UPSC MainsMANAGEMENT-PAPER-II20215 Marks
Q4.

Economic Order Quantity (EOQ) Calculation

An engineering firm has determined that for a particular part, the cost of purchase is ₹ 350 per order and ₹ 22 per part. Its inventory carrying cost is 15% of the average inventory. The firm currently purchases ₹ 2,20,000 worth of this part every year. (i) Determine the Economic Order Quantity (EOQ). (ii) What is the optimum number of days supply per optimum order?

How to Approach

This question tests the application of Operations Management principles, specifically inventory management. The candidate should demonstrate understanding of the Economic Order Quantity (EOQ) model and its components. The answer should clearly show the calculations for EOQ and then use that result to determine the optimum number of days of supply. A structured approach, defining EOQ, presenting the formula, showing the calculations, and then interpreting the results is crucial.

Model Answer

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Introduction

Inventory management is a critical aspect of operations, directly impacting a firm’s profitability and efficiency. Maintaining optimal inventory levels is a balancing act between minimizing costs associated with holding inventory and avoiding stockouts. The Economic Order Quantity (EOQ) model is a widely used technique to determine the ideal order quantity that minimizes the total inventory costs – ordering costs and carrying costs. This question requires us to apply the EOQ model to an engineering firm’s part procurement process, calculating the optimal order quantity and the corresponding days of supply.

Understanding the EOQ Model

The Economic Order Quantity (EOQ) is the order quantity that minimizes the total inventory costs. It’s based on the following assumptions: demand is constant and known, lead time is constant, ordering costs are constant, carrying costs are constant, and there are no stockout costs.

Formula for EOQ

The EOQ is calculated using the following formula:

EOQ = √(2DS / H)

Where:

  • D = Annual demand in units (or value)
  • S = Ordering cost per order
  • H = Annual carrying cost per unit

Calculating the EOQ

In this case:

  • D = ₹ 2,20,000 (Annual demand value)
  • S = ₹ 350 (Ordering cost per order)
  • Carrying cost = 15% of average inventory value

First, we need to determine the average inventory value. The average inventory is EOQ/2. Therefore, the carrying cost (H) is 0.15 * (EOQ/2). Substituting this into the EOQ formula makes it complex to solve directly. Instead, we can work with the cost per part.

Annual demand in units = Total annual value / Cost per part = ₹ 2,20,000 / ₹ 22 = 10,000 units

Now, we can recalculate the parameters:

  • D = 10,000 units (Annual demand in units)
  • S = ₹ 350 (Ordering cost per order)
  • H = 15% of ₹ 22 = ₹ 3.30 (Annual carrying cost per unit)

EOQ = √(2 * 10,000 * 350 / 3.30) = √(2121212.12) ≈ 1456.4 units

Therefore, the Economic Order Quantity (EOQ) is approximately 1456 units.

Determining the Optimum Number of Days Supply

To determine the optimum number of days supply per optimum order, we need to calculate the number of days the EOQ will last based on the annual demand.

Days supply = (EOQ / Annual demand in units) * 365

Days supply = (1456 / 10,000) * 365 ≈ 52.5 days

Therefore, the optimum number of days supply per optimum order is approximately 53 days.

Sensitivity Analysis

It's important to note that the EOQ model is sensitive to changes in demand, ordering costs, and carrying costs. Any significant fluctuations in these parameters would necessitate a recalculation of the EOQ.

Conclusion

In conclusion, the engineering firm should order approximately 1456 units of the part per order to minimize its total inventory costs. This order quantity will provide approximately 53 days of supply. Implementing the EOQ model will help the firm optimize its inventory management, reduce costs, and improve overall operational efficiency. Regularly reviewing and adjusting the EOQ based on changing market conditions and cost structures is crucial for sustained benefits.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Economic Order Quantity (EOQ)
The EOQ is an inventory management technique used to determine the optimal order quantity to minimize total inventory costs, including ordering costs and holding costs.
Carrying Cost
Carrying cost, also known as holding cost, represents the total cost of storing and maintaining inventory, including costs like warehousing, insurance, obsolescence, and capital tied up in inventory.

Key Statistics

Inventory costs typically represent 20-30% of total operating costs for many businesses (Source: APICS, 2023 - knowledge cutoff).

Source: APICS (Association for Supply Chain Management)

Globally, approximately $1.7 trillion worth of inventory is written off annually due to obsolescence and damage (Source: McKinsey, 2022 - knowledge cutoff).

Source: McKinsey & Company

Examples

Toyota's Kanban System

Toyota's Kanban system, a pull-based inventory management system, is a real-world example of optimizing inventory levels. It minimizes waste and ensures that parts are only produced when needed, reducing carrying costs and improving efficiency.

Frequently Asked Questions

What happens if the demand is not constant?

If demand is not constant, the basic EOQ model may not be accurate. More advanced inventory management techniques, such as safety stock calculations and dynamic EOQ models, should be used to account for demand variability.

Topics Covered

BusinessEconomicsOperations ManagementInventory ManagementEOQCost Analysis