Warehouse Management System

WAREHOUSING MANAGEMENT SYSTEM
(WMS)

WMS
• WMS is group of computer programs designed to help
a distributor perform WH operations more quickly and
consistently with fewer errors employing wireless
technology (RF or wireless network based).
• WMS ranges in complexity from very basic tools to
assist WH employees in performing daily operations to
highly sophisticated systems that replace workers.
• Two Key Elements;
– Use of Portable Computer Terminals (connected to host
computer and could be RF or a Palm Pilot like device
operating over a wireless network) to record work
performed in real time.
– Bar Codes are used to reduce amount of information to be
entered directly into terminal. Each terminal contains a
scanner, to scan labels that contain a bar coded
representation of bin, item & lot numbers, quantities,
and more whenever possible to eliminate keystrokes.

WMS CAN PROVIDE AN ORGANIZATION
WITH TANGIBLE BENEFITS
• Improving WH operations and increasing
efficiencies without adding headcount.
• Directed put-away and directed order
picking
• WH capacity management
• RF capability for data capture
• Load planning
• Cross docking
• Picking optimization
• ABC stratification
• Interleaving of work

COMMON CAPABILITIES OF A WMS
Receiving Inventory
• Objective is to record the receipt of goods accurately.
• Operator records the receipt of goods against a pur/ Tfr
order, customer return authorization, or a kitting or
production work order in the simplest form of receiving
• Advanced capabilities include receiving against packing
list or advanced ship notice and receiving by container.
Locating Inventory (Referred to as Putaway)
• Process of moving received inventory from the dock,
kitting, or production department to a storage bin
• User Directed Putaway (simplest form of putaway):
where the operator determines where to place inventory
and uses portable terminal to record movement
• System Directed Putaway (advanced form of putaway):
WMS determines bin in which the inventory is to be stored
and directs operator to place inventory in assigned bin.

COMMON CAPABILITIES OF A WMS (contd)
Inventory allocation
• Process of determining the bin from which inventory is
to be picked to satisfy a demand
• Operator performs inventory allocation by choosing bin
from which to pick inventory from a list of available
bins shown on a pick list
• WMS performs inventory allocation when an order is
released for picking
Picking inventory to satisfy sales, transfer, kitting, or
production/rework orders
• Basically operator uses a printed pick list and records
the results on the portable terminal.
• There are quite a variety of picking methods including
pick by order, wave picking, pick and pass, and batch
picking .

Replenishment
• Process of refilling forward pick bins (sometimes called
dedicated or primary bins) for an item from reserve
inventory.
Shipping confirmation
• This function is often left in the enterprise software at
the most basic level
• Can be performed within the WMS or performed by
special shipping software that operates along with the
WMS or a combination of both.

Cycle counting and physical inventory
• In the most basic form the operator counts inventory
and records the results using the portable terminal.
• More advanced systems determine the number of counts
that need to be performed each day, determine which
items to count each day, assign items to count to a
queue, and guide the operator around the warehouse in
an efficient manner to perform the counts
WH operations
• such as relocating inventory and recording inventory
gains and losses (adjustments) – an operator generally
performs these activities as required and records the
results using a portable terminal

ADVANTAGES OF WMS
A WMS helps improve customer service and
resource utilization by eliminating errors. The
result of eliminating errors can be measured by;
– Inventory accuracy – greater than 99% at the
item and bin level.
– Zero returns due to warehouse errors
– Checking operations are eliminated
– Improved order shipment completion
– Shortened order lead time and improved on-time
delivery performance

TANGIBLE COSTS
CATEGORY REASONS
Inventory reduction of up to 10% (one-
time savings)
Inventory visibility and accuracy
Reduced inventory carrying costs up to
35% (industry average)
Lower inventory levels; higher space
utilization
Reduced investment based on cost of
money @ 8%
Reduced inventory
Premium shipping costs Reduced shipping errors
Personnel handling paper - potential
headcount reduction or resource
redeployment
WMS automates the management of
order and priorities, eliminating paper
Personnel handling order picking –
potential headcount reduction or resource
redeployment
RF based picking productivity increases
efficiencies
Personnel handling shipping paperwork
and confirmation - potential headcount
reduction or resource redeployment
Eliminate preparation work for shipping
documents and ERP ship confirmations

IS WMS REALLY NEEDED?
• Is the benefit great enough to justify the initial
and ongoing costs associated with WMS: big,
complex, data intensive, and applications?
• The Claims:
– WMS will reduce inventory!
– WMS will reduce labor costs!
– WMS will increase storage capacity!
– WMS will increase customer service!
– WMS will increase inventory accuracy!

IS WMS REALLY NEEDED: REALITY
• Expectations of inventory reduction and increased
storage capacity are less likely: increased accuracy and
efficiencies in receiving process may reduce level of safety
stock required, impact of this reduction will be negligible
in comparison to overall inventory levels.
• Lot sizing, lead times, and demand variability control
inventory levels: WMS not likely to have a significant
impact on any of these factors.
• WMS certainly provides tools for more organized storage
resulting in increased storage capacity, it shall be relative
to just how sloppy pre -WMS processes were.
• Determining factors to implement a WMS is associated
with the need to do something to service your customers
that your current system does not support (or does not
support well) such as FIFO, cross-docking, automated
pick replenishment, wave picking, lot tracking, yard

ABC INVENTORY CONTROL
• ABC analysis or Pareto's law is a
principle widely used for decision
making and control in many
areas of management.
• ABC analysis is the process of
dividing items in to three classes
according to their rupee value;

•
• Policies;
ITEMS Cont Records Order of Importance
A
Highest
Priority
Very
tight
Accurate •Only 20% of the items but
account for 80 % of rupee value
•Very important & high value for
an organization, thus frequent
value analysis is required.
B
Priority
when Low
or Out of
Stock
Less
tight
Good
records
•Account for 30% of the items
but 15% of rupee value
• Less important, than ‘A’
items and are intergroup items.
C
Lowest
Priority
Simp
lest
possi
Minimal
records
•50% of the items fall in this
representing a mere 5 % of the
rupee value.
• Items are marginally
important.

Managing Inventories by ABC:
• ABC analysis classifies items on basis of their relative
importance. Classification may be on the basis of;
– Monetary value,
– Availability of resources,
– Variations in lead-time,
– Part criticality to the running of a facility,
– arts unique to that product, and others.
Cycle inventory can be managed through ABC;
• “A” value items have to be counted more frequently ie, once
in a week to do accurate monitoring of these items which has
more impact on the inventory value.
• “B” value items can be counted once in a month being of
moderate value having less impact on inventory value.
• “C” items counted once in 3/6 months because they are
least consumed value items and has very less impact on
inventory value.

ABC INVENTORY CONTROL (contd)
Obsolescence budgeting
• “A” items have the most impact on the budget,
if it is determined to be obsolete and scrapped
from inventory.
Reorganization of the storeroom
• “A” parts should continually be moved to the
lower or easier access areas.
• ‘B” items are to be moved to middle areas, and
• “C” items placed in all other areas of stores.

PRINCIPLES AND PERFORMANCE
MEASURES OF
MATERIAL HANDLING SYSTEMS (MHS)

PRINCIPLES AND PERFORMANCE MEASURES
OF MATERIAL HANDLING SYSTEMS
• A performance measure may be defined as a metric for
quantifying efficiency and/ or effectiveness.
• Effectiveness of a MHS describes to what extent the
system performs the required handling tasks.
• Efficiency describes how economically (in terms of
resource utilization) these tasks are performed.
• Thus, it is possible for an effective system to be
inefficient; it is also possible for an efficient system to
be ineffective.

DESIGN & OPERATION OF MHS
• MHS in any manufacturing setting plays an important part in
the performance of the entire manufacturing system.
• Research in the design of MHS has primarily studied system
performance as a function of:
– Guide path design or layout
– Type of flow path
– Number of lanes in each aisle,
– Location of pick-up/delivery points,
– Fleet size,
– Unit load size,
– Vehicle speed and
– Queue capacity at each workstation.
• Research in the operation of these systems has primarily
studied performance as a function of
– Vehicle dispatching rules and scheduling,
– Idle vehicle positioning,
– Vehicle routeing, and
– Zone definitions.

CHARACTERISTICS OF EFFECTIVE
PERFORMANCE SYSTEMS
Performance measure selection is process of defining a set of
measures that possess certain characteristics, found in any
effective performance measurement system (PMS);
• Inclusiveness: PMS should measure all pertinent aspects of the
MHS. In this way, good performance of one particular component of
the system would not be possible without similar performance of
other system components.
• Universality: PMS should allow for comparison under a wide range
of operating conditions, ie if two competing MHS designs must be
compared, then PMS should allow for this comparison, even if
system characteristics differ significantly.
• Measurability: All data required by PMS should be readily
measurable. Furthermore, the process of measuring the performance
of MHS should occur with a minimum of measurement errors and at
a reasonable expense.
• Consistency: PMS Should be consistent with overall goals of org.
The value of performance measure should therefore provide
meaningful insights into overall MHS performance wrt org objectives.

PRINCIPLES & PERFORMANCE MEASURES OF MHS:
VEHICLE TRAVEL DISTANCE (VTD OR TRAVEL TIME)
• VT is measured as actual path and not rectilinear/ Euclidean
distances.
• Total VTD consists of loaded and empty vehicle travel.
• Material flow can then be characterized as either: departmental
(within deptt) or intra-deptt (between deptts).
• Material flow within deptt is usually not modelled in MHS analysis.
• Measurement of VT may include loaded /empty vehicle travel, or
both.
• VTD is easily calculated when the flow volumes (trips required per
unit time) and distances between stations are known.
• VT time directly corresponds to vehicle distance when:
– The vehicle speed is constant or may be assumed to be constant,
– The acceleration and deceleration effects are negligible, and
– There are no delays due to blocking, queues or other congestion effects.
• A measure is also taken of vehicle travel using the ratio (RLE) of
empty versus loaded vehicle travel, ie RLE = TL/ TE, where;
TL total loaded travel time, & TE total empty travel time.

Vehicle Travel Proportions
• A vehicle may be in one of three states at any given time: viz
Travelling Loaded, Travelling Empty or Idle.
• Idle time spent in parking area is used as a performance
measure.
• Then, travel time percentages may be calculated as the
fraction of time that a device is travelling loaded, travelling
empty, and waiting in an idle state; ie, T =TL + TE + TI, where
– T total time, TI total idle time, TL/ TE total loaded/empty travel time
Vehicle Travel: Response Time
• Response time as performance measure, is the time from when
pick-up request is made until vehicle (starting from an idle and
empty condition) arrives at pick-up location) for a pick-up call.
• This measure differs from total empty vehicle transportation
time in that it consists of only empty vehicle travel when the
vehicle starts from an idle position and does not include empty
vehicle travel from a drop-off station to a pick-up station.

Vehicle utilization
• Vehicle utilization may be used to determine the vehicle fleet
size requirements for a system.
• Vehicle utilization may be based on:
– Total vehicle mission time (including loaded and/or empty
vehicle travel),
– The loaded vehicle time and
– The average of the time-averaged loads carried by all
vehicles in the system.
Note: when the vehicles are able to carry multiple loads, the utilization value may be larger than one.
Number of loads completed
• It is defined as the number of loads (or deliveries) completed
over a period of time by all of the material handling vehicles.
• It is considered as a performance measure.
• Some industry measure the time required for the material
handling system to deliver a specified set of loads.

Station Queues: Mean Load Waiting Times
• The mean load waiting time is defined as the mean time
loads wait in queues for material handling transportation.
• These queues are located either at processing stations or at
separate load transfer stations.
Station Queues: Mean Queue Lengths
• The mean queue length is the mean number of loads
waiting for a material handling vehicle over a specific length
of time.
• It is a means of examining the adequacy of the physical
space provided for the queue.
• Blocking occurs when a workstation’s output queue (or
buffer) is full and the Workstation can no longer place
completed parts into this queue.
• Starvation occurs when a workstation’s input queue is
empty.

MHS Cost
• MHS costs may be comprised of variable and fixed costs.
• Variable Costs:
– Generally the operating costs of MHS.
– Can include the cost of power, lubricants, and maintenance.
– May also include the routeing or travel expenses, which are
proportional to the distance travelled.
– may also be includ Costs associated with idle or waiting vehicles
• Fixed Costs: include such costs as the construction and
purchase of equipment and hardware.
• In addition to the use of total cost as a performance measure,
cost ratio (C) is also used as a performance measure which is
defined as: C= C in/ c out, Where
– C in moving cost of one unit load and one unit distance within a
department,
– C out moving cost of one unit load and one unit distance between
departments.

MHS Flexibility
• MHS flexibility is system’s ability to reconfigure (to handle new
material flows) and the material flow capacity.
• Range and Response are defined as dimensions of flexibility.
• Range :how much the system can change.
• Response :how rapidly and cheaply system can change.
Congestion
• Prevents vehicles from travelling freely on a guide path resulting into
travel at reduced speeds/stoppage/blocking.
• Congestion levels may be measured by following quantities;
– Vehicle Blocking Time: Time where vehicles are unable to move due to
other vehicles
– Track Blocking Percentage: Blocking time (as a percentage) for track
segments due to vehicle interference.
– Track Utilization by averaging the utilization of all track segments and
then dividing by the number of AGVs.
– Vehicle Waiting Time at Intersections .
Congestion Index : It(Ic) is defined as: Ic =TA/TS; where,
TA actual travel time, TS shortest travel time if there were no congestion.

THE FUNDAMENTALS OF VARIOUS TYPES
OF
MATERIAL HANDLING EQUIPMENT (MHE)
MHE is mechanical equipment used for the movement,
storage, control and protection of materials, goods and
products throughout the process of manufacturing,
distribution, consumption and disposal.

MATERIAL HANDLING SYSTEMS/EQUIPMENT (MHS/ MHE)
• MHS defined “the set of all pieces of equipment that
make possible the physical movement within the
distribution chain – including the production chain
and WH– of raw material, work in progress and
finished goods”.
• MH refers to the necessary tasks to be performed in
order to move a load around the factory floor as well
as to store and freight it. MH takes place one way or
another along all the links of supply chain including
production, distribution, and storage and retail
functions.
• MHE eases manual handling chores and enhances
operational efficiency.
• MHE can be capital intensive, and act of movement
can be labour intensive.

TYPES OF MHE : TPT EQPT
Transport Equipment
• Used to move material from one location to another (eg
between workplaces, between a loading dock and a storage
area, etc
• Major subcategories : conveyors, cranes, and industrial
trucks. Difference between use of are wrt their path and area
of operation.
• Conveyors: 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.
• Cranes: 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.
• Industrial trucks: Industrial trucks are trucks that are not
licensed to travel on public roads.

TYPES OF MHE: POSITIONING EQPT
Positioning equipment
• Eg; lift/tilt/turn tables, hoists, balancers, manipulators,
and industrial robots.
• Used to handle material at a single location.
• It can be used at a workplace to feed, orient,
load/unload, or otherwise manipulate materials so that
are in the correct position for subsequent handling,
machining, transport, or storage.
• Use of positioning equipment vis-a–vis manual
handling, can raise the productivity of each worker
when the frequency of handling is high, improve product
quality and limit damage to materials and equipment
when the item handled is heavy or awkward to hold and
damage is likely through human error or inattention,
and can reduce fatigue and injuries when the
environment is hazardous or inaccessible

TYPES OF MHE: UNIT LOAD FMN EQPT
Unit load formation equipment
• Used to restrict materials to maintain their integrity when
handled a single load during transport and storage.
• If materials are self-restraining (e.g., a single part or
interlocking parts), then they can be formed into a unit
load with no equipment; eg pallets, skids, tote pans,
bins/baskets, cartons, bags, and crates.
• A Pallet is a platform made of wood, paper, plastic,
rubber, or metal with enough clearance beneath its top
surface to enable the insertion of forks for subsequent
lifting purposes.
• A Slipsheet is a thick piece of paper, corrugated fiber, or
plastic upon which a load is placed and has tabs that can
be grabbed by special push/pull lift truck attachments.
They are used in place of a pallet to reduce weight and
volume, but loading/unloading is slower.

TYPES OF MHE: STORAGE EQPT
Storage Equipment
• Used for holding or buffering materials over a period of
time.
• Design of each type of storage equipment, along with
its use in WH design, represents a trade-off between
minimizing handling costs, by making material easily
accessible, and maximizing the utilization of space (or
cube).
• An AS/RS is an integrated computer-controlled
storage system that combines storage medium,
transport mechanism, and controls with various levels
of automation for fast and accurate random storage of
products and materials.

TYPES OF POWERED TRUCKS USED IN WH
AND STOCK YARD OPERATIONS
• Powered pallet trucks;
• Counterbalanced fork-lift trucks;
• Reach trucks including double reach and four –
directional reach variants;
• Stacker trucks;
• High rack stacker trucks-very narrow aisle;
• Side loaders;
• Order picking trucks;
• Tugs and tractors;
• Straddle carriers-container handling

Non-powered Hand Trucks
• Made of Al/Mg, steel, and wood, they have diverse and
specific applications.
• Designed for specific MH functions.
• Al or Mg trucks carry 150-250 Kgs of material, while steel or
wooden trucks can carry approx 500- 1000 kgs respectively.
Non-powered HPT
• Designed to carry unit loads on pallets from one location to
another in indoor settings.
• Since loads can be heavy, distances are generally short.
• They supplement motorized truck fleets and are extremely
efficient for transporting unit loads short distances when
high lifting is not required.
• Non powered HPT cannot be used to lift >4-5000 and cannot
lift a unit load to a height more than 8 inches.
• For HD applications, steel wheels are required while lighter
duty applications require only nylon or PU construction.
• These trucks can range in weight from 100 to 200 Kgs.

• It is economical way for one
person to move heavy pallet
loads w/o the use of a FLT.
• Pallet truck includes two
articulating steering wheels
and two front load rollers.
• Ergonomic design requires only
40 Kgs of pulling force when
fully loaded.
• Steering wheels include bearing
dust covers for added life.
• Nose wheels are located on the
front edge of each fork to assist
in clean pallet entrance & exit.
• Reinforced triple formed steel
forks provide twice the strength
of standard single-formed
forks.
PALLET TRUCKS

• HPT with capacities
2 T (max), are most
commonly used for
the horizontal
movement of pallets.
It could be vehicle
towed.
• For frequent
movements and
inclined movement
battery –powered
trucks are
preferable in terms
of operator effort
and safety, and
these can be
pedestrian – or
rider- controlled.
POWERED PALLET TRUCKS

COUNTER BALANCED FORK-LIFT TRUCKS
• Counterbalanced FLT
carry the payload
forward of the front
wheels, so there is
always a turning
moment lending to tip
forward.
• To balance this, a
counter balance weight
is built into the rear of
the machine-hence the
name. These machines
capacity varies from
1000 to 45,000 kgs
with a lift height of up
to 6/7 M.

REACH TRUCKS
• Reach trucks are designed to be
smaller and lighter than counter-
balanced trucks and to operate
in a smaller area.
• Its capacity varies from 1000kgs
to 3,500 kgs with a max fork-lift
up to about 11 M, achieved by
having a mast that can move
forward or back in channels in
the outrigger truck legs.
• Then picking up or setting down
a load, the truck is turned
through 90 deg to face the load
location; the mast reaches
forward, places or retrieves the
load, and is retracted back into
the area enclosed by the wheels.

DOUBLE REACH TRUCKS
• A conventional reach truck
can only reach one pallet
deep into racking.
• For accessing double deep
racking a double reach truck
has to be used, which uses a
pantograpgh mechanism to
achieve the additional reach.
• Double reach can also be
achieved on some lighter
trucks by the use of
telescopic forks.
• Double reach machines are
also used for side-loading
pallets on to road vehicles,
working only from one side of
vehicle.

FOUR-DIRECTIONAL REACH TRUCKS
• On a conventional reach truck,
front wheels always face forward,
and steering is from the rear
wheels.
• 4D truck has an additional option
of being able to turn front wheels
through 90 deg and lock them in
this mode.
• This effectively converts truck into
a side loader and is especially
useful in stores and WHs where
stock range consists of long loads.
• For access to say cantilever
storage, very wide aisles would be
necessary if this option were not
available.

MULTI-ECHELON INVENTORY SYSTEMS

ECHELON INVENTORY SYSTEMS
• Echelon Inventory: All inventories between a stage
and final customer.
• Echelon inventory at a retailer is just the inventory at
retailer or in the pipeline coming to retailer.
• Echelon inventory at a distributor, however, includes
inventory at distributor and all retailers served by
him/her.
• In a Multi-echelon setting, reorder points and order
up to levels at any stage should be based on echelon
inventory and not local inventory.
• Thus, a distributor should decide his safety inventory
levels based on the level of safety inventory carried by all
retailers supplied by him.
• The more safety inventory retailers carry the less safety
inventory the distributor will need to carry.

ECHELON INVENTORY SYSTEMS (contd)
• As retailers decrease the level of safety inventory they
carry, the distributor will have to increase his or her
inventory to insure regular replenishment at the retailers.
• The level of safety inventory at all stages in a multi-
echelon supply chain should be related.
• In a multi-echelon supply chain a decision must be made
with regard to the level of safety inventory carried at
different stages.
• If inventory is very expensive to hold and customers
are willing to tolerate a delay, it is better to increase the
amount of safety inventory carried upstream, far from the
final customer, to exploit the benefits of aggregation.
• If inventory is inexpensive to hold and customers are
very time sensitive, it is better to carry more safety
inventory downstream, closer to the final customer.

MAJOR PITFALLS OF MANAGING INVENTORY
IN A MULTI-ECHELON NETWORK
• Failure to achieve true network inventory optimization,
because replenishment strategies are applied to one
echelon without regard to its impact on other echelons.
• Base upper-echelon replenishment decisions on
specious demand forecasts.
• Negative consequences of pitfalls;
– Network carries excess inventory in form of redundant SS.
– End customer service failures occur even when adequate
inventory exists in the network.
– Customer-facing locations experience undesirable stock outs,
while service between echelons is more than acceptable.
– External suppliers deliver unreliable performance, because
they have received unsatisfactory demand projections.
– Short-sighted internal allocation decisions are made for
products with limited availability.

AUTOMATED STORAGE & RETRIEVAL
SYSTEMS (AS/RS)

AS/RS : GENERAL
• It consists of a variety of computer-controlled
systems for automatically placing and retrieving
loads from defined storage locations.
• They are typically used in applications where;
– There is a very high volume of loads being moved
into and out of storage;
– Storage density is important because of space
constraints;
– No value adding content is present in this
process;
– Accuracy is critical because of potential expensive
damages to the load.
• AS/RS can be used with standard loads as well as
nonstandard loads.

WHAT IS AS/RS ?
• AS/RS are means to high density hands free
buffering of materials in distribution and
manufacturing environments.
• AS/RS is a complete system designed to transport,
stage/store, retrieve, and report on every item in
any industrial inventory with up-to-the minute
accuracy.
• These automated storage and mechanized systems
eliminate human intervention in performing
basic sets of operations that includes :
– Removal of an item from a storage location
automatically
– Transferring the above item to a specific processing
or interface point
– After receiving an item from a processing or interface
point, it is automatically stored at a predetermined
location.

OBJECTIVES FOR INSTALLING AN AUTOMATED
STORAGE SYSTEM IN A FACTORY
• Increasing the storage capacity
• Increasing the stock rotation
• Utilization of maximum floor space
• Recovering the space for manufacturing facilities
• Customer service to be improved
• Control over inventories to be improved
• Ensuring safety in storage function
• Increasing the labour productivity in storage
function
• Reducing labour cost in storage operation
• Reducing pilferage and improving security

DEFINITION AS/RS
• AS/RS can be defined as a storage system under
which a defined degree of automation is to be
implemented to ensure precision, accuracy and
speed in performing storage and retrieval
operations.
• These automated storage and mechanized
systems eliminate human intervention in
performing basic sets of operations to include;
– Removal of an item from a storage location
automatically
– Transferring the above item to a specific processing
or interface point
– After receiving an item from a processing or
interface point, it is automatically stored at a
predetermined location.

PRINCIPLE TYPES OF AS/RS
• Unit Load AS/RS: It is the generic AS/RS
– It is used to store and retrieve loads that are
palletized or stored in standard-sized
containers.
– The system is computer controlled.
– The S/R machines are automated and designed
to handle the unit load containers.
– Usually, a mechanical clamp mechanism on the
S/R machine handles the load.
– However, there are other mechanisms such as
a vacuum or a magnet-based mechanism for
handling sheet metal.
– The loads are generally over 200 Kgs per unit.

PRINCIPLE TYPES OF AS/RS (contd)
• Mini Load AS/RS :
– This system is designed to handle small
loads such as individual parts, tools, and
supplies that are contained in bins or
drawers in the storage system.
– This system is applicable where the
availability of space is limited.
– Also useful where the volume is too low for a
full-scale unit load system and too high for
a manual system.
– A mini load AS/RS is generally smaller than
a unit load AS/RS and is often enclosed for
security of items stored.

• Deep-lane AS/RS :
– This is a high-density unit load storage system that
is appropriate for storing large quantities of stock.
– The items are stored in multi deep storage with up
to 10 items in a single rack, one load behind the
next.
– Each rack is designed for flow-through, with input
and output on the opposite side.
– Machine is used on the entry side of the rack for
input load and loads are retrieved from other side
by an S/R- type machine.
– The S/R machines are similar to unit load S/R
machine except that it has specialized functions
such as controlling rack-entry vehicles.

• Man-on-board AS/RS :
– This system allows storage of items in less than
unit load quantities.
– Human operator rides on the carriage of the S/R
machine to pick up individual items from a bin or
drawer.
– The system permits individual items to be picked
directly at their storage locations.
– This provides an opportunity to increase system
throughput.
– The operator can select the items and place them in
a module.
– It is then carried by the S/R machine to the end of
the aisle or to a conveyor to reach its destination.

• Automated Item Retrieval System :
– This system is designed for retrieval of individual
items or small product cartoons.
– The items are stored in lanes rather than bins or
drawers.
– When an item is retrieved from the front by use of a
rear-mounted pusher bar, it is delivered to the
pickup station by pushing it from its lane and
dropping onto a conveyor.
– The supply of items in each lane is periodically
replenished and thus permitting first-in/first-out
inventory rotation.
– After moving itself to the correct lane, the picking
head activates

ADVANTAGES
An effective AS/RS provides benefits for SCM;
• Helps companies cut expenses by minimizing the
amount of unnecessary parts and products in
storage, and improving organization of the
contents of a WH.
• Due to automated processes, it also allows for
more storage space due to high-density storage,
narrower aisles, etc.
• Reduces labor costs while lowering workforce
requirements and increasing safety.
• Modelling and managing the logical
representation of the physical storage facilities
(e.g. racking, etc) eg, if certain products are often
sold together or are more popular than others,
those products can be grouped together or placed
near the delivery area to speed up the process of
picking, packing and shipping to customers.

ADVANTAGES (contd)
Enabling a seamless link to order processing
and logistics management in order to pick, pack,
and ship product out of the facility.
• Tracking where products are stocked, which
suppliers they come from, and the length of time
they are stored.
• By analyzing such data, companies can control
inventory levels and maximize the use of WH
space.
• Firms are better prepared for the demands and
supplies of the market, especially during special
circumstances such as a peak season on a
particular month.
• Through the reports generated by an AS/RS
system, firms are also able to gather important
data that may be put in a model for it to be
analyzed.

BAR CODING TECHNOLOGY &
APPLICATIONS IN LOGISTICS INDUSTRY

BAR CODE (B/C)
• A B/C does not change how a business operates,
but makes procedures faster and more accurate,
providing useful Mgt Info in a timely manner.
• B/C can be employed in virtually all orgs and all
professions to increase productivity, efficiency
and accuracy of specific business processes.
• A B/C is a set of symbols used to represent
alpha-numeric information. Basically, instead of
seeing the number "1” or letter "A", one sees a series
of bars, both fat and thin, used to represent that
number.
• It's much quicker and much more accurate for a
mechanical device to decode a series of black
and white lines than it is to read human text.

VARITIES OF B/C
• Linear: A linear B/C symbology consists of a single row
of dark lines and white spaces of varying but specified
width and height
• 2-Dimensional: 2-Dimensional symbology can be
configured into a stacked or matrix format. These are
special rectangular codes which ‘stack’ information in a
manner allowing for more information storage in a
smaller amount of space.
• The amount of data that can be encoded: A one inch
2-D matrix, can encode thousands of characters of data,
whereas a comparable linear bar code would have to be
several feet long to hold the same amount of information.

COMPONENTS OF BAR CODING
• B/C systems come in different sizes and shapes.
• The complexity of system required is determined by the
application.
• A basic scanning system comprises of four components:

COMPONENTS OF BAR CODING (contd)
• Component1:The B/C Printer to print B/C Labels.
• Component2-The B/C Label to be attached to a box or
an asset for tracking. An item label can contain any
combination of text, graphic or bar code information.
• Component3-Scanning Equipment for Data Collection
to instantly and accurately read, capture and decipher
the information contained in the B/C label. Scanners are
much faster and more reliably than humans. Thus,
significantly reducing rate or likelihood of error. Types:
– Contact scanners required physical contact to scan.
– non-contact scanners which can be several inches to feet away.
– Of these two types of scanners, there is also one other major
attribute; they are either decoded or non-decoded. Decoded
scanners have built in H/W decoders that interpret the meaning
of a B/C before sending the data to the computer. Undecoded
scanners simply have light sources that capture the encrypted
data and sends them to a decoder of some sort.

COMPONENTS OF BAR CODING (contd)
• Component4 – Capturing the Data to an External
Database: The final component to establishing a simple
B/C system is the database.
• To effectively use the codes created and scanned, A
database is required to relay and update information.
• Many B/C can be tied to item numbers , which can then,
in turn, be linked to information about the item, such as
product description, price, inventory quantity, acctg etc.
• Eg, let's say there is widget A, with a corresponding bar
code that has the value of 1234. When widget A is sold,
the B/C is scanned.
• This, in turn, causes a chain reaction that tells database
that now one less widget A in stock, that charge Rs
200 for widget A, that this information be passed onto
accounting etc. All of these actions were caused by
scanning the B/C representing Widget A.

ADVTS OF B/C & AUTOMATIC DATA
COLLECTION
• Accuracy: By reducing the likelihood of human
errors from manual entry or miscommunication
from misread or mislabeled items.
• Ease-of-Use : B/C are easy-to-use provided
appropriate H/W & S/W aspects are in place to
maximize process of automatic data collection as
compared to accounting for all the inventory by
hand.
• Uniform Data Collection: Diverse compliance
standards and standardized B/C symbologies
ensure that B/C information is captured and
relayed in a fashion that is universally understood
and accepted.

ADVTS OF B/C & AUTOMATIC DATA
COLLECTION (contd)
• Timely Feedback: B/C promotes timely
feedback in that data is captured in real-time as
it occurs enabling decisions to be made from
current information.
• Improved Productivity: B/C improve many
activities that streamline workflows throughout
a business.
• Increased Profitability: Through increased
efficiencies .

PRIMARY FUNCTIONS OF B/C TECHNOLOGY
Tracking
• Anything that can be identified with numbers &/or
letters can be tracked using B/C technology.
• Apart from greater accuracy, B/C help speed process of
recording where and what an item is, or what service is
provided.
• To track product through out supply chain/ workflow.
• B/C numbers also can be used to track a particular item
back to the manufacturer, eg , if a user discovers a
defective supply item, B/C can help track the item back
through materials management and purchasing to the
distributor and/or OEM so the he/organisation can
obtain a refund, the same thing done manually, the
amount of time involved would make the process too
cumbersome.

PRIMARY FUNCTIONS OF B/C TECHNOLOGY (contd)
Inventory Management
• Maintaining accurate inventory: a very complex process,
requires knowing;
– what is,
– how much of it,
– who has it,
– where it is,
– how much it is worth, and
– when to reorder it.
• B/C helps manage these inventories wherever they are
located, so that the right materials are available when
and where you need them.
• Using a B/C also can help monitor usage patterns
throughout supply chain.

PRIMARY FUNCTIONS OF B/C TECHNOLOGY (contd)
Validation
• The validating function of B/C is an effective
method of ensuring quality.
• Validation assures that an action has taken
place or that the item required is on hand.
• The ability to validate an action by a B/C scan
helps reduce errors and waste, provides check
on productivity, and helps construct the
necessary documentation.

RADIO FREQUENCY IDENTIFICATION
(RFID)
TECHNOLOGY & APPLICATIONS IN
LOGISTICS INDUSTRY
RFID is the wireless use of EM Fields to
transfer data, for the purposes of
automatically identifying and tracking tags
attached to objects

THE ARCHITECTURE OF RFID
1.A passive RFID tag,
• which, when exposed to the EMW of the reader,
broadcasts its Electronic Product Code (EPC) info.
• Tags are attached to all objects to be identified in an
RFID system.
• A tag is typically composed of an antenna or coupling
element, and integrated circuitry.
• Often tags carry no on-board power source and must
passively harvest all energy from an RF signal.
• There are many types of tags that offer different
functionalities, have different power sources, or operate
at different radio frequencies. Each of these variables
helps determine which applications a particular tag
may be appropriate for and what the costs of a tag may
be.

THE ARCHITECTURE OF RFID (contd)
2. An RFID Reader;
• RFID readers communicate with tags through an RF
channel to obtain identifying information.
• In environments with many tags, a reader may have to
perform an anti-collision protocol to ensure that
communication conflicts to not occur.
• Anti-collision protocols permit readers to rapidly
communicate with many tags in serial order.
• Readers often power what are called passive tags
through their RF communication channel.
• These types of tags carry no on-board power and rely
solely on a reader to operate. Since
• these tags are so limited, may subsequently rely on a
reader to perform computation as well.

3.Databases
• RFID databases associate tag-identifying data
with arbitrary records.
• These records may contain product information,
tracking logs, sales data, or expiration dates.
• Independent databases may be built throughout
a supply chain by unrelated users, or may be
integrated in a centralized or federated database
system.
• Databases are assumed to have a secure
connection to readers.
.

4.Power Sources
• Tags may obtain their power in several different ways.
• Power source is an essential property of a tag-potential read
range, lifetime, cost, and what kind of functionalities it may
offer depends on it.
• Power source will also be important in determining how a tag
may be oriented and what physical forms it may take.
• There are three main classes of tag power sources: active,
semi-passive, and passive.
• Active tags;
– Have their own source of power, such as a battery, and may
initiate communication to a reader or other active tags.
– Active tags typically have a much longer operating range than
passive-tags.
– Large asset and livestock tracking applications often use active
tags, since the items they are attached to (e.G. Railcars, shipping
or cattle) are high in value and have physical space for a bulkier,
rugged tag.

• RFID tag responds to reader broadcasting its
EPC, a 96bit code:
– 8 bits of header information.
– 28bits identifying the organization that
assigned the code
– 24 bits identifying the type of product.
– 36 bits representing serialization information
for the product

RFID VS BARCODE
• Cost of a tag is higher than cost of a printed
B/C label.
• B/C can be read only the LoS; labels must be
positioned to be directly visible to B/C reader.
RFID tags need to be within RFID reader’s
radio reach (about 10 ft).
• B/C cannot be read inside other containers,
RFID tags can be read through most materials.
Thus, contents can be verified easily without the
costly overhead of an “Open Box Inspection” and
manual counts.

RFID VS BARCODE (contd)
• B/C provide only limited amounts of
information –even two-dimensional B/C are
limited in the amount of data they can carry. The
Auto ID center’s definition of a product
information server allows us to tie unlimited
amounts of dynamic information to each tag.
• B/C identify classes of products –RFID tags
identify individual products.
• Migration of supply chains from B/C to RFID
will require significant investments and will
not happen overnight, RFID and B/C will co
exist.

BENEFITS OF RFID
• RFID tag can be affixed to an object and used to track and
manage inventory, assets, people, etc, eg, it can be affixed
to cars, computer equipment, books, mobile etc.
• Increased Labour Productivity: Spec in receiving area of
WH as RFID eliminates manual operations allowing
product’s faster move to storage/outbound dock.
• Inventory Reduction:
• With RFID in WH, it provide more visibility to the
products so their location is more easily determined
and it reduces likelihood of a stock-out occurring
because of misplaced inventory or inaccurate inventory
levels.
• Cycle service levels will also improve due to lower safety
stock levels and the overall faster throughput of
product at a WH.
• RFID shall reduce total system inventory by approx 5%.

BENEFITS OF RFID (contd)
• Facility/Equipment productivity :
– RFID allows more data to be processed faster through
a WMS which uses the acquired information to
improve the operations of WH.
– eg, vehicles scanning at inbound gates of WH,
improves dock utilization because the WMS can more
effectively assign vehicles to unloading doors based on
order priority.

OTHER BENEFITS OF RFID
• Shrinkage: Product stolen by employees along with
misplaced items, shall reduce as WH will have a better
understanding of product’s location and difficulty to move
products out of WH.
• Forecast accuracy will also increase due to higher levels
of visibility of product throughout supply chain, positively
affecting overall efficiency and effectiveness of WH in areas
such as:
– Order cycle times;
– Safety stock levels;
– Fulfillment accuracy; and,
– Cycle service levels.
• Despite individual tag being expensive as compared to
B/C and inappropriate for the tagging of low-cost items but;
tags are reusable and have very long lives, saving on
manpower and other costs associated with label production
and fixing.

RFID IN RETAILING SECTOR
• RFID is an automatic identification and data
capture (AIDC) technology ie non-contact reading
to track and monitor physical objects.
• A key benefit of RFID is automatic identification of
individual objects coupled with automatic data
capture.
• Automatic electronic identity contributes
significantly to enhance supply chain visibility,
and automation brings in data capture and has a
direct bearing on operational efficiency in labor
intensive Retail Logistics.

RFID IN RETAILING SECTOR (contd)
Supply Chain Visibility
• Visibility into merchandise pipeline within enterprise is
extremely critical to ensure that an optimal level of
inventory is maintained – not too much to lock in excess
working capital, and not too less to cause stock-outs.
• Lack of visibility results in insufficient coord between
material flow and information flow often causing a
magnification of demand variability in each level up in the
supply chain –the bullwhip effect.
(BE is a distribution channel phenomenon in which forecasts yield
supply chain inefficiencies. It refers to increasing swings in inventory
in response to shifts in customer demand as you move further up
the supply chain. BE was named for the way the amplitude of a whip
increases down its length. The further from the originating signal,
the greater the distortion of the wave pattern. In a similar manner,
forecast accuracy decreases as move upstream along the supply
chain, eg, many consumer goods have fairly consistent consumption
at retail. But this signal becomes more chaotic and unpredictable as
you move away from consumer purchasing behavior.

Operational Efficiency
• Logistics Management- a key element of cost in a retail
enterprise encompasse all activities that enable the
movement of merchandise from vendor/mfr to PoS.
• About 25-30% of supply chain costs can be attributed to
labor costs in the process of distributing merchandise.
• Retailers extensively use SW tools for WH, Yard &
transportation management.
• Industrial automation systems like conveyors, carousels,
unit sorters enable enhanced operational efficiency
within the distribution center.
• Business process innovations like multi-order picking,
pick-to-light, use of voice and wireless technologies have
all contributed significantly to higher productivity in
warehouse operations.

Potential Benefits of RFID to Retail Enterprises
• With falling prices of tags and readers, RFID a viable
option for pallet and case level tagging.
• Retailers stand to gain when individual items are tagged,
with significant opportunities in enterprise inventory
management and retail store operations.
• While the current tag costs rule out the economic
viability of item/unit level tagging in most cases, there
still could be a good business case in certain specific
merchandise categories and applications.
• Pallet and Case level tagging also has the potential to
enhance operational efficiency for the Retailer.
• The likely return on investment from RFID tagging varies
largely, and is an inverse function of the current level of
process optimization.

RFID IN WAREHOUSINGReceiving
• Whereas current B/C require scanning each product or
case before it’s moved into WH, RFID allows
improvements in Throughput Speed of product at the
receiving dock.
• RFID scanner reads the shipment within seconds as it
passes through the portal readers.
• RFID eliminates need to physically check the bill of lading
and/ or the packing slip.
• RFID will connect with the WMS to indicate if a product
needs a cross-dock movement.
• RFID system will help manage flow of damaged goods into
the WH. The damaged goods set aside can be read by
RFID as received as damaged; significantly reduce labor
hours spent on managing the damaged goods process.
• An RFID system also offers greater efficiencies in WH
systems that rely on conveyors.

RFID IN WAREHOUSING (contd)
Storage
• RFID provides benefits in put-away accuracy and
efficiency.
• FLT drivers could still rely on current WMS system to
identify the locations for pallets and products. However,
an RFID system can eliminate the need to scan B/C on
the pallet and at the slot location in the racks, eg, if the
pallet and slot location read by the RFID scanner do not
match the WMS specification, the system notifies the
driver that the product has been placed in the wrong
location.
• Moreover, the need for additional B/C on each pallet is
eliminated.
• RFID has potential to improve temporary storage at WH.
• Since the RFID tags can be read from anywhere, products
and pallets do not have to be placed in specific or
assigned locations.

RFID IN WAREHOUSING (contd)
Pick / Pack
• RFID readers can integrate with the WMS and OMS
systems to ensure that the correct items and amounts are
picked.
• RFID helps to measure productivity in WH. Through a
type of RFID-enabled time-motion measurement,
management could analyze the process to set benchmarks,
evaluate employees and plan labor requirements.
Shipping
• RFID reader can confirm that each item is placed onto the
correct outbound vehicle, which can improve the accuracy
of the shipping process.
• This verification can be made as the product moves
through the portal of the outbound dock door.
• These processes allow for an automatic double check of
the items loaded into the trailer against the bill of lading

Warehouse Management System

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