Product, Process and Schedule Design.ppt

Product, Process, and Product, Process, and Production ScheduleProduction Schedule

Produk, Proses, Production Schedule, Lokasi Pabrik

Mulai

Formulasikan Tujuan Perencanaan Fasilitas

Apa Bagaimana KapanBerapa banyak

Berapa lama

Dimana

Produk Proses Production schedule Lokasi pabrik

Tentukan produk

Tentukan proses

Tentukanproduction schedule

Tentukan lokasi pabrik

Informasi Produk, Proses, Production Schedule, dan Lokasi Pabrik

Produk, Proses, Production Schedule, Lokasi PabrikInformasi Produk, Proses, Production Schedule, dan Lokasi Pabrik

Model Layout Fasilitas

Teori Antrian Model matematik Simulasi

Model Kualitatif:§ Peta hubungan§ Indeks kedekatan

Informasi Luas Lantai:§ Luas lantai yang dibutuhkan§ Lebar gang§ Tata letak yang ada (?)

Model Kuantitatif:§ Peta from-to§ Aliran material§ Ongkos material handling

Algoritma

Algoritma berbasis kedekatan Algoritma berbasis jarak/ongkos

CORELAP/BLOCPLAN/... CRAFT/BLOCPLAN LayOPT/...

Pilih Teknik/Metode untuk Perancangan Tata Letak Fasilitas

Facilities Planning Process1. Define the products to be manufactured

2. Specify the manufacturing processes and related activities required to produce the products.

3. Determine the interrelationships among all activities

4. Determine the space requirements for all activities

5. Generate alternative facilities plans

6. Evaluate the alternative facilities plans

7. Select the preferred facilities plan

8. Implement the facilities plan

9. Maintain and adapt the facilities plan

10. Update the products to be manufactured and redefine the objective of the facility.

Facilities Planning Process

In manufacturing, PP&S design of a product provides important data required for facilities layout design

The PP&S design process provide answer to the following questions:

– Product Design: What to produce (product drawing)– Process Design: Who should produce (make-or-buy

decisions) – (parts list)– Process Design: How to produce (precedence

diagram, BOM, route sheet, assembly chart, OPC)

– Schedule Design: How much to produce (lot size decisions)

– Schedule Design: When and How long to produce (production schedule)

PP&S Design

PP&S Design

Facilitiesdesign

Productdesign

Processdesign

Scheduledesign

Involves both determination of which products are to be produced and the detailed design of individual products.

The decisions – products to be produced are generally made by top management

Detailed operational specification, pictorial representation, and prototype of the product are important input for the facility designer

Detailed component part drawings are needed for each component

Product Design

The products manufactured by a company a provide important information about:

Processes or equipment required

Material handling methods and systems needed

The arrangement of production, auxiliary equipment, and service facilities

Before beginning to design a facility, analysts must know not only the types of products manufactured but also their production volume

Product Analysis

Exploded Assembly Drawing

Exploded Part Pothograph

Component Part Drawing

Component Part Drawing

Process DesignThe process designer is responsible for determining how the

product to be produced.Should a particular product, subassembly, or part to be

produced in-house or subcontracted to a supplier (make-or-buy decisions)

Determine how parts will be produced, which equipment will be used, how long it will take to perform the operation.

Identifying Required Processes– Parts List

Selecting the Required Processes– CAPP– The outputs from the process selection are the processes,

equipment, and raw materials required for the in-house production products (Route Sheet)

Part List

Bill of Materials

Bill of Material

Route Sheet

Process Design

Sequencing the Required Processes– Assembly Chart– Operation Process Chart (OPC)– Precedence Diagram

Assembly Chart

Operation Process Chart

Precedence Diagram

Schedule Design

How much to produce and When to produce Schedule design decisions impact machine selection,

number of machines, number of shifts, number of employees, space requirement, storage requirement, material handling equipment, etc.

Information is needed concerning production volume, trends, and the predictability of future demands for the products to be produced.

Market Information Process Requirement

– Process design: Determines the specific equipment types required to produce the product

– Schedule design: determines the number of each of equipment type required to meet the production schedule

Marketing Information

Market Analysis

Valuable Information From Marketing

Pareto Chart

Schedule Design

Specification of process requirements – Determine the quantity of components that

must be produced, including scrap allowance– Determine the equipment requirements for

each operation– Combines the operation requirements to

obtain overall equipment requirements Scrap estimates Equipment fraction

a : arrival rate of raw material p : production rate of a processing stationd : demand rate of a product from operation ks : scrap probability of an inspection station kn : number of operationsUntuk n = 1

Scrap Estimates

s

dpa

1

1

1

d

p

a

s

Production capacity must be planned for the production of scrap

Scrap is the material waste generated in the manufacturing process due to geometric or quality considerations

Scrap Estimates

1

1

d1

p1

a1

s1

Untuk n > 1, a1 = p1

dk-1 = pk

pk = dk + sk pk

dk = pk (1 – sk)

pk =

a1 = p1 =

dk

1 – skdn

(1 – s1) (1 – s2) … (1 – sn)1

1

dn

pn

an

sn

…

Scrap EstimatesA product have a market estimate of 97,000 components and requires three processing steps (turning, milling, and drilling) having scrap estimates of P1=0.04, P2=0.01, and P3=0.03. The market estimate is the output required from step 3.

components 219,10504.01

010,101


000,100


000,97

11

22

33

pa

pa

pa

components 219,105)04.01)(01.01)(03.01(

000,9711

pa

1

1

d

r

p

a

s

Rework Estimates

r : rework probability of an inspection station

rp

prpa

rs

dp

rspprpspd

1

1

1

Scrap Estimates

Production capacity must be planned for the production of scrap

Scrap is the material waste generated in the manufacturing process due to geometric or quality considerations

Pk represent the percentage of scrap produced on the kth operation

Ok represent the desired output on nondefect product from operation k

Ik represent the production input to operation k

Equipment Fractions

Equipment requirements are a function of the following factors:

Number of shift Setup times Degree of flexibility Layout type Total productive maintenance

Equipment Fractions

Equipment Selection

Analyst must know the required types and quantities of production and support equipment before making layout decisions

To determine the required types of equipment, one must first know what types of basic production processes are required (e.g., forging, drill holes, etc) and then match the available equipment with these process

Production equipment is typically classified into types based on its function

Design analyst must have at least a rough idea of what types of machines are capable of meeting processing needs, what support facilities are required, and approximately how many of these are need

The production equipment selection problem is critical in the design of a system

Equipment Selection

By determining the right quantities and types of equipment, one can achieve these benefits (Heragu and Kusiak, 1987): Make efficient use of the budget for capital

equipment purchases Make efficient use of maintenance and

operating budgets Increase machine utilization Make efficient use of available space because

fewer pieces of equipment are purchased to meet production needs now an in the future

Traditional Model

Based on the number of required products, desired production rate, production efficiency of the equipment required to process the products, standard processing times for the operations required and time for which machines are available.

Shubin and Madeheim (1951) presented formula for determining the type and quantity of required production equipment

Traditional Model

P : desired production rate, in units per day

: eficiency of the machine

: time (in hours) for which machine is available per day

t : time (in hours) required to process one unit of product at the machine

NM : number of units of the machine required

tP

NM

where [.] is smalest integer greater than or equal to

Traditional Model

Miller and Schmidt (1984) presented model of more than one stage of production using backward analysis to determine the desired production rate at each stage

It assumes that if an item is not processed within allowed tolerances, it cannot be used and is scrapped

In many situation, units that do not conform to production specifications may be reworked

It is difficult to handle the case when more than one product is processed

Traditional Model

Sl is the scrap rate at stage l, expressed as a

fraction, Nol is the number of good units required

at the output of stage l, and Nil is the number of units required at the input of state l, then the number of good units required at the output of stage l is equal to the number of input units minus scrap (Nol=Nil – SlNil)

l

olil S

NN

1

Linear Programming Model

NotationOi operation type i, i=1,2,…,o

Mi production equipment type i, i=1,2,…,m

Pi part type i, i=1,2,…,p

MHi material handling system type i, i=1,2,…,n

cij cost of performing operation Oi on production equipment type Mj

hij cost of handling part type Pi using material handling system type MHj


tij time required to perform operation Oi on production equipment type Mj

Sij time required to transport part type Pi using material handling carrier type MHj

j time available on production equipment type Mj

j time available on material handling carrier type MHj

NOi number of operations Oi to be performed

NPi number of units of part type Pi to be manufactured


Cj cost of production equipment type Mj

Hj cost of material handling system MHj

B total budget available

Decision Variablexij number of operations Oi to be performed on

production equipment type Mj

yij number of units of part type Pi to be transported on material handling system type MHj


NMj number of units of production equipment type Mj selected

NMHj number of units materal handling system type MHj selected

Objective FunctionM1 minimize the operating and handling cost of

the parts manufactured and the procurement cost of production and material handling equipment


n

iii

m

iii

p

i

n

jijij

o

i

m

jijij NMHHNMCyhxc

111 11 1

Minimize

Subject to

i

n

jij

jj

o

iijij

i

m

jij

NPy

NMxt

NOx

1

1

1

i = 1,2,…,o

j = 1,2,…,m

i = 1,2,…,p (4)

(3)

(2)


BNMHHNMC

NMHjys

n

iii

m

iii

j

p

iijij

11

1

j = 1,2,…,n

xij ≥ 0 and integer i = 1,2,…,o, j = 1,2,…,m (7)

yij ≥ 0 and integer i = 1,2,…,p, j = 1,2,…,n (8)

NMj ≥ 0 and integer j = 1,2,…,m (9)

NMHj ≥ 0 and integer j = 1,2,…,n (10)

(6)

(5)


n

iii

p

i

n

jijij NMHHyh

11 1

Minimize

Subject to

BNMHHn

iii

1

(11)

(12)

M2 selects material handling equipment assuming that production equipment has already been purchased

and constraints (6), (7), (10), dan (12)


m

iii

o

i

m

jijij NMCxc

11 1

Minimize

Subject to

BNMCm

iii

1

(13)

(14)

M3 select production equipment assuming that material handling equipment decisions have already been made

and constraints (4), (5), (9), dan (11)

ExampleAn automobile engine cylinder manufacturing company that supplies high-precision engines to a multinational car manufacturer plans to manufacture several models of cylinder. For planning purposes, it uses the following pseudoproducts: a “basic” engine cylinder, a high-technology model, an engine cylinder for sports cars, and a luxury-car cylinder. The marketing department has demand forecast figures aggregated for the four pseudomodels. It has been determined that 2000, 1500, 1800, and 1000 units of the basic, high-tech, sports, and luxury models, respectively, will be demanded during the next six months. The cylinder models require one or more of three operations, O1, O2, and O3. Three machine types and two material-handling systems are available for performing the three operations and trasporting the models. These are denoted as M1, M2, M3, and MH1, MH2, respectively. Each machine and handling system may be assumed to be available 90% of the time due to breakdowns, labor unavailability, and other factors. The costs of machine M1, M2, and M3 are $230,000, $250,000, and $310,000, and the costs of material-handling carriers MH1, MH2 are $90,000 and $130,000, respectively. The available budget is $10,000,000.

ExampleThe following two matrices show the cij’s and hij’s – that is, the cost of performing operation Oi on production equipment type Mj and the cost of handling part type Pi using material-handling system type MHj, respectively

The time required to perform operation Oi on production equipment type Mj is inversely proportional to the corresponding cost and can be determined using the matrix on the left and the formula tij=10/cij. Similary, the time required to transport part Pi on material-handling system MHj is inversely proportional to the corresponding cost and is determined using the matrix on the right and the formula sij=1/hij. The required numbers of each type of operation are 6000 for operation O1, 6000 for operation O2, and 4500 for operation O3. The total time for which the machines and material-handling systems are available is 333 units. Set up a model similar to model M1 and solve it using an available mixed-integer programming software. Determine the type and quantity of each production and handling equipment required

36

918

612

510

,

51012

4204

8126

ijij hc

Solution

NM1 = 14NM2 = 26NM3 = 0

NMH1 = 2NMH2 = 0

X11 = 210X12 = 5789X21 = 45X22 = 5954X31 = 4500X32 = 0

Y11 = 2000Y21 = 1500 Y31 = 1800Y41 = 1000

Objective value = 10028725

Machine Assignment Problem

How decisions regarding the assignment of machines to operators can affect the number of employees

The assignment of operators to semiautomatic production equipment

It is assumed: the machines are identical, setup time is constant, machine time is constant, inspect and pack part are constant, travel time between machines and prepare parts for machining are independent

Machine Assignment Problema : concurrent activity time (e.g., loading and unloading

machine

b : independent operator activity time (e.g., walking, inspecting, packing)

t : independent machine activity time (e.g., automatic machining time)

n’ : ideal number of identical machines to assign an operator

M : number of identical machines assigned an operator

Tc : repeating cycle time

Io : idle operator time during a repeating cycle

Im : idle time for each machine during a repeating cyle


ba

tan

Since a fractional number of machine cannot be assigned to an operator, consider what will happen if some integer number of machines, m, is assigned

nm

nmbamTI

nmtaT

nmI

nmbam

nmtaT

co

cmc

0

0

56


For the example, a = 2 minutes, b = 1 minutes, and t = 6 minutes. Therefore,

0

minute 1629

minutes 9123

machines, 3 m If

machines 67.221

62

o

cm

c

I

baTI

bamT

ba

tan

Personnel Requirements Analysis

To determine the actual number of employees needed by considering such factors as :

Labor force (unionized or nonunionized) Level of automation Production rate Management policies on subcontracting and overtime Salary rates in the area Health insurance rates Rules set by OSHA

Personnel Requirements AnalysisThe number of manufacturing employees required in a new facility is typically proportional to the volume and variety of production:

N : number of types of operationsOi : aggregate number of operation type I required on all the

pseudo (or real) products manufactured per dayTi : standard time required for an average operation Oi

H : total production time available per day : assumed production efficiency of the plant

n

i

ii

H

OTN

1

Space Requirements

The most difficult determination in facilities planning

The design year: 5-10 yearsUncertainty –due to impact of technology,

Changing product mix, changing demand levels, changing organization designs for the future

Needs a systematic approach: “From the ground up”

In manufacturing and office environments, space requirements should be determined first for individual workstations; next, departments, etc.

Modern manufacturing approaches can reduce space requirements.– Products are delivered to the points of use in smaller

lot and unit load size– Decentralised storage areas– Less inventories (using a pulled system)– Manufacturing cells– Companies are downsizing

Space Requirements

Workstation Specification (space for equipment, materials, and personnel)

Equipment Space consists of space for – the equipment; machine travel;machine maintenance;– plant services

Materials Space consists of space for – Receiving and storing materials; In-process materials;– Storing and shipping materials; Storing and shipping

waste and scrap; Tools, fixtures, jig, dies, and maintenance materials

Personnel area consists of space for – The operator; Material handling; Operator ingress and

egress.

Space Requirements

Department Specification

Aisle Arrangement

Visual Management and Space Requirement

Space Requirements

Simple rules of thumb are used to determine the extra space that is required (Heragu, 1997)

3 – 4 feet are added to the length and width of each machine or workstation

The additional space is calculated as a percentage of the actual area occupied by a workstation, typically 200% to 300%

Calculate the space required for the workstation, auxiliary equipment, operator space, incoming material and work in process space, and other additional space (e.g., load and unload acces, material handling carrier clearance) and add the separate quantities to determine the total space required (the preffered method of determining extra space)

Space Requirements

Space Requirements

65

Workstation

Aisle Allowance

Departmental Service

Aisle Widths

Visual Management

Documents

Product, Process and Schedule Design.ppt