What Is Inventory Control? Methods, Formulas & Best Practices

Inventory Control vs. Inventory Management

Inventory control and inventory management are related but not exactly the same. Inventory control is part of inventory management . You cannot manage inventory properly if your stock records are inaccurate. Check the table below for a comparative analysis:

Why Is Inventory Control Important?

Inventory control matters because it has a big impact on your sales, cash flow, record-keeping, and customer satisfaction. It lets you reorder in time so you never run out of stock, but also stops you from buying too much and tying up your money in unsold goods.

A strong inventory control process makes it easier to identify dead stock before it becomes a write-off and reduces losses from wastage, expiry, damage, or shrinkage. It also helps maintain accurate stock valuation for accounting, supports better purchase planning through real sales data, and keeps stock records organized for GST and business reporting.

Common Inventory Control Challenges

1. No real-time stock visibility
Many businesses still use manual registers or spreadsheets, making it tough to know exactly how much stock is on hand, especially with sales, purchases, returns, and transfers happening every day.

2. Manual entry errors
Entering an incorrect quantity, missing a purchase, using a duplicate item name, or selecting the wrong unit can easily mess up your stock records. These mistakes can cause headaches later with billing, purchase planning, GST records, and determining your actual stock value.

3. Overstocking: When a business buys more than it can sell quickly, money gets stuck in unsold stock, and storage costs go up. In industries such as food, pharma, cosmetics, and FMCG, this can also mean incurring losses from expired items.

4. Stockouts: This is when customers want something, but you don’t have it in stock. That means lost sales, unhappy customers, delayed deliveries, and sometimes having to make urgent purchases at a higher price.

5. Shrinkage

Shrinkage is when the stock you think you have on paper is more than what’s actually there. It can happen because of theft, damage, expiry, billing errors, short deliveries from suppliers, wastage, or simple data entry mistakes . 

(Formula: Shrinkage (%) = [(Recorded stock value - Physical stock value) ÷ Recorded stock value] × 100)

6. Dead stock

Dead stock refers to items that haven’t sold or moved for a long time and are unlikely to sell anytime soon. They just sit there blocking shelf space, warehouse space, and money. Regular FSN analysis can help spot dead stock early, so you can take action.

Types of Inventory Control Systems

Periodic Inventory System

In a periodic inventory system, stock is counted and updated at fixed intervals, such as weekly, monthly, or quarterly. This method is usually simpler, but stock mismatches, shortages, or stockouts may not be visible until the next physical count. For a clearer view of where it works best, refer to the comparison table below.

Perpetual Inventory System
In a perpetual inventory system, stock is updated after every purchase, sale, return, transfer, or adjustment. It gives businesses a more real-time view of inventory, but usually requires billing software, barcode scanning, POS integration, or inventory accounting software. The detailed comparison below explains when this system is more suitable.

Spreadsheet-Based Inventory Control

Spreadsheets can work for very small businesses, but they become risky as the number of SKUs grows. They are easy to edit, but difficult to audit. They also do not automatically connect purchases, sales, returns, stock valuation, and accounting entries .

Inventory Software

Inventory software helps businesses track purchases, sales, stock levels, item-wise movement, batch details, expiry details, reorder levels, and stock reports. When inventory software is connected with accounting, stock valuation, and financial reports become easier to reconcile.

BUSY's inventory management software connects billing, stock tracking, batch details, expiry dates, reorder levels, and accounting in one place, giving Indian SMBs a real-time view of stock without managing separate spreadsheets or registers. Whether you run a retail store, pharma distribution business, or FMCG operation, BUSY helps you stay GST-ready while keeping inventory accurate.

1. FIFO: First In, First Out

FIFO means older stock is sold or consumed first. It is useful for goods where older stock should not remain unsold for long. Under Ind AS 2 , FIFO is one of the accepted cost formulas for ordinary interchangeable inventory. It’s best for:

• FMCG
• Food items
• Medicines
• Cosmetics
• Perishable goods
• Items with batch or date sensitivity

2. FEFO: First Expiry, First Out

FEFO means the stock with the earliest expiry date is sold or used first. This method is more suitable than FIFO when the expiry date matters more than the purchase date. For example, if a medicine purchased later has an earlier expiry date, FEFO will push that batch first. It’s best suited for:

• Pharma
• Food products
• Packaged goods
• Cosmetics
• Chemicals

3. LIFO: Last In, First Out

LIFO means the newest stock is sold or consumed first. It may appear in inventory theory or some international costing discussions, but it should be handled carefully in Indian accounting content. In Indian financial reporting under Ind AS 2 , ordinary interchangeable inventory should be valued using FIFO or the weighted average cost method. LIFO is not listed as an accepted cost formula under Ind AS 2.

4. Weighted Average Cost

Weighted average cost works by taking the average price of similar items you’ve bought over a certain period or after each purchase, depending on your system. It’s a simple way to figure out what your inventory is really costing you. For Indian accounting (under Ind AS 2), this method is officially accepted for valuing everyday stock. It’s a good fit for:

• Items purchased frequently at different prices
• Commodities
• Raw materials
• Similar interchangeable goods

5. ABC Analysis

ABC analysis helps you focus on what matters most. It sorts your inventory into three groups: “A” items are high-value and require close attention, “B” items are important but less critical, and “C” items are lower-value and easier to manage. For example, a hardware distributor might stock 2,000 products, but just 200 of them (the A items) account for most of the value. These A items should be tracked more closely, reordered on time, and counted more often.

6. FSN Analysis

FSN stands for Fast-moving, Slow-moving, and Non-moving. This method shows you which products are selling fast, which are moving more slowly, and which are just sitting on the shelf. Retailers, distributors, and manufacturers use FSN analysis to identify items that tie up money and space. It helps you decide what to push, what to discount, and what to stop ordering.

7. VED Analysis

VED stands for Vital, Essential, and Desirable. It’s mainly used for spare parts, maintenance items, and materials that keep your business running. For example, a small machine part might be “Vital” if your entire production line stops without it. This method makes sure you never run out of the things you absolutely need.

8. Cycle Counting

Instead of doing one massive stock count at the end of the year, cycle counting means you regularly count a small group of items. This way, you catch mistakes sooner and don’t have to stop your whole business for a stocktake. For example, you can count “A” items every week or month, “B” items every quarter, and “C” items once or twice a year.

9. Just-in-Time

Just-in-Time (JIT) is about keeping as little stock as possible and ordering only when you really need it. This approach can save you money on storage, but it only works if you can rely on your suppliers and you have a good idea of customer demand. For many small and medium-sized businesses in India, pure JIT can be risky, so it’s often safer to use it alongside reorder points and a bit of safety stock.

Key Inventory Control Formulas

EOQ, or Economic Order Quantity, helps determine the optimal order quantity that balances ordering and holding costs . It’s formula is: 

EOQ = √(2 × D × S ÷ H)

Where:

• D = Annual demand in units
• S = Cost per order
• H = Annual holding cost per unit

Example: A stationery distributor sells 12,000 reams of paper per year. Each order costs ₹500 to process. Holding one ream costs ₹40 per year.

EOQ = √(2 × 12,000 × 500 ÷ 40)
EOQ = √300,000
EOQ = 548 units approximately

This means ordering around 548 units at a time may reduce the combined cost of ordering and holding stock.

2. Reorder Point

Reorder point tells you when to place a new order. It’s formula: 

ROP = (Average daily usage × Lead time in days) + Safety stock

Example: A pharmacy sells 50 units of a medicine per day. Supplier lead time is 6 days. Safety stock is 100 units.

ROP = (50 × 6) + 100
ROP = 400 units

When stock reaches 400 units, the next order should be placed.

3. Safety Stock

Safety stock is extra stock kept to handle demand spikes, supplier delays, or unexpected shortages. The simple formula is: 

Safety Stock = (Maximum daily usage × Maximum lead time) - (Average daily usage × Average lead time)

Example:

Average daily usage = 80 units
Maximum daily usage = 120 units
Average lead time = 7 days
Maximum lead time = 10 days

Safety Stock = (120 × 10) - (80 × 7)
Safety Stock = 1,200 - 560
Safety Stock = 640 units

This provides a more practical buffer because it accounts for both demand and lead time variation.

Note: Do not apply the same benchmark to every industry. A grocery store , an apparel shop, a spare parts dealer, and a machinery distributor will all have different stock movement patterns.

Inventory Control Best Practices

1. Create a clean item master

Avoid duplicate item names. Maintain proper SKU code, unit, tax rate, purchase price, selling price, category, supplier, batch details, and reorder level.

2. Set reorder levels for active items

Do not depend on memory. Set minimum and maximum stock levels, reorder point, and reorder quantity for important items.

3. Use FIFO or FEFO where needed

Use FIFO for older stock movement. Use FEFO where expiry matters. Train staff to place older or earlier-expiry stock in front.

4. Count stock regularly

 Use cycle counting instead of waiting for year-end. Count high-value and fast-moving items more frequently.

5. Track damaged, expired, and written-off stock separately

Do not mix these with normal sales . Separate tracking helps identify process gaps and improves stock accuracy.

6. Review dead stock every month or quarter

 Run an FSN report and check items with no movement for 90, 180, or 365 days, depending on your industry.

7. Connect inventory with accounting

When inventory and accounting are disconnected, stock valuation, gross margin , purchase cost, and GST records become difficult to reconcile. Integrated accounting and inventory software reduces this gap.

8. Maintain audit trail for stock changes

Stock adjustments should have a reason, date, user name, and approval where required. GST rules also recognize electronic records , but edited or deleted entries should be logged in the electronic record.

Use Cases by Industry

Retail

A retail store needs fast billing, barcode scanning, item-wise stock, low-stock alerts, and daily sales reports . ABC analysis helps identify the items that need tighter control.

Manufacturing

A manufacturer needs control over raw materials, work-in-progress, finished goods , scrap, wastage, and production-linked consumption. VED analysis is useful for machine spares and critical production items.

Pharma

A pharma distributor should use batch-wise and expiry-wise tracking. FEFO is important because medicines should be dispatched based on expiry priority. For APIs and top 300 drug formulation brands, CDSCO guidance refers to barcode or QR code requirements for traceability and authentication.

Food and FMCG

Food and FMCG businesses need FIFO, FEFO, expiry tracking, wastage entry, fast stock movement reports, and seasonal demand planning.

E-commerce

need live stock sync across platforms, return tracking, channel-wise stock, and SKU-level profitability. Without proper stock control, the same item may get oversold across multiple marketplaces.

Conclusion

Inventory control is the discipline of knowing what stock you have, where it is, how fast it is moving, when it should be reordered, and whether your records match physical reality.

For Indian SMBs, it is also closely linked with accounting and GST record keeping. A good inventory control process helps prevent stockouts, reduce dead stock, control wastage, improve cash flow, and maintain reliable business records.

The best approach is simple: maintain a clean item master, set reorder levels, follow FIFO or FEFO where relevant, count stock regularly, track shrinkage separately, review dead stock, and connect inventory with accounting software.