Unit 4 Manufacturing system design

MATERIAL HANDLING
FUNCTION
 The development of material handling system to move materials from one stage of
production to another is very important.
 Materials handling includes moving, packaging, and storing all the materials used by
the production unit.
 Materials handling is one of the important activities in materials management and
also in production.
 Materials are received by rail or truck. It is moved into the plant and thereafter to the
storeroom. When material is needed, it is moved along the path of assembly.
 Plant layout and materials handling are closely inter-related. This statement is true as
materials handling activity needs to be adjusted as per the layout of the plant.

Contd…
• Material handling. ... It utilizes a wide range of manual, semi-
automated, and automated equipment and includes consideration of
the protection, storage, and control ofmaterials throughout their
manufacturing, warehousing, distribution, consumption, and disposal.
Role of material handling:
Material handling plays an important role in manufacturing and logistics,
which together represent over 20% of the U.S. economy. Almost every
item of physical commerce was transported on a conveyor or lift truck or
other type of material handling equipment in manufacturing plants,
warehouses, and retail stores.

Contd…
Types of material handling:
Manual handling
Automated handling
Manual handling:
Manual handling refers to the use of a worker’s hands to move
individual containers by lifting, lowering, filling, emptying, or
carrying them. It can expose workers to physical conditions that
can lead to injuries that represent a large percentage of the over
half a million cases of musculoskeletal disorders reported in the
U.S. each year, and often involve strains and sprains to the lower
back, shoulders, and upper limbs

Contd….
Automated handling:
Whenever technically and economically feasible, equipment can be
used to reduce and sometimes replace the need to manually handle
material.
 Most existing material handling equipment is only semi-
automated because a human operator is needed for tasks like
loading/unloading and driving that are difficult and/or too costly to
fully automate, although ongoing advances in sensing, machine
intelligence, and robotics have made it possible to fully automate an
increasing number of handling tasks.

TYPES OF EQUIPMENT USED
Industrial Trucks:
 Industrial trucks are trucks that are not licensed to travel on public
roads
 Industrial trucks are used to move materials over variable paths and
when there is insufficient (or intermittent) flow volume such that the
use of a conveyor cannot be justified.
Conveyors:
 Conveyors are used when material is to be moved frequently
between specific points over a fixed path and when there is a
sufficient flow volume to justify the fixed conveyor investment.

Contd…
Cranes:
Cranes are used to transport loads over variable (horizontal and
vertical) paths within a restricted area and when there is insufficient
(or intermittent) flow volume such that the use of a conveyor cannot
be justified.
Cranes provide more flexibility in movement than conveyors because
the loads handled can be more varied with respect to their shape and
weight

Contd…
Automated guided vehicle:
An automated guided vehicle or automatic guided vehicle (AGV) is a
portable robot that follows markers or wires in the floor, or uses vision,
magnets, or lasers for navigation. They are most often used in industrial
applications to move materials around a manufacturing facility or
warehouse. Application of the automatic guided vehicle broadened
during the late 20th century.

CONVEYOR SYSTEMS
• A conveyor system is a common piece of mechanical handling
equipment that moves materials from one location to another.
Conveyors are especially useful in applications involving the
transportation of heavy or bulky materials.
• Conveyor systems allow quick and efficient transportation for a wide
variety of materials, which make them very popular in the material
handling and packaging industries.
• Many kinds of conveying systems are available and are used
according to the various needs of different industries.

Contd…..
Types of conveyor systems:
Conveyor belt:
A conveyor belt is the carrying medium of a belt conveyor system (often
shortened to belt conveyor). A belt conveyor system is one of many types
of conveyor systems. A belt conveyor system consists of two or more pulleys, with
an endless loop of carrying medium—the conveyor belt—that rotates about them.
One or both of the pulleys are powered, moving the belt and the material on the
belt forward.

Contd…
Chain conveyor:
Chain conveyors utilize a powered continuous chain arrangement, carrying a
series of single pendants.
The chain arrangement is driven by a motor, and the material suspended on the
pendants are conveyed.
 Chain conveyors are used for moving products down an assemble linen and/or
around a manufacturing or warehousing facility.
Chain conveyors are primarily used to transport heavy unit loads, e.g. pallets, grid
boxes, and industrial containers. These conveyors can be single or double chain
strand in configuration. The load is positioned on the chains, the friction pulls the
load forward. Chain conveyors are generally easy to install and have very
minimum maintenance for users.

Contd…
Screw conveyor:
A screw conveyor or auger conveyor is a mechanism that uses a rotating
helical screw blade, called a "flighting", usually within a tube, to move liquid or
granular materials.
They are used in many bulk handling industries. Screw conveyors in modern
industry are often used horizontally or at a slight incline as an efficient way to
move semi-solid materials, including food waste, wood chips, aggregates, cereal
grains, animal feed, boiler ash, meat and bone meal, municipal solid waste, and
many others.
The first type of screw conveyor was the Archimedes' screw, used since ancient
times to pump irrigation water.

Contd….
Vertical conveyor systems:
Vertical conveyor - also commonly referred to as freight lifts and
material lifts - are conveyor systems used to raise or lower materials
to different levels of a facility during the handling process.
 Examples of these conveyors applied in the industrial assembly
process include transporting materials to different floors.
While similar in look to freight elevators, vertical conveyors are not
equipped to transport people, only materials.

Contd..
Line shaft roller conveyor:
 A lines haft roller conveyor or line-shaft conveyor is, as its name
suggests, powered by a shaft beneath rollers. These conveyors are
suitable for light applications up to 50 kg such as cardboard boxes and
tote boxes.

“AUTOMATED GUIDED VEHICLES”

CONTENTS
• Introduction
• History of AGV’S
• What is AGV?
• Types of AGV’s
• Why consider AGV’s
• Types of navigations in AGV’s
• Applications of AGV’s

INTRODUCTION
• AGVs increase efficiency and reduce costs by helping to automate
a manufacturing facility or warehouse.
• AGVs can carry loads or tow objects behind them in trailers. The
trailers can be used to move raw materials or finished product. The
AGV can also store objects on a bed. some AGVs use fork lifts to lift
objects for storage. AGVs are employed in nearly every industry,
including, paper, metals, newspaper and general manufacturing

Continued…
• An AGV can also be called a laser guided vehicle(LGV) or self-guided
vehicle (SGV). In Germany the technology is also called Fahrerlose
Transport system (FTS) and in Sweden Forarlosa trucker.
• AGVs are available in a variety of models and can be used to move
products on an assembly line, transport goods throughout a plant or
warehouse.

History of AGV’S
• The first AGV was brought to market in the 1950s, by Barrett
Electronics of Northbrook, and at the time it was simply a tow truck
that followed a wire in the floor instead of a rail. over the years the
technology has become more sophisticated and today automated
vehicles are mainly Laser navigated ex: LGV.
• In an automated process, LGVs are programmed to communicate
with other robots to ensure product is moved smoothly through the
warehouse, whether it is being stored for future use or sent directly
to shipping areas. Today the AGV plays an important role in the design
of new factories and warehouses.

AGV?
• AGV is a material handling system that uses independently operated,
self-propelled vehicles guided along defined pathways.

COMPONENTS OF AGV
• Vehicle
• Guided path
• Control unit
• Computer interface

CarryBee(AGV)
Dolly type(D type)
1. Towing type
2. Loading type
Low height type
 Short type (S type)
 Mid-sized type (M type)
 Heavy-duty type (H type)
 Super low height type (L type)
 Super low speed type
 Low height towing (Kai)
Kit (K type)

Why consider AGVs?
• Reduces the labor cost.
• Flexible.
• Intelligent.
• Time consuming.
• Can significantly reduce production & warehouse costs.
• Transforming the materials handling industry.

TYPES OF NAVIGATION IN AGV’S
• Wired navigation
• Guide tape navigation
• Laser target navigation

WIRED NAVIGATION
• The wired sensor is placed on bottom of the AGV’S and is placed
facing the ground.
• A slot is cut in the ground and a wire is placed approximately 1 inch
below the ground.
• The sensors detects the radio frequency being transmitted from the
wire and follows it.

GUIDE TAPE NAVIGATION
• The AGV’S( some known as automated guided carts or AGC’S) use
magnetic tape for the guide path.
• The AGC’S is fitted with the appropriate guide sensors to follow the
path of the tape.
• It is considered a “passive” system since it does not require the guide
medium to be energized as wire does.

LASER TARGET NAVIGATION
• The AGV’S carry’s a laser transmitter and receiver on a rotating turret.
• The laser is sent off then received again the angle and distances are
automatically calculated and stored into AGV’S memory.
• The AGV’S has reflector map stored in memory and can correct its
position based on errors between the expected and received
measurements.
• It can then navigate to a destination target using the constantly
updating position.

LASER TARGET NAVIGATION AGV’S

COMMON AGV APPLICATIONS
Automated Guided Vehicles can be used in a wide variety of
applications to transport many different types of material including
pallets, rolls, racks, carts, and containers.
RAW MATERIAL HANDLING:
AGVs are commonly used to transport raw materials such as paper,
steel, rubber, metal, and plastic. This includes transporting materials
from receiving to the warehouse, and delivering materials directly to
production lines.

WORK-IN-PROCESS MOVEMENT:
Work-in-Process movement is one of the first applications where
automated guided vehicles were used, and includes the repetitive
movement of materials throughout the manufacturing process.
PALLET HANDLING:
Pallet handling is an extremely popular application for AGVs as
repetitive movement of pallets is very common in manufacturing and
distribution facilities.

FINISHED PRODUCT HANDLING:
Moving finished goods from
manufacturing to storage or shipping
is the final movement of materials before
they are delivered to customers.
These movements often require the
gentlest material handling because the
products are complete and subject to
damage from rough handling.

GUIDANCE SYSTEMS
What is a guidance system?
A guidance system is what directs the vehicle on the path it will
take to get from point “A” to point “B.” The decision about the type of
guidance system that will be used is one of the most crucial that will be
made. Some guidance systems have a high reliability and very rarely
fail, but these same guidance systems restrict the flexibility of the
factory.

TYPES OF GUIDANCE SYSTEM
• WIRE GUIDANCE
• OPTICAL GUIDANCE
• Spot Guidance
• Paint/Chemical Guidance
• LASER GUIDANCE
• INERTIAL GUIDANCE
• DEAD-RECKONING GUIDANCE SYSTEM
• BEACON GUIDANCE

WIRE GUIDANCE
Wire guidance is the most common
type of guidance system. It is known to be
reliable, but not very flexible. The wire that
carries an electric current is embedded in
concrete along the pre-determined path. The
groove that carries the guidance wire can
also be used to carry communication cables
so messages can be transmitted to the AGV
without the use of an RF modem.

OPTICAL GUIDANCE
• There are two basic types of optical guidance systems. The first
is spot guidance system that uses spots of reflective material on the
ground to guide the vehicle.
• The second system is the painted line guidance system that uses
a paint or chemical path for guidance.

SPOT GUIDANCE
• A spot guidance system uses lights on the bottom of the vehicle
such as halogen lamps.
• This light is reflected off reflective spots on the floor such as a
small glass beads to a camera or other sensor on the bottom of the
vehicle.
• Different shapes of glass bead can have different meanings to the
vehicle such as: Stop, turn left, turn right, etc.

PAINT/CHEMICAL GUIDANCE
• This type of system uses a line of fluorescent particles or dye to
indicate the path for the vehicle to follow.
• Once again, sensors on the vehicle are used to detect reflected
light to indicate to the vehicle its position in relation to the specified
path.
• Information codes can also be set on the path and the sensor will
“read” the codes and perform the action instructed by the code such
as: Stop, turn left, slow down, etc.

LASER GUIDANCE
Laser guidance using
reflective targets and a laser
scanner, the exact location of the
AGV can be calculated. Unlike the
wire guided and optical systems,
“a laser guidance system does not
rely on floor-based reference
points”. The targets are mounted
on the wall and are scanned by
the scanner on the AGV.

INERTIAL GUIDANCE
The inertial guidance system is
different from any of the other guidance
systems previously discussed. The
inertial guidance system uses a
gyroscope to determine the direction
the AGV is moving. The vehicle can be
programmed to take a variety of courses
without additional costs due to moving
wire or setting up new “targets.”

DEAD-RECKONING GUIDANCE SYSTEM
• Dead-reckoning refers to another non-wire system. This system
uses an optical encoder on the drive wheels to measure rotation and
steer angle.
• A controller is used to calculate the position of the AGV based on
the starting position, the internal map, and the information that is
provided by the optical encoder.
• The dead-reckoning guidance system adds flexibility over the
wire guided system or optical systems, but they require smooth
surfaces to run on

BEACON GUIDANCE
• The beacon guidance system operates on a concept similar to
that of the laser guidance system. In the beacon system, beacons are
placed in strategic locations around the plant. The AGV is
programmed with the exact location of these beacons.
• As with all of the other non-wire guidance systems, the beacon
system offers higher flexibility as compared to the wire guidance
system or optical systems

ROUTING OF AGVS
The routing of an AGVS defines the path the guidance system will
take based on a number of design factors from the number of vehicles
to be used to the amount of space available to run the AGV.
FLOOR SPACE
• The amount of floor space that is available restricts the number
of vehicles that can pass through an area at the same time.
• Floor space availability will affect the guide path due to some
areas having more obstructions or foot traffic than others will

ROUTING OF
AGVS
STATIC PATH
UNIDIRECTIONAL
SYSTEMS
BI-DIRECTIONAL
SYSTEMS
DYNAMIC PATH
flexible system

STATIC PATH
Static guide paths are used when every possible pick-up or drop-
off point is known. If these points are known, there will be a finite
number of routes that can be taken to get from one to the other.
Unidirectional Systems
Bi-directional Systems

UNIDIRECTIONAL SYSTEMS
• The vehicles are only allowed to travel in one direction. The vehicles
are given a single lane, and they travel in somewhat of a loop to and
from the destinations.
• . Even though AGVs are only allowed to travel a certain direction in a
given lane, if a particular aisle can support more than one lane, it can
still be unidirectional as long as each lane only has traffic proceeding
in one direction.

BI-DIRECTIONAL SYSTEMS
• A bi-directional system allows vehicles to use the same lane to travel
in either direction. “This functionality can be accomplished by
providing turnaround points for vehicles or by using bi-directional
vehicles…”
• Bi-directional systems do increase the complexity of dispatching due
to multiple vehicles going two directions on the same path, but as
previously noted, there are some benefits to it.

DYNAMIC PATH
• A dynamic path system is not typically used in the industrial
environment. In this type of system, the vehicle must have a map of
the area.
• Once it receives its next location, it plots its own course, and uses
ultrasonics or other sensors to avoid collisions.
• . This is an extremely flexible system because there are no beacons to
set, not target to hit, and no wires to follow.

WORK ZONE
TRAFFIC CONTROL & SAFETY

WORK ZONE TRAFFIC CONTROL
• Influences drivers’ perception of risk
• Provides information on potential hazards
• Minimizes aggressive behavior
• Assists in navigation
• Engineering concerns for work zones
• Primary focus: Safe and efficient movement of
vehicles through work zone
• Relatively less emphasis on safety of construction
workers

TYPE OF BARRIER
• Rigid Barriers
• Provide separation between
• Opposing traffic lanes
• Traffic lanes and work area
• Cause damage to motorists if struck
Concrete barrier
separating
opposing traffic
Concrete barrier
separating traffic
lanes and work area

TYPE OF BARRIER
• Flexible barriers (channelizing devices)
– Provide nominal protection for workers
– Flexible and deformable, do not cause damage if
struck
Flexible barrier
separating traffic
lanes and work area
Channelizing devices
for delineation
Concrete barriers to
separate work area

• Advanced Warning Area
• Transition Area
• Activity Area
• Work space
• Traffic space
• Buffer space
• Termination Area
COMPONENTS OF TEMPORARY
TRAFFIC CONTROL ZONES(Source: MUTCD 2003)

WORKER SAFETY CONSIDERATIONS
IN WORK ZONE TRAFFIC CONTROL
• Modifying traffic control strategies to influence drivers’
perception of risk
• Leads to more careful and slower driving
• Improves safety for the workers
• Examples:
• Providing active warning devices
• Illuminated arrow boards
• Reliable advisory speed limit
• Active message with flashers
• Narrower lane widths
• Longer and/or wider buffer zones

TYPES OF TTC APPLICATIONS
• Each TTC zone is different
• Many variables affect the needs of each zone:
• Location of work
• Duration of work
• Highway type
• Geometrics
• Vertical and horizontal alignment,
intersections, interchanges, etc.
• Road user volumes
• Road vehicle mix (buses, trucks, and cars)
and road user speeds

WORK DURATION
• Major factor in determining the number and types of devices
used in TTC zones
• As per the MUTCD, five categories of work duration are
defined:
• Long-term stationary is work that occupies a location more
than 3 days
• Intermediate-term stationary is work that occupies a
location more than one daylight period up to 3 days, or
nighttime work lasting more than 1 hour
• Short-term stationary is daytime work that occupies a
location for more than 1 hour within a single daylight
period
• Short duration is work that occupies a location up to 1 hour
• Mobile is work that moves intermittently or continuously.

MOBILE WORK
• Often involve frequent short stops for activities
• Such as litter cleanup, pothole patching, or utility operations, and
are similar to short-duration operations
• TTC zones may includes:
• Warning signs, high-intensity rotating, flashing, oscillating, or
strobe lights on a vehicle, flags, and/or channelizing devices
• Flaggers
• A shadow vehicle equipped with an arrow panel or a sign
following the work vehicle
• Appropriately colored and marked vehicles with signs, flags, high-
intensity rotating, flashing, oscillating, or strobe lights, truck-
mounted attenuators, and arrow panels or portable changeable
message signs may follow a train of moving work vehicles

• Key elements that should be
considered to improve worker safety:
• Training
• Worker safety apparel
• Temporary traffic barriers
• Speed reduction measures
• Planning of activity area
• Planning for worker safety
WORKER SAFETY CONSIDERATIONS
Worker safety apparel

• All workers should be trained on:
• Working safely adjacent to vehicular traffic
• Work zone traffic control techniques
• Device Usage
• Safety devices
• Traffic control devices
• Placement of traffic control devices
• Relevant OSHA Regulation
• 29 CFR 1926.21, Safety Training and Education
WORKER SAFETY CONSIDERATION - TRAINING

• Workers near motor vehicle traffic should wear bright,
visible clothing
• Relevant OSHA Regulation
• 29 CFR 1926.95, Criteria for Personal Protective
Equipment
WORKER SAFETY CONSIDERATION-
WORKER SAFETY APPAREL

• Barriers shall be placed along the work zone
depending on:
• Lateral clearance of workers from adjacent
traffic
• Speed of traffic
• Duration and type of operations
• Time of day
• Volume of traffic
• Relevant OSHA Regulations
• 29 CFR 1926.200(g), Traffic Signs
• 29 CFR 1926.201, Signaling
• 29 CFR 1926.202, Barricades
WORKER SAFETY CONSIDERATION - TEMPORARY
TRAFFIC BARRIERS
Concrete Barriers

Speed of passing motorists may be
influenced by:
• Regulatory speed zoning
• Funneling
• Use of law enforcement
• Lane reduction
• Presence of flaggers
WORKER SAFETY CONSIDERATION –
SPEED REDUCTION MEASURES

• Plan internal work space and activities
• Minimize the use of backing maneuvers of construction
vehicles
• Minimize interactions between on-foot workers, equipment
and trucks
• Minimize worker exposure to risk
• Develop internal traffic control plan and operations
• Refer to “Module 2: Safe Operations and Internal Traffic
Control in the Work Space”
PLANNING THE ACTIVITY AREA

• Hazard assessment should be conducted based on:
• Characteristics of work site
• Job classifications required in the work area
• Must comply with all relevant OSHA regulations
• Assess worker risk exposures for each job site and job
classification
• 29 CFR 1926.20, General Safety and Health Provisions
• 29 CFR 1926.20 (b) (2)
PLANNING FOR WORKER SAFETY

• Common for mobile and constantly moving
operations
OPTIONAL WORKER SAFETY ELEMENTS-
SHADOW VEHICLE
Shadow vehicle with rear
mounted crash attenuator
• Should be equipped with:
– Appropriate lights
– Warning signs
– Rear-mounted impact
attenuator

• Reduce worker vulnerability to
risk of injury
• Provide more spacious areas to
conduct work activities
• Eliminate threat of intruding
vehicles from passing traffic
• Aid in faster project
completion
OPTIONAL WORKER SAFETY ELEMENTS -
ROAD CLOSURE
Freeway closure for one
direction of traffic

SAMPLE WORK ZONE TRAFFIC
CONTROL LAYOUT
• For a Single Lane Closure as per MUTCD
– Pre-construction speed limit is 70 mph
Channelizing Devices
KEY
Sign Location
Note: Distance in feet,
drawing not to scale
W21-4 W20-5 R2-5b W4-2R R2-1 G20-2
REDUCED
SPEED
XX
AHEAD
REDUCED
SPEED
XX
AHEAD
REDUCED
SPEED
XX
AHEAD
XX
AHEAD XX
SPEED
LIMIT
XX
SPEED
LIMIT
SPEED
LIMIT
1400’ 700’ 600’700’700’700’ 700’
Flashing
Arrow Panel
Median
REDUCED
SPEED
XX
AHEAD
REDUCED
SPEED
XX
AHEAD
REDUCED
SPEED
XX
AHEAD
XX
AHEAD XX
SPEED
LIMIT
XX
SPEED
LIMIT
SPEED
LIMIT

WORK ZONE TRAFFIC CONTROL
• MUTCD provides minimum requirements
• Various demanding situations may warrant enhanced
safety precautions, such as:
• Nighttime work
• Inclement weather conditions
• Unusual roadway geometry and environment
• Combinations of the above
• Going beyond existing standards/guidelines may be
necessary to ensure highest levels of traffic and worker
safety

HAZARDS OF WORK ZONE TRAFFIC
CONTROL
• Passing motorist intruding into the work space
• Hazards related to flagging
• Nighttime hazards
COMMON HAZARDS

HAZARDS OF WORK ZONE TRAFFIC CONTROL
• Conditions unexpected by the moving traffic
• Violation of driver expectancy
• Conditions unexpected by the workers
• Aggressive drivers
• Unplanned work zone/activity
• Injuries can occur due to
• Motorists’ mistakes
• Workers’ mistakes
• Deficiencies in the work zone environment
CAUSAL FACTORS

• Traffic Control
• Use additional
warning devices
• Maintain signs
properly
• Use Proper lane
markings
GENERAL PREVENTIVE MEASURES
• Flaggers
– Use a flashing
slow/stop
paddle
• On-foot workers
– Use portable radio
communication
equipment
• Law enforcement
– Use officers and radar
surveillance for traffic
speed control

• Hazard mitigation measures
• Use of proper speed reduction methods
• Proper design of the wok zone
• Provide effective traffic control measures
• Causes of Hazards
– High approach speed
– Improper geometry of the lane
shift
– Improper traffic control
– Inadequate information system
No physical separation between
work space and traffic lane
HAZARD: PASSING MOTORISTS
INTRUDING INTO WORK SPACE

SAMPLE WORK ZONE TRAFFIC CONTROL LAYOUT
WITH ADDITIONAL SAFETY FEATURES
• For a Single Lane Closure
Truck Mounted
Attenuator
W21-4 W20-5 R2-5b W4-2R R2-1
REDUCED
SPEED
XX
AHEAD
REDUCED
SPEED
XX
AHEAD
REDUCED
SPEED
XX
AHEAD
XX
AHEAD XX
SPEED
LIMIT
XX
SPEED
LIMIT
SPEED
LIMIT
D D
G20-2
D
G20-2
DDDD L
XX
Your
Speed is
XX
Your
Speed isWhite Pavement
Markings Symbol
Retroreflective Raised
Pavement Markers
Increase Buffer
Area
Radar Triggered
Speed Display
Temporary Rumble
Strips
Flashing
Arrow Panel
KEY :
Sign Location
D
L Length of Longitudinal Buffer Space
Distance Between Traffic Control Devices
KEY :
Sign Location
D
L Length of Longitudinal Buffer Space
Distance Between Traffic Control Devices

VERTICAL SAFETYCADE
• Designed to replace standard channelizing devices
• Benefits:
• Better visibility
• More positive guidance
• Greater portability
• Improved recoverability
• Collapsible frame
Vertical Safetycades

CB WIZARD ALERT SYSTEM
• Trailer-mounted system
• Broadcasts a recorded message
to all CB-equipped motorists
• Notify drivers of downstream
work zones
• Allows truck drivers to lower
their speeds in advance of
work zone
CB Wizard
Advanced
Warning Unit
CB Wizard Unit

RADAR-TRIGGERED SPEED DISPLAY
• Back-lit dynamic speed display
• Standard speed limit sign
• Strobe flash (optional)
• Strobe will flash when a
vehicle exceeds a certain
speed
• Trailer mounted

LANE DROP ARROWS
• Alert driver in advance
of lane closure
• Encourage drivers to
reduce speed and move
to the open lane

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UNIT IV
MATERIAL FLOW PATH
ANALYSIS IN
MANUFACTURING

MATERIAL HANDLING: PRINCIPLES &
EQUIPMENT DESCRIPTION
Definition of Material Handling:
“ Material Handling embraces all of the basic operations involve
in movement of bulk, packaged, & individual products in
semisolid or solid state by means of machinery, & within the
limits of place of business”
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OBJECTIVE OF MH
1. To increase efficiency of material flow by ensuring availability
of materials when & where they needed
2. To reduce MH cost
3. To improve facilities utilization
4. To improve safety & working conditions
5. To facilitate mfg processes
6. To increase productivity
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AUTOMATED STORAGE AND RETRIEVAL SYSTEMS (AS/RS)
To get right parts, pallets, fixtures, and tools to the right place at the right time, an efficient system for
their storage and retrieval together with a material transportation system is required.
An integrated FMS, AGVS, and AS/RS system provides an efficient production system for
manufacturing low- to medium- volume and middle- to high-variety products.
INTERFACING HANDLING AND STORAGE WITH
MANUFACTURING

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Function of storage systems and definition of AS/RS
Receiving, identification and sorting, dispatching to storage, placing in storage, storage,
retrieving from storage, order accumulation, packing, shipping, and record keeping for raw
materials, purchased parts, work in process, finished product, pallets, fixtures, tools, spare parts,
rework and scrap, office supplies, and so forth have traditionally been considered the functions of
storage systems.
An AS/RS attempts to achieve these functions by automating most of these procedures in a
cost-effective and efficient manner.

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AS/RS components and terminology used
An automated storage and retrieval system comprises the following:
1. A series of storage aisles having storage racks.
2. Storage and retrieval (S/R) machines, normally one machine per aisle, to store and
retrieve materials.
3. One or more pickup and delivery stations where materials are delivered for entry to the
system and materials are picked up from the system.

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Why an AS/RS?
An AS/RS is highly space efficient. Space now occupied by raw stock, work in process, or
finished parts and assemblies can be released for valuable manufacturing space.
Increased storage capacity to meet long-range plans.
Improved inventory management and control.
Quick response time to locate, store, and retrieve items.
Improved stock rotation.
Improved security and reduced pilferage because of closed storage area.
Flexibility in design to accommodate a wide variety of loads.

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Type of AS/RS
1. Unit load AS/RS: is used to store and retrieve loads that are palletized or stored in
standard-size containers.
2. Mini-load AS/RS: is designed to handle small loads such as individual parts, tools,
and supplies. The system is suitable for use where there is a limit on the amount of
space that can be utilized and where the volume is too low for a full-scale unit load
system and tool high for a manual system.
3. Person-on-board AS/RS: allows storage of items in less than unit load quantities.
4. Deep-lane AS/RS: The items are stored in multi-deep storage with up to 10 items per
row rather than single or double deep. This leads to a high density of stored items.
5. Automated item retrieval system

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Design of an AS/RS
1. Determining load sizes
2. Determining the dimensions of an individual storage space
3. Determining the number of storage spaces considering
Dedicated storage
Randomized storage
4. Determining the system throughput and number of S/R machines
Speed of S/R machine
Mix of single- and dual-cycle transaction
5. Determining the size parameters of the storage and retrieval system
6. Determining single- and dual-command cycle times for unit load AS
7. Determining utilization of S/R machine

UNIT LOAD CONCEPT
Unit Load:
“ It is defined as number of items arranged such that they can be
handled as a single object”
Unit load can be accomplished by:
1. Palletization: It is assembling & Securing of individual items on
a platform that can be moved by a truck or a crane
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Palllet
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UNIT LOAD CONCEPT (Cont..)
2. Unitization: It is also the assembling of goods, but as one compact
load. Unlike Palletization additional materials are used for packaging &
wrapping the items as a complete unit
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3. Containerization: It is assembling of items in a box or a bin. It
is most suitable for use with conveyors, especially for small
items
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• In general, the factors that influence the solution of the unit load
type are the weight, size, & shape of the material; compatibility
with the material handling equipment; cost of the unit load; &
the additional functions provided by the unit load stacking &
protection of material.
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MATERIAL HANDLING SYSTEM DESIGN
• Assuming there is a layout plan on hand, the steps to be followed in
designing a material handling system:
– State the intended function of the handling system; whether it is for a warehouse.
– Collect the necessary data about the material, such as its characteristics and the quantities involved.
– Identify the moves, their origin and destination, their path, and their length.
– Determine the basic handling system to be used and the degree of mechanization desired.
– Perform an initial screening of suitable equipment and select a set of candidate equipment among them.
Evaluate the candidate equipment on the basis of such measures as cost and utilization. Always match the
equipment with the material characteristics.
– Select a set of suitable unit loads and match them with material and equipment characteristics.

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Important factors that influence the designer in making decisions at each step of designing
process:
– Costs of equipment and unit loads and availability of funds. This will affect the degree of
mechanization to be achieved in the design.
– Physical characteristics of the building and the available space. Aisle width and number will be
affected by the available space, which in turn will influence decisions regarding mobile equipment.
Overhead equipment may or may not be considered, depending on the height of the ceiling.
– Management attitude toward safety and employee welfare, which will affect the degree of involvement
of material handling personnel in manual handling.
– Degree of involvement between handling and processing.
• During the design process, the objectives and the principles of MH
should be kept in mind. Achieving as many of the objectives and
principles as possible will result in a satisfactory and efficient design.

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To analyze an existing MH system is to determine whether it is functioning
efficiently without creating any bottlenecks or excessive inventories and is transporting the units
when and where needed.
The problems in an existing MH system will be evident if one can observe one or more of the
following symptoms in the system:
•Excess manual effort, •Excess walking,
•Failure to use gravity, •Fragmented operations,
•High indirect labor costs, •Idle machines,
•Inefficient use of skilled worker, •Lack of cube storage,
•Lack of parts, •Lack of supplies,
•Long hauls, •Material piled up on the floor,
•No standardization, •Poor inventory control,
•Product damage, •Repetitive handling,
•Service areas not conveniently located, •Truck delayed or tiled up,
It is also a good idea to examine the entire material handling system in the plant with a checklist
and identify the problems.

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Once the problem areas have been identified, they must be re-examined for possible
improvements. In performing such a study, some basic questions must be asked, such as:
Why? What? Where? When? How? Who?
• Liberal use of the question “Why?” is essential to separate what must be from what has
been; asking what and why defines the correct materials to be handled; asking
where, when, and why identifies the necessary moves to be performed; asking how,
who, and why establishes the correct methods to be used; and asking which and
why yields the preferred design.

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Productivity ratios: used as indicators of the performance of a system.
– Material Handling-Labor Ratio,
The ratio should be less than 1, and a reasonable value would be less than 0.30 in a plant, while in
a warehouse a higher value should be accepted.
– Handling Equipment Utilization Ratio,
Ideally, the ratio should be close to 1.0; however, equipment breakdown, poor scheduling,
housekeeping, building geography can reduce the load movement.
– Storage Space Utilization Ratio,
If the storage areas (such as bins or racks) are only partially full, then the percent of utilization
should be estimated and included in the calculation.

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A value close to 1 indicates assignment of appropriate space for the storage activities.
– Aisle Space Percentage,
It should have a value between 0.10 and 0.15.
– Movement/Operation Ratio,
It indicates the amount of material handling performed. The moves involved may consist of material moved
from receiving, from storage to an operation and back to storage, and so on. A high value indicates room for
improvement.
Manufacturing Cycle Efficiency,
Time not spent in production could be caused by delays in material movement, poor scheduling, machine
failure, and storage limitation, among others. For increasing machine utilization, the delay should be
eliminated or at least minimized. The performance index should be observed over a time period for
consistency.

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– Damaged Loads Ratio,
It measures the quality performance of material handling personnel. Damage to the loads during
receiving, in-process movement, and shipping should be minimized.
– Energy Ratio,
It measures the efficiency of heating and cooling operations. Some of the ways in which it can
be improved are reducing heating or cooling of a portion of the warehouse in which there are no
workers, turning lights off when not needed, and using lights on moving vehicles rather than
permanent lighting.

Unit 4 Manufacturing system design

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