3. Inventory Definition
A stock of items held to meet future
demand
Inventory is a list for goods and
materials, or those goods and
materials themselves, held available in
stock by a business.
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4. Introduction
Constitute significant part of current assets
On an average approximately 60% of current assets in Public Limited Companies in
India
A considerable amount of fund is required
Effective and efficient management is imperative to avoid unnecessary investment
Improper inventory management affects long term profitability and may fail
ultimately
10 to 20% of inventory can be reduced without any adverse effect on production
and sales by using simple inventory planning and control techniques
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5. Work in
process
Vendors Raw Work in Finished Customer
Materials process goods
Work in
process
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6. Nature of Inventories
Raw Materials – Basic inputs that are converted into finished product through
the manufacturing process
Work-in-progress – Semi-manufactured products need some more works before
they become finished goods for sale
Finished Goods – Completely manufactured products ready for sale
Supplies – Office and plant cleaning materials not directly enter production but
are necessary for production process and do not involve significant investment.
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7. Objective of Inventory Management
To maintain a optimum size of inventory for efficient and smooth production
and sales operations
To maintain a minimum investment in inventories to maximize the profitability
Effort should be made to place an order at the right time with right source to
acquire the right quantity at the right price and right quality
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8. An effective inventory management should
Ensure a continuous supply of raw materials to facilitate uninterrupted
production
Maintain sufficient stocks of raw materials in periods of short supply and
anticipate price changes
Maintain sufficient finished goods inventory for smooth sales operation,
and efficient customer service
Minimize the carrying cost and time
Control investment in inventories and keep it at an optimum level
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9. An optimum inventory level involves
three types of costs
Ordering costs:- Carrying costs:-
Quotation or tendering
Warehousing or storage
Requisitioning
Order placing Handling
Transportation Clerical and staff
Receiving, inspecting and storing
Insurance
Quality control
Clerical and staff Interest
Stock-out cost Deterioration,shrinkage,
Loss of sale
evaporation and
Failure to meet delivery
commitments obsolescence
Taxes
Cost of capital
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10. Dangers of Over investment
Unnecessary tie-up of firm’s fund and loss of profit – involves opportunity
cost
Excessive carrying cost
Risk of liquidity- difficult to convert into cash
Physical deterioration of inventories while in storage due to mishandling and
improper storage facilities
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11. Dangers of under-investment
Production hold-ups – loss of labor hours
Failure to meet delivery commitments
Customersmay shift to competitors which
will amount to a permanent loss to the firm
May affect the goodwill and image of the
firm
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12. Classification of inventory
• ABC Classification
• HML Classification
• XYZ Classification
• VED Classification
• FSN Classification
• SDF Classification
• GOLF Classification
• SOS Classification
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13. ABC Classification
• In most of the cases 10 to 20 % of the inventory
account for 70 to 80% of the annual activity.
• A typical manufacturing operation shows that the top
15% of the line items, in terms of annual rupees usage,
A
represent 80% of total annual rupees usage.
• Next 15% of items reflect 15% of annual rupees
• Next 70% accounts only for 5% usage
B
C 13
14. XYZ Classification
On the basis of value of inventory
stored
Whereas ABC was on the basis of
value of consumption to value.
X – High Value
Y – Medium value
Z – Least value
Aimed to identify items which are
extensively stocked.
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15. HML Classification
On the basis of unit value of item
There is 1000 unit of Q @ Rs. 10 and 10,000 units of W @ Rs. 5.
Aimed to control the purchase of raw materials.
H – High, M- Medium, L - Low
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16. VED Classification
• Mainly for spare parts because their consumption
pattern is different from raw materials.
Therefore V items has to be stocked more
• Raw materials on market demand
• Spare parts on performance of plant and machinery.
• and D Items has to be less stocked
V – Vital, E – Essential, D – Desirable
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17. FSN Classification
According to the consumption pattern
To combat obsolete items
F – Fast moving
S – Slow moving
N – Non Moving
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18. SDF & GOLF Classification
Based on source of procurement
S – Scarce, D- Difficult, E- Easy.
GOLF
G – Government, O – Ordinary, L – Local, F – Foreign.
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19. SOS Classification
Raw materials especially for agriculture units
S – Seasonal
OS – Off seasonal
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20. EOQ – Three Approaches
Trial and Error method
Order-formula approach
Graphical approach
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21. EOQ & Re-order point
EOQ – gives answer to question
“How much to Order”
Re-order point – gives answer
to question “when to order”
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23. Order- Formula approach
1/2
EOQ =(2CO/I)
C = Annual demand
O = Ordering cost per order
I = Carrying cost per unit
1/2
EOQ =(2*1200*37.5/1) = 300 units
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25. A Review
So we have dealt with
1. EOQ model
2. Its extension
3. And now we will be dealing with special inventory
models
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26. Special inventory model
Non – Instantaneous replenishment
Quantity Discount
One – period decision
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27. Special inventory model
Non – Instantaneous replenishment
Capacity 10 units
A B C D
Thus the inventory is replenished gradually than in lots
Particularly in situation were manufacturers use continues
production process
e.g. FACT makes Ammonium on a continual basis27
28. Special inventory model
Discount Quantities
If discount increases with the order quantity, then the price of
inventory is no more constant
Hence a new approach is needed to find the
best lot size
Total Annual holding Annual Annual cost of
cost = cost + ordering cost + materials
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29. Special inventory model
One period decisions
The newsboy problem
If a newspaper seller does not buy enough papers to resell on the
street corner, sales opportunity is lost. If the seller buys too many, the
overage cannot be sold because nobody wants yesterdays newspaper.
Applicable to fashion goods, seasonal goods and
due to change in technology 29
30. Inventory management
under uncertainty
1. Option price model
2. Risk adjusted discount cash flow (DFC) Model
3. Dynamic inventory model
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31. Option price model
Option is a contract that gives the holder a right to
acquire or sell certain things at a predetermined price
without any obligation.
Calculated by integrating the market information and
inventory control.
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32. Risk adjusted discount cash
flow (DFC) Model
• Inventory control problem is converted to capital
budget problem
Beneficial afor projects like to hold an
• Suppose television dealer decides oil drilling were the
additional inventory of 1000 television per month. The
benefit of holding inventory is spread overtime.
cost is acquired only after a long time but
once Inflows = struck the additional expanse is covered.
• oil is no: of units × probability × present value
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33. Dynamic inventory model
1. Uncertain variables are identified
2. Probability associated with them is taken
3. Simulation techniques are applied
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34. Emerging trends in inventory
management
• Entering into log term contract at a fixed price to
reduce uncertainties
• Just-in-time
• Kanbans – Japanese technique (Only produce when
demand comes)
• Internet based ordering system
• Vendor development
• Investment in plant and machinery
• Continuous-flow manufacturing
• Visual control
• Supply chain management
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35. Theories under Supply chain Managment
Resource-based view (RBV)
Transaction Cost Analysis (TCA)
Knowledge-Based View (KBV)
Strategic Choice Theory (SCT)
Agency Theory (AT)
Institutional theory (InT)
Systems Theory (ST)
Network Perspective (NP)
Materials Logistics Management (MLM)
Just-in-Time (JIT)
Material Requirements Planning (MRP)
Theory of Constraints (TOC)
Performance Information Procurement Systems (PIPS)
36. Performance Information Risk Management System (PIRMS)
Total Quality Management (TQM)
Agile Manufacturing
Time Based Competition (TBC)
Quick Response Manufacturing (QRM)
Customer Relationship Management (CRM)
Requirements Chain Management (RCM)
Available-to-promise (ATP)
and many more
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