adapun data pada agen ditunjukkan pada tabel berikut

Data Pada Agen

Agen Aj Hj Bj Dj Sj Ldj Cdj

j Rp/Psn Rp/unit/thn Rp/unit unit/thn unit/thn thn Rp/unit

1 50000 4000 50000 5000 500 0.05 9500

2 40000 6000 50000 4000 400 0.03 8000

3 30000 8000 35000 4500 500 0.10 9000

4 60000 10000 40000 5000 500 0.10 8000

5 75000 12000 40000 6000 600 0.05 6000

6 65000 8000 30000 5500 550 0.05 6000

7 70000 10000 40000 6000 600 0.10 9000

8 60000 8000 45000 5000 500 0.05 6000

9 55000 12000 50000 4000 400 0.05 6000

10 70000 8000 40000 5000 500 0.03 5000

Berapa ukuran luas gudang di unit produksi, depot dan setiap agen:

1. Jika setiap pallet produk memiliki dimensi yang sama dan memerlukan 1.2x1.2 m2 area.

2. Barang akan diletakkan diatas rak dimana setiap raknya terdiri atas 3 tingkat.

3. Lebar gang utama adalah 4 m dan gang lainnya 3,5 m

4. Cara penempatan barang dengan menggunakan random policy