chapter 5.pdf

Ch 5 : Plant Layout
Prepared By –
Ms. H.N.DAVE
Lecturer (Mechanical Engg. Dept.)
R.C. Technical Institute, Ahmedabad
hndrctimech@gmail.com

Plant/Facility Layout
Page 2
“Plant layout ideally involves allocation of space and
arrangement of equipment in such a manner that overall
operating costs are minimized.
Plant Layout is the physical arrangement of equipment and
facilities within a plant.
Plant layout refers to the arrangement of physical facilities
such as machinery, equipment, furniture etc. with in the
factory building in such a manner so as to have quickest
flow of material at the lowest cost and with the least
amount of handling in processing the product from the
receipt of material to the shipment of the finished product.

Objectives of plant layout
Provide overall satisfactionand simplification
Reduce material handling
Provide higher turn over i.e. increased production
Effective utilization of space
Worker convenience and job satisfaction
Labour utilization

Features of Plant Layout
Page 4
Provide space for machine / materials / storage / etc.
•Flexible for future changes in capacity / Design / Process etc
( Cellular design).
•Accommodate future expansion.
•Deals with government rules & regulations ( Municipal
corporation / Labor law & rules.
• Safety of employees / visitors / vendors is prime concern
• Achieve economy in operation.

• PRINCIPLE OF MINIMUM MOVEMENT
• PRINCIPLE OF FLOW
• PRINCIPLE OF SPACE
• PRINCIPLE OF SAFETY
• PRINCIPLE OF FLEXIBILITY
• PRINCIPLE OF INTERDEPENDENCE
• PRINCIPLE OF OVERALL INTEGRATION
• PRINCIPLE OF MINIMUM INVESTMENT
Page 5
Principles of Plant Layout

• PRINCIPLE OF MINIMUM MOVEMENT - As far as possible materials
and labour should be moved over minimum distances.
• PRINCIPLE OF FLOW - The work areas should be arranged according
to the sequence of operations so that there is continuous flow of
materials without congestion. The layout should allow for easy
movement of materials without interruption or delay.
• PRINCIPLE OF SPACE - All available cubic space should be effectively
used both vertically and horizontally.
• PRINCIPLE OF SAFETY - There should be consideration for safety and
convenience of workers. There should be built in provision for the
safety and comfort.
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• PRINCIPLE OF FLEXIBILITY - Layout should be designed in the
manner that production facilities can easily be rearranged when it
becomes necessary in future on account of expansion and
technological advancement.
• PRINCIPLE OF INTERDEPENDENCE Interdependent operations and
processes should be located in close proximity to each other.
• PRINCIPLE OF OVERALL INTEGRATION - All the plant facilities and
services should be fully integrated into a single operating unit so as
to maximize efficiency and minimize costs of production.
• PRINCIPLE OF MINIMUM INVESTMENT - The layout should yield
savings in fixed capital investment through optimum utilization of
available facilities.
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Factors affecting Plant Layout
Page 9
PLANT
LAYOUT
MAN
MATERIAL
MACHIN
E
MOVEME
NT
WAITING
SERVICE
BUILDIN
G
CHANGE

1) Building & Structure :Depend on type of production
system
( Intermittent / Continuous)
Intermittent System : Building & Shades are constructed
& layouts done in shades with best possible options &
then machinery will be brought inside.
Continuous System : Arrange machines first then construction
around .
It should withstand & offer support to cranes / hoists /
trolleys etc.
2) Men :
• Number of people.
• Unskilled ( More space ) / Skilled ( Less space i.e. Computer
operator).
• Physic of workers ( ex. height ).

3)Machinery :
Type of machine :
• General purpose machines : Compact in size & requires
less space.
• Special Purpose machines (SPM) : Large in size ,
complicated,
high level of automation.
• Number of machines :
• Level of automation ( Semi / fully automated)
• Higher complexity wider space.

• Nature of material ( Flammable / inflammable / Hazardous & Non
Hazardous , Corrosive , Methalene , mercury , oils , fuels)
• Form of material ( Solid / Liquid / Powder etc)
• Quantity of material to be handled.
• Cycle Time : Consumption of material.
3) MATERIAL :

5) Movement :
• Movement of people / machines / cranes ( length & frequency)
• Purpose of movement ( With load / without load / Quantity ofload)
6)Waiting Time :
• Cycle time for completeting each activity.
• Intermittent –
• Uncertain & High.
• More storage places between machines & facilities.
• Continuous –
• Defined & low.

Changes :
• Production Volume
• Product type & design
• Process type
• Varieties
• Frequency of change ( Ex 5 years)
Services:
• Electrical supply
• Pneumatic supply ( Air supply)
• Water supply
• Chilling process – Cooling Tower
• Air ventilation –Ducting
• Fire extinguishers – Water
sprinklers

• Factory building - The nature and size of the building determines the floor space
available for layout. While designing the special requirements, e.g. air
conditioning, dust control, humidity control etc. must be kept in mind. Location
of a plant greatly influences the layout of the plant. Topography, shape, climate
conditions, and size of the site selected will influence the general arrangement of
the layout and the flow of work in and out of the building.
• Nature of product - Production of heavy and bulky items need different layout as
compared to small and light items. Similarly products with complex and
dangerous operations would require isolation instead of integration of processes.
• 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 that dangerous fumes can be removed through proper
ventilation etc. Adequate safety arrangement should also be made.
• Repairs and maintenance - Machines should be so arranged that adequate space
is available between them for movement of equipment and people required for
repairing the machines.
Page 15

• Management policy - Various managerial policies relate to future volume of
production and expansion, size of the plant, integration of production processes;
facilities to employees, sales and marketing policies and purchasing policies etc.
These policies and plans have positive impact in deciding plant layout.
• Human needs - Adequate arrangement should be made for cloakroom,
washroom, lockers, drinking water, toilets and other employee facilities, proper
provision should be made for disposal of effluents, if any.
• Type of machinery - General purpose machines are often arranged as per process
layout while special purpose machines are arranged according to product layout.
• Production Process - In assembly line industries, product layout is better. In job
order or intermittent manufacturing on the other hand, process layout is
desirable.
Page 16

• Costs of movement of materials from one work area to another
• Cost of space
• Cost of production delays
• Cost of spoilage of materials
• Cost of labour dissatisfaction and health risks
• Costs of changes required if the operational conditions change in
the future.
• Cost of customer dissatisfaction due to poor service (quality,
delivery, flexibility, responsiveness, cost) which may be due to poor
layout.
Page 17
Costs involved

The production process normally determines the type of plant
layout to be applied to the facility:
• Fixed position plant layout
Product stays and resources move to it.
• Product oriented plant layout
Machinery and Materials are placed following the
product path.
• Process oriented plant layout (Functional Layout).
Machinery is placed according to what they do and
materials go to them.
• Combined Layout
Combine aspects of both process and product layouts
Page 19

Under this, machines and equipments are arranged in one line
depending upon the sequence of operations required for the product.
The materials move from 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.
Page 20

Product Layouts
• Product layouts are used to achieve a smooth and rapid flow of large volumes
of goods or customers through a system. Product layout sets up production
equipment along a product-flow line, and the work in process moves along this
line past workstations. It efficiently produces large numbers of similar items.
Page 21
14

 e.g. in a paper mill, bamboos are fed into the machine at one end and paper
comes out at the other end. The raw material moves very fast from one
workstation to other stations with a minimum work in progress storage and
material handling.
 e.g. chemicals, sugar, paper, rubber, refineries, cement, automobiles, food
processing and electronics etc.
Page 22
Product Layouts

Advantages
Page 23
 A high rate of output
 Low unit cost due to high volume
 Low material-handling cost per unit
 A high utilization of labor and equipment
 Smooth and uninterrupted operations
 Continuous flow of work
 Optimum use of floor space
 Shorter processing time or quicker
output
 Less congestion of work in the process
 Simple and effective inspection of work
and simplified production control
Disadvantages
 Morale problems due to repetitive stress
injuries.
 Highly susceptible to shutdowns
 Preventive maintenance, the capacity for
quick repairs, and spare-parts inventories
are necessary expenses
 High initial capital investment in special
purpose machine
 Breakdown of one machine will hamper
the whole production process
 Lesser flexibility as specially laid out for
particular product.
Product Layouts

• Process layout groups machinery and
equipment according to their functions.
• In this type of layout machines of a
similar type are arranged together at one
place. E.g. Machines performing drilling
operations are arranged in the drilling
department, machines performing
casting operations be grouped in the
casting department. Therefore the
machines are installed in the plants,
which follow the process layout.
Page 24

Process Layouts
• Process layouts are designed to process items or provide services
that involve a variety of processing requirements.
Page 18
25

Process Layouts
The grouping of machines according to the process has to be done
keeping in mind the following principles –
1. The distance between departments should be as short as possible for
avoiding long distance movement of materials.
2. The departments should be in sequence of operations
3. The arrangement should be convenient for inspection and supervision
e.g. tailoring, light and heavy engineering products, made to order
furniture industries, jewelry.
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26

Advantages
Page 27
 There is high degree of machine utilization, as a
machine is not blocked for a single product
 Change in output design and volume can be
more easily adapted to the output of variety of
products
 Not vulnerable to equipment failures.
Breakdown of one machine does not result in
complete work stoppage
 Supervision can be more effective and
specialized
 There is a greater flexibility of scope for
expansion
Disadvantages
 In-process inventory costs can
be high
 Material handling costs are high
 More skilled labour is required
resulting in higher cost.
 Time gap or lag in production is
higher
 Work in progress inventory is
high needing greater storage
space
 More frequent inspection is
needed which results in costly
supervision
Process Layouts

• A fixed-position layout places the product in one spot, and workers,
materials, and equipment come to it.
• In this type of layout, the major product being produced is fixed at one
location. Equipment labour and components are moved to that location.
All facilities are brought and arranged around one work center. This type
of layout is not relevant for small scale entrepreneur. E.g. - shipbuilding
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Fixed-Position Layouts
Page 29
22
• In fixed-position layouts, the item being worked on remains
stationary, and workers, materials, and equipment are moved
about as needed.
• Fixed-position layouts are widely used in farming, firefighting,
road building, home building, remodeling and repair, and
drilling for oil. In each case, compelling reasons bring workers,
materials, and equipment to the “product’s” location instead
of the other way around.
• Manufacture of bulky and heavy products such as locomotives,
ships, boilers, generators, wagon building, aircraft
manufacturing, etc. Construction of building, flyovers, dams.

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Advantages
 Saves time and cost in movement
 Flexible as changes in job design can be
easily incorporated
 More economical when several orders in
different stages are executed
 Adjustments can be made to meet
shortage of materials or absence of
workers.
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Disadvantages
• Capital investment is quite heavy
• Very large space is required for storage
of materials and equipment
• As several operations are carried
simultaneously, possibility of confusion
and conflicts are high

• Customer-oriented layout arranges facilities to enhance the interactions
between customers and a service.

Combination Layouts
• Combine aspects of both process and product layouts.
• Supermarket layouts are essentially process layouts, yet we find
that most use fixed-path material-handling devices such as roller-
type conveyors in the stockroom and belt-type conveyors at the
cash registers.
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