Plant Layout (Ch-3)

7/31/2019 Plant Layout (Ch-3)

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Chap 3 - Facility /Plant/FactoryLayout:

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Facility Layout

Introduction Objectives & Principles Factors Affecting Layout Selection and

Design Types of Plant Layout Product Layout Process Layout

Fixed position layout or static layout;

Combination layout or Hybrid layout



Definition

Plant layout refers to the arrangementof physical facilities such as machines,equipment, tools, furniture etc. in sucha manner so as to have quickest flowof material at the lowest cost and withthe least amount of handling in

processing the product from thereceipt of raw material to the deliveryof the final product.



Introduction

Facility layout means planning: for the location of all machines, utilities,

employee workstations, customer service

areas, material storage areas, aisles,restrooms, lunchrooms, internal walls,offices, and computer rooms

for the flow patterns of materials and

people around, into, and within buildings infrastructure services such as the

delivery of line communications, energy,and water and the removal of waste waterall make up basic utilities.



Locate All Areas In and AroundBuildings

Equipment

Work stations

Material storage Rest/break areas

Utilities

Eating areas Offices



Objectives

Proper and efficient utilization of available floor space.

Reduce material handling costs Provide ease of supervision and

control.

Allow easy maintenance of machinesand plant.



Objectives of Plant Layout Elimination of unnecessary

occupied areas.

Reduction of administrativeand indirect work. Improvement on control and

supervision. Better adjustment to changing

conditions. Better utilization of the

workforce, equipment andservices.

Reduction of material handling

activities and stock in process. Reduction on parts and quality

risks. Reduction on health risks and

increase on workers safety.

Economies in materials,facilitate manufacturing

process & handling of semi-finished & finishedgoods.

To provide adequate safetyto the workers from

accidents. To meet the quality &capacity requirements inthe most economicalmanner.

Provision of medicalfacilities & cafeteria atsuitable & convenient

places. To provide efficient

material handling system. .



Types of Layout

i. Process layout or functionallayout or job shop layout;

ii. Product layout or line processing layout or flow-

line layout;iii. Fixed position layout or

static layout;

iv. Combination layout or Hybrid layout.

v. Cellular or Group Layouy

ProductLayouts

Fixed

Position

Layouts

Mixed Layouts Process Layouts

QuantityQuantity

Number of Different ProductsNumber of Different Products



Manufacturing units

(a) Product or line layout: Under this, machines and equipments are arranged in

one line depending upon the sequence of operations

required for the product. The materials move form

one workstation to another sequentially without any

backtracking or deviation. Under this, machines are

grouped in one sequence. Therefore materials are fed

into the first machine and finished goods travel

automatically from machine to machine, the output of

one machine becoming input of the next.



Suitability: Product layout is usefulunder following conditions:

Mass production of standardized products Simple and repetitive manufacturing

process Operation time for different process ismore or less equal Reasonably stable demand for the

product Continuous supply of materials



Types of plant layout

Product layout-

Layout that uses standardized processingoperations to achieve smooth, rapid, high-volume flow

Here machines are arranged acc. To theneeds of product & in the same sequenceas the operations are necessary formanufacture. E.g. ‘back office’ of services

such as banks and insurancecompanies.



Product (Assembly Line)Layouts

Product layouts are used to achieve asmooth and rapid flow of large volumesof products or customers through a

system.A job is divided into a series of

standardized tasks, permittingspecialization of both labor and

equipment.The large volumes handled by thesesystems usually make it economical toinvest huge amount of money inequipment and job design.



Product (Assembly Line)Layouts…

For instance, if a portion of amanufacturing operation required thesequence of cutting, sanding, and

painting, the appropriate pieces of equipment would be arranged in thatsame sequence.

Operations are arranged in the

sequence required to make theproduct Product layouts achieve a high degree

of labor and equipment utilization.



Characteristics of ProductLayouts

Special-purposeequipment areused

Changeover isexpensive andlengthy

Material flow is

continuous

Material handlingequipment is fixed

Planning, schedulingand controlling

functions are relativelystraight-forward

Production time for aunit is relatively short

In-process inventory is

relatively low Little direct

supervision is required



Product or Line Layout

ProductA

ProductB

ProductC

Step 1

Step 1

Step 1

Step 2

Step 2

Step 2

Step 3

Step 3

Step 3

Step 4

Step 4

Step 4



Raw

materials

or customer

Finished

itemStation

2

Station

2Station

3

Station

3Station

4

Station

4

Material

and/or

labor

Station

1

Material

and/or

labor

Material

and/or

labor

Material

and/or

labor

Used for Repetitive or Continuous Processing

Product Layout



Drilling Grinding Milling Weilding

Planer

lathe

AssemblePaintInspectionQuality

In

Out

Workers

A U-Shaped Production Line



21

A U-Shaped Production Line

Advantage: more compact, increased communication

facilitating team work, minimize the material handling



Product oriented plant layout Advantages:

Reduced materialhandling activities.

Work In Processalmost eliminated.

Minimum

manufacturing time. Simplification of theproduction planningand control systems.

Tasks simplification. Labor specialization High utilization of

labor and equipment Short processing

time High rate of output

Disadvantages:

No flexibility inthe productionprocess.

High capitalinvestment.

Every workstationis critical to theprocess.- The lackof personnel orshut down of amachine stops thewhole process.

Monotonous work.

Require largecapital investment Creates dull,

repetitive jobs



2.Process oriented plant layout (FunctionalLayout)

Layout that can handle varied processingrequirements

Here all machines performing similar type of operations are grouped together at one locationin the process layout. Thus here facilities are

grouped together acc. To their functions.Personnel and equipment to perform the samefunction are allocated in the same area.

E.g. all drilling machines are located at oneplace known as drilling section.

The different items have to move from one area toanother one, according to the sequence of operationspreviously established



Process (Job Shop) Layouts Used when the operations system must

handle a wide variety of products in relativelysmall volumes (i.e., flexibility is necessary)

Designed to facilitate processing items orproviding services that present a variety of processing requirements.

The layouts include departments or otherfunctional groupings in which similar kinds of

activities are performed. A manufacturing example of a process layout

is the machine shop, which has separatedepartments for milling,grinding, drilling, and

so on.



Characteristics of ProcessLayouts

General-purpose equipment is used

Changeover is rapid

Material handling equipment is flexible

Operators are highly skilled

Technical supervision is required

Planning, scheduling and controllingfunctions are challenging

Production time is relatively long

In-process inventory is relatively high



26

Dept. A

Dept. B Dept. D

Dept. C

Dept. F

Dept. E

Used for Intermittent processing

Process Layout(functional)

Process Layout



Process layout-



Dept. AD DDD

Dept. BP p

P p

Dept. DG G

G G

Dept. CW WW W

Dept. F

A A

A A

Dept. EL LL L

Used for Intermittent processing Job Shop or Batch

Process Layout

ProductA

RM –A

RM-B

Product B



Manufacturing units

(b) Process or functional layout



30

Process Layout

Gearcutting

Mill Drill

Lathes

Grind

Heattreat

Assembly

111

333

222

444

222

111

444

111 33311112222

222

3333

111

444

111

3 3 3 3 3 3 3 3 3

4 4 4 4 4

3 3 3 3 3 3

2 2 2 2 2



Manufacturing units


Advantages: Process layout provides thefollowing benefits

a) Lower initial capital investment in machines and equipments. Thereis high degree of machine utilization, as a machine is not blocked for a

single product b) The overhead costs are relatively low c) Change in output design and volume can be more easily adapted to

the output of variety of products d) Breakdown of one machine does not result in complete work

stoppage

e) Supervision can be more effective and specialized f) There is a greater flexibility of scope for expansion.

Manufacturing units



Manufacturing units


Disadvantages: Product layout suffers from followingdrawbacks

a. Material handling costs are high due to backtracking b. More skilled Labour is required resulting in higher cost. c. Time gap or lag in production is higher d. Work in progress inventory is high needing greater storage space

e. More frequent inspection is needed which results in costly supervision

Suitability: Process layout is adopted when 1. Products are not standardized 2. Quantity produced is small 3. There are frequent changes in design and style of product 4. Job shop type of work is done 5. Machines are very expensive

Thus, process layout or functional layout is suitable for job order production involvingnon-repetitive processes and customer specifications and non standardized

products, e.g. tailoring, light and heavy engineering products, made to order

furniture industries, jewelry.

o r o o ro ro o



o r o o ro ro ofactors Product layout Process layout

1. nature Sequence of facilities Similar aregp2gether

2. Machines

utilization

Not to full capacity Better utilization

3. product standardized diversified

4. Processing time less more

5. Material handling less more

6. inventory High WIP Low WIP

7. breakdown Can’t tolerate Can tolerate

8. Productioncentre

simple complex

9.flexibilty low high

10. floor space Requires less more



(c) Fixed Position or Location Layout

In this type of layout, the major product being produced isfixed at one location. Equipment Labour and components aremoved to that location. All facilities are brought and arrangedaround one work center. This type of layout is not relevant for small scale entrepreneur. The following figure shows a fixed

position layout

Stationary layout- Layout in which the



Stationary layout- Layout in which theproduct or project remains stationary, andworkers, materials, and equipment are

moved as needed. E.g. construction of DAMS.

The product, because of its size and/or

weight, remains in one location andprocesses are brought to it.

Fi d P iti L t



Fixed-Position Layouts In fixed-position layouts, the item being

worked on remains stationary, andworkers, materials, and equipment aremoved as needed.

Fixed-position layouts are used in large

construction projects (buildings, powerplants, and dams), shipbuilding, andproduction of large aircraft and space

mission rockets. Fixed-position layouts are widely used for

farming, firefighting, road building, homebuilding, remodeling and repair, anddrillin for oil.



PRODUCT

MATERIAL

MATERIAL

LABOUR

LABOUR

COMPONENTS

COMPONENTS

•



Fixed Position Layout or Static Layout



Fixed Position Layoute.g. Shipbuilding




Advantages a) It saves time and cost involved on the movement

of work from one workstation to another.

b) The layout is flexible as change in job design andoperation sequence can be easily incorporated.

c) It is more economical when several orders indifferent stages of progress are being executed

simultaneously. d) Adjustments can be made to meet shortage of materials or absence of workers by changing thesequence of operations.





Disadvantages: Fixed position layout has the followingdrawbacks

Production period being very long, capital investment isvery heavy

Very large space is required for storage of material andequipment near the product.

As several operations are often carried out simultaneously,

there is possibility of confusion and conflicts amongdifferent workgroups.

Suitability: The fixed position layout is followed in followingconditions

Manufacture of bulky and heavy products such as

locomotives, ships, boilers, generators, wagon building,aircraft manufacturing, etc. Construction of building, flyovers, dams. Hospital, the medicines, doctors and nurses are taken to the

patient (product).



(d) Combined layout Certain manufacturing units may require all three processes namely

intermittent process (job shops), the continuous process (mass production shops) and the representative process combined process[i.e. miscellaneous shops]. In most of industries, only a productlayout or process layout or fixed location layout does not exist.Thus, in manufacturing concerns where several products are

produced in repeated numbers with no likelihood of continuous

production, combined layout is followed. Generally, a combinationof the product and process layout or other combination are found, in practice, e.g. for industries involving the fabrication of parts andassembly, fabrication tends to employ the process layout, while theassembly areas often employ the product layout. In tablet,manufacturing plant, the machinery manufacturing tablet is arrangedon the product line principle, but ancillary services such as Heating,Ventilation and Air-Conditioning (HVAC)heating, the power house, the water treatment plant etc. are arrangedon a functional basis.



Cellular Manufacturing (CM)Layouts

Cellular manufacturing is a type of layout in which machines are groupedinto what is referred to as a cell.

Groupings are determined by theoperations needed to perform work fora set of similar items, or partfamilies that require similarprocessing.



Cellular Manufacturing (CM)Layouts…

These relate to the grouping of equipmentand include faster processing time, lessmaterial handling, less work-in-process

inventory, and reduced setup time.

Used when the operations system musthandle a moderate variety of products in

moderate volumes



‘Cellular’ Plant Layout

L M

D G

M M

D G

L L

L G

ASSEMBLY

CELL 3

ASSEMBLY

CELL 2

ASSEMBLY

CELL 1

• AKA ‘Group Technology’

• Each cell manufactures products

belonging to a single family.

• Cells are autonomous manufacturing

units which can produce finished parts.

• Commonly applied to machined parts.

• Often single operators supervising CNC

machines in a cell, with robots for

materials handling.

• Productivity and quality maximised.

Throughput times and work in progresskept to a minimum.

• Flexible.

• Suited to products in batches and where

design changes often occur.



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Cellular Manufacturing Layout

-1111 -1111

222222222 - 2222

A s s e m b l y

3333333333 - 3333

44444444444444 - 4444

Lathe

Lathe

Mill

Mill

Mill

Mill

Drill

Drill

Drill

Heat

treat

Heat

treat

Heat

treat

Gear

cut

Gear

cut

Grind

Grind



Cellular Layout

Process (Functional)

LayoutProcess (Functional)

Layout Group (Cellular) LayoutGroup (Cellular) Layout

Similar resources placed

together

Resources to produce similar

products placed together

T T T

M

M M T

M

SG CG CG

SG

D D D

D

T T T CG CG

T T T SG SG

M M D D D

M M D D D

A cluster

or cell



P-Q Analysis

ProductLayouts

Fixed

Position

Layouts Mixed Layouts Process Layouts

QuantityQuantity

Number of Different ProductsNumber of Different Products

B i L t F t



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Basic Layout Formats

Group TechnologyLayout

Similar to cellular layout

Part Family W Part Family X

Part Family Y

Part Family Z

Assemble Y,W Assemble X,Z

FinalProduct



Cellular Manufacturing Layout or Group Technology Layout



51

Dimension Process Cellular

Number of movesbetween departments

many few

Travel distances longer shorter

Travel paths variable fixed

Job waiting times greater shorter

Amount of work inprocess

higher lower

Supervision difficulty higher lower

Scheduling complexity higher lower

Equipment utilization Lower? Higher?

Process vs. Cellular Layouts



Hybrid (mixed) Layouts

Actually, most manufacturing facilities usea combination of layout types.

An example of a hybrid layout is where

departments are arranged according to thetypes of processes but the products flowthrough on a product layout.



Hybrid (mixed) Layouts… For instance, supermarket layouts are

fundamentally of a process nature, andhowever we find most use fixed-pathmaterial-handling devices such as roller-type conveyors both in the stockroom andat checkouts, and belt-type conveyors atthe cash registers.

Hospitals also use the basic process

arrangement, although frequently patientcare involves more of a fixed-positionapproach, in which nurses, doctors,medicines, and special equipment are

brought to the patient.



Combined Layout or Hybrid Layout for Gear Manufacturing



LAYOUT

Factory building: The nature and size of the building determines the

floor space available for layout. While designing the specialrequirements, e.g. air conditioning, dust control, humidity controletc. must be kept in mind.

Nature of product: product layout is suitable for uniform productswhereas process layout is more appropriate for custom-made

products. Production process: In assembly line industries, product layout is better. In job order or intermittent manufacturing on the other hand, process layout is desirable.

Type of machinery: General purpose machines are often arranged as

per process layout while special purpose machines are arrangedaccording to product layout

FACTORS INFLUENCING



LAYOUT Repairs and maintenance: machines should be so arrangedthat adequate space is available between them for movementof equipment and people required for repairing the machines.

Human needs: Adequate arrangement should be made for cloakroom, washroom, lockers, drinking water, toilets andother employee facilities, proper provision should be madefor disposal of effluents, if any.

Plant environment: Heat, light, noise, ventilation and other aspects should be duly considered, e.g. paint shops and

plating section should be located in another hall so thatdangerous fumes can be removed through proper ventilationetc. Adequate safety arrangement should also be made.

Thus, the layout should be conducive to health and safety of employees. It should ensure free and efficient flow of menand materials. Future expansion and diversification may also

be considered while planning factory layout.

Plant Layout (Ch-3)

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