pert 13 aggregate plan 2

Aggregate PlanningAggregate Planning

Operations Management Operations Management

Chapter 14Chapter 14

Dr. Achmad Hidayat.,SE.,M.Com.,M.hilDr. Achmad Hidayat.,SE.,M.Com.,M.hil

Copyright 2009 John Wiley & Sons, Inc.Copyright 2009 John Wiley & Sons, Inc. 14-14-22

Lecture OutlineLecture Outline

The Sales and Operations Planning The Sales and Operations Planning ProcessProcess

Strategies for Adjusting CapacityStrategies for Adjusting Capacity Strategies for Managing DemandStrategies for Managing Demand Quantitative Techniques for Aggregate Quantitative Techniques for Aggregate

PlanningPlanning Hierarchical Nature of PlanningHierarchical Nature of Planning Aggregate Planning for ServicesAggregate Planning for Services

IntroductionIntroduction

Perencanaan Perencanaan long term planlong term plan perusahaan dijabarkan perusahaan dijabarkan lebih lanjut dalam lebih lanjut dalam middle planmiddle plan..

Perencanaan ini berupa Perencanaan ini berupa business planbusiness plan yang berisikan yang berisikan rencana kegiatan perusahaan dalam jangka waktu 3 rencana kegiatan perusahaan dalam jangka waktu 3 sampai 18 bulan yang akan datang.sampai 18 bulan yang akan datang.

Business PlanBusiness Plan ini didasarkan atas prakiraan kondisi ini didasarkan atas prakiraan kondisi perekonomian, industri, ataupun persaingan masa perekonomian, industri, ataupun persaingan masa datang, dan mencerminkan strategi perusahaan dalam datang, dan mencerminkan strategi perusahaan dalam mencapai sasaranmencapai sasaran


© Wiley 2009© Wiley 2009

The Role of the Aggregate PlanThe Role of the Aggregate Plan

Capacity Planning, Aggregate Planning, Master Schedule, and Short-Capacity Planning, Aggregate Planning, Master Schedule, and Short-Term SchedulingTerm Scheduling

Capacity PlanningCapacity Planning1. Facility Size1. Facility Size2. Equipment Procurement2. Equipment Procurement

Aggregate PlanningAggregate Planning1. Facility Utilization1. Facility Utilization2. Personnel needs2. Personnel needs3. Subcontracting3. Subcontracting

Master ScheduleMaster Schedule1. MRP1. MRP2. Disaggregation of master plan2. Disaggregation of master plan

Short-term SchedulingShort-term Scheduling1. Work center loading1. Work center loading2. Job sequencing2. Job sequencing

Long-termLong-term

Intermediate-termIntermediate-term

Intermediate-termIntermediate-term

Short-termShort-term

What is Aggregate Plan?What is Aggregate Plan?

Bagian rencana bisnis yang menyangkut Bagian rencana bisnis yang menyangkut kegiatan produksi atau operasi disebut rencana kegiatan produksi atau operasi disebut rencana produksi atau perencanaan agregatproduksi atau perencanaan agregat

Agregat plan Agregat plan merupakan jantung dari merupakan jantung dari perencanaan jangka menengah.perencanaan jangka menengah.

Tujuannya untuk mengembangkan suatu Tujuannya untuk mengembangkan suatu rencana produksi secara menyeluruh yang rencana produksi secara menyeluruh yang flexibel dan optimal.flexibel dan optimal.


What is Aggregate Plan?What is Aggregate Plan?

Proses agregasi Proses agregasi (aggregation)(aggregation) ialah ialah pengelompokan beberapa jenis item pengelompokan beberapa jenis item menjadi menjadi product family.product family.

Proses disagregasi Proses disagregasi (disaggregation)(disaggregation) adalah proses derivasi adalah proses derivasi product familyproduct family menjadi item.menjadi item.


Aggregate Aggregate PlanningPlanning

Hirarki produkHirarki produk

TypeType: kelompok beberapa : kelompok beberapa product familiesproduct families.. Product familyProduct family: kelompok beberapa : kelompok beberapa itemsitems.. ItemItem: produk akhir individual yang dibeli (digunakan) : produk akhir individual yang dibeli (digunakan)

oleh konsumen.oleh konsumen. Biasanya hirarki tersebut dimulai dari Biasanya hirarki tersebut dimulai dari product familyproduct family, ,

karena bila sebuah pabrik membuat lebih dari satu karena bila sebuah pabrik membuat lebih dari satu jenis jenis typetype maka operasi perusahaan itu akan menjadi maka operasi perusahaan itu akan menjadi sangat kompleks.sangat kompleks.

Pengelompokan sejumlah Pengelompokan sejumlah itemitem ke dalam sebuah ke dalam sebuah product familyproduct family dilakukan dengan teknik dilakukan dengan teknik Group Group TechnologyTechnology (GT). (GT).

Contoh Proses AgregasiContoh Proses Agregasi

IBM memproduksi komputer laptop, desktop, notebook IBM memproduksi komputer laptop, desktop, notebook dan mesin teknologi tinggi lainnya. Proses agregasi dan mesin teknologi tinggi lainnya. Proses agregasi adalah pengelompokkan jenis – jenis komputer tersebut adalah pengelompokkan jenis – jenis komputer tersebut ke dalam family product (misalnya famili komputer).ke dalam family product (misalnya famili komputer).Sebuah rumah sakit bisa melakukan agregasi jasa yang Sebuah rumah sakit bisa melakukan agregasi jasa yang diberikan menjadi jumlah perawat atau dokter yang diberikan menjadi jumlah perawat atau dokter yang dibutuhkan.dibutuhkan.PT. Telkomsel bisa melakukan agregasi jumlah unit PT. Telkomsel bisa melakukan agregasi jumlah unit penjualan kartu prabayar (kartu simpati) dan kartu penjualan kartu prabayar (kartu simpati) dan kartu pascabayar (kartu hallo) menjadi jumlah rupiah pascabayar (kartu hallo) menjadi jumlah rupiah penjualan yang diterima. Kartu hallo juga terdiri dari penjualan yang diterima. Kartu hallo juga terdiri dari beberapa item.beberapa item.

Chase StrategiesChase Strategies Match demand during the planning horizon by eitherMatch demand during the planning horizon by either Vary workforce or vary output rateVary workforce or vary output rate

Level StrategiesLevel Strategies Maintain a constant workforce level or constant output Maintain a constant workforce level or constant output

rate during the planning horizonrate during the planning horizon Constant workforce or constant output rateConstant workforce or constant output rate

Mixed StrategiesMixed Strategies Combined several strategiesCombined several strategies

PURE PURE STRATSTRATEGIESEGIES

Level ProductionLevel Production

ProductionProduction

DemandDemand

Uni

tsU

nits

TimeTime

Chase DemandChase Demand

ProductionProduction

DemandDemand

Uni

tsU

nits

TimTimee

14-14-1414

Strategies for Managing Demand

Pergeseran permintaan Pergeseran permintaan dalam periode waktu laindalam periode waktu lain Incentives Sales promotions Advertising campaigns

Menawarkan produk atau Menawarkan produk atau layanan dengan pola layanan dengan pola permintaan counter-permintaan counter-cyclicalcyclical

Partnering with suppliers to reduce information distortion along the supply chain


Quantitative Techniques For AP

Pure Strategies Mixed Strategies Linear Programming Transportation Method Other Quantitative

Techniques


Pure StrategiesPure Strategies

Hiring costHiring cost = $100 per worker= $100 per worker

Firing costFiring cost = $500 per worker= $500 per worker

Inventory carrying costInventory carrying cost = $0.50 pound per quarter= $0.50 pound per quarter

Regular production cost per poundRegular production cost per pound = $2.00= $2.00

Production per employeeProduction per employee = 1,000 pounds per quarter= 1,000 pounds per quarter

Beginning work forceBeginning work force = 100 workers= 100 workers

QUARTERQUARTER SALES FORECAST (LB)SALES FORECAST (LB)

SpringSpring 80,00080,000SummerSummer 50,00050,000FallFall 120,000120,000WinterWinter 150,000150,000

Example:Example:


Level Production StrategyLevel Production StrategyLevel production

= 100,000 pounds(50,000 + 120,000 + 150,000 + 80,000)

4

Spring 80,000 100,000 20,000Summer 50,000 100,000 70,000Fall 120,000 100,000 50,000Winter 150,000 100,000 0

400,000 140,000Cost of Level Production Strategy

(400,000 X $2.00) + (140,00 X $.50) = $870,000

SALES PRODUCTIONQUARTER FORECAST PLAN INVENTORY


Chase Demand StrategyChase Demand Strategy

SpringSpring 80,00080,000 80,00080,000 8080 00 2020SummerSummer 50,00050,000 50,00050,000 5050 00 3030FallFall 120,000120,000 120,000120,000 120120 7070 00WinterWinter 150,000150,000 150,000150,000 150150 3030 00

100100 5050

SALESSALES PRODUCTIONPRODUCTION WORKERSWORKERS WORKERSWORKERS WORKERSWORKERSQUARTERQUARTER FORECASTFORECAST PLANPLAN NEEDEDNEEDED HIREDHIRED FIREDFIRED

Cost of Chase Demand StrategyCost of Chase Demand Strategy

(400,000 X $2.00) + (100 x $100) + (50 x $500) = $835,000 (400,000 X $2.00) + (100 x $100) + (50 x $500) = $835,000


Mixed StrategyMixed Strategy

Combination of Level Production and Chase Demand strategies

Examples of management policies no more than x% of the workforce can be

laid off in one quarter inventory levels cannot exceed (up to) x

dollars Many industries may simply shut down

manufacturing during the low demand season and schedule employee vacations during that time


General Linear Programming (LP) Model

LP gives an optimal solution, but demand and costs must be linear

Let Wt = workforce size for period t Pt =units produced in period t It =units in inventory at the end of period t Ft =number of workers fired for period t Ht = number of workers hired for period t


LP MODELMinimize Z = $100 (H1 + H2 + H3 + H4)

+ $500 (F1 + F2 + F3 + F4)

+ $0.50 (I1 + I2 + I3 + I4)

+ $2 (P1 + P2 + P3 + P4)

Subject to

P1 - I1 = 80,000 (1)

Demand I1 + P2 - I2 = 50,000 (2)

constraints I2 + P3 - I3 = 120,000 (3)

I3 + P4 - I4 = 150,000 (4)

Production 1000 W1 = P1 (5)

constraints 1000 W2 = P2 (6)

1000 W3 = P3 (7)

1000 W4 = P4 (8)

100 + H1 - F1 = W1 (9)

Work force W1 + H2 - F2 = W2 (10)

constraints W2 + H3 - F3 = W3 (11)

W3 + H4 - F4 = W4 (12)


Transportation MethodTransportation Method

11 900900 10001000 100100 50050022 15001500 12001200 150150 50050033 16001600 13001300 200200 50050044 30003000 13001300 200200 500500

Regular production cost per unitRegular production cost per unit $20$20Overtime production cost per unitOvertime production cost per unit $25$25Subcontracting cost per unitSubcontracting cost per unit $28$28Inventory holding cost per unit per periodInventory holding cost per unit per period $3$3Beginning inventoryBeginning inventory 300 units300 units

EXPECTEDEXPECTED REGULARREGULAR OVERTIMEOVERTIME SUBCONTRACTSUBCONTRACTQUARTERQUARTER DEMANDDEMAND CAPACITYCAPACITY CAPACITYCAPACITY CAPACITYCAPACITY


Transportation TableauTransportation Tableau

UnusedPERIOD OF PRODUCTION 1 2 3 4 Capacity Capacity

Beginning 0 3 6 9

Inventory 300 — — — 300

Regular 600 300 100 — 1000

Overtime 100 100

Subcontract 500

Regular 1200 — — 1200

Overtime 150 150

Subcontract 250 250 500

Regular 1300 — 1300

Overtime 200 — 200

Subcontract 500 500

Regular 1300 1300

Overtime 200 200

Subcontract 500 500

Demand 900 1500 1600 3000 250

1

2

3

4

PERIOD OF USE

20 23 26 29

25 28 31 34

28 31 34 37

20 23 26

25 28 31

28 31 34

20 23

25 28

28 31

20

25

28


Burruss’ Production PlanBurruss’ Production Plan

11 900900 10001000 100100 00 50050022 15001500 12001200 150150 250250 60060033 16001600 13001300 200200 500500 1000100044 30003000 13001300 200200 500500 00

TotalTotal 70007000 48004800 650650 12501250 21002100

REGULARREGULAR SUB-SUB- ENDINGENDINGPERIODPERIOD DEMANDDEMAND PRODUCTIONPRODUCTION OVERTIMEOVERTIME CONTRACTCONTRACT INVENTORYINVENTORY


ItemsItems

Product lines Product lines or familiesor families

Individual Individual productsproducts

ComponentsComponents

Manufacturing Manufacturing operationsoperations

Resource Resource LevelLevel

PlantsPlants

Individual Individual machinesmachines

Critical Critical work work

centerscenters

Production Production PlanningPlanning

Capacity Capacity PlanningPlanning

Resource requirements

plan

Rough-cut capacity

plan

Capacity requirements

plan

Input/ output control

Sales and Operations

Plan

Master production schedule

Material requirements

plan

Shop floor

schedule

All All work work

centerscenters

Hierarchical Nature of Planning

Disaggregation: process of breaking an aggregate plan into more detailed plansDisaggregation: process of breaking an aggregate plan into more detailed plans

Aggregate Planning in ServicesAggregate Planning in Services

Controlling the cost of labor is criticalControlling the cost of labor is critical

1.1. Accurate scheduling of labor-hours to Accurate scheduling of labor-hours to assure quick response to customer assure quick response to customer demanddemand

2.2. An on-call labor resource to cover An on-call labor resource to cover unexpected demandunexpected demand

3.3. Flexibility of individual worker skillsFlexibility of individual worker skills

4.4. Flexibility in rate of output or hours of Flexibility in rate of output or hours of workwork

Five Service ScenariosFive Service Scenarios

RestaurantsRestaurants Smoothing the production processSmoothing the production process

Determining the optimal workforce Determining the optimal workforce sizesize

HospitalsHospitals Responding to patient demandResponding to patient demand

Five Service ScenariosFive Service Scenarios

National Chains of Small Service National Chains of Small Service FirmsFirms Planning done at national level and Planning done at national level and

at local levelat local level

Miscellaneous ServicesMiscellaneous Services Plan human resource requirementsPlan human resource requirements

Manage demandManage demand


Aggregate Planning for ServicesAggregate Planning for Services

Kebanyakan layanan tidak dapat Kebanyakan layanan tidak dapat diinventarisasidiinventarisasiPermintaan untuk layanan sulit untuk Permintaan untuk layanan sulit untuk memprediksimemprediksiKapasitas juga sulit untuk memprediksiKapasitas juga sulit untuk memprediksiKemampuan pelayanan harus disediakan di Kemampuan pelayanan harus disediakan di tempat yang tepat dan waktutempat yang tepat dan waktuBuruh biasanya merupakan sumber yang Buruh biasanya merupakan sumber yang paling menghambat untuk layananpaling menghambat untuk layanan


Copyright 2009 John Wiley & Sons, Inc.Copyright 2009 John Wiley & Sons, Inc.All rights reserved. Reproduction or translation All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without of the 1976 United States Copyright Act without express permission of the copyright owner is express permission of the copyright owner is unlawful. Request for further information should unlawful. Request for further information should be addressed to the Permission Department, be addressed to the Permission Department, John Wiley & Sons, Inc. The purchaser may John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only make back-up copies for his/her own use only and not for distribution or resale. The Publisher and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, assumes no responsibility for errors, omissions, or damages caused by the use of these or damages caused by the use of these programs or from the use of the information programs or from the use of the information herein. herein.

pert 13 aggregate plan 2

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