21 Techniques of Inventory Control to Improve Inventory Management Efficiency

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“Worldwide cost of inventory distortion (including shrinkage, stockouts, and overstock) is an estimated $1.1 Trillion.” –(IHL, 2015)

Inventory control refers to taking control of inventory activities. But it’s not enough to only take control. Controlling stock to keep optimal inventory levels is called Inventory Optimization.

So, inventory control and inventory optimization are correlated to each other, with the aim of ensuring the right amount of products in the right place at the right time as efficiently and cost-effectively as possible.

An effective inventory management process involves managing inventory visibility, inventory level, stock level, inventory cost, inventory turnover, excess inventory, inventory planning, obsolete inventory, inventory audit, inventory management technique, inventory management method, fulfillment, inventory control system, purchase order, finished product, and inventory count.

By implementing effective inventory management strategies, businesses can optimize inventory levels, reduce costs, improve customer satisfaction, and increase profitability.

Supply chain management plays a crucial role in effective inventory management, and businesses need to collaborate with suppliers, manufacturers, and distributors to ensure efficient and timely production and delivery of inventory.

Inventory Control vs Inventory Management:

Inventory control and inventory management are two related but distinct concepts in the field of inventory management.

Inventory control involves the processes and systems used to manage the movement and storage of inventory, with the aim of ensuring that the right amount of inventory is available at the right time, while minimizing costs and waste. This includes determining optimal inventory levels, setting up reorder points, managing safety stock, and tracking inventory movements.

On the other hand, inventory management encompasses a broader set of activities related to the planning, procurement, storage, and distribution of inventory. It includes both inventory control and other activities such as demand forecasting, inventory analysis, supplier management, and logistics management.

In short, inventory control focuses on the day-to-day management of inventory levels and movements, while inventory management involves the broader strategic planning and execution of inventory-related activities.

Inventory Control Strategies:

Two common strategies are used by successful businesses to control inventory:

The Pull Strategy: 

In a pull strategy, businesses purchase or manufacture products based on customers’ orders and deliver products within the delivery time. Here, the aim is to ensure product supply for customer demand.

By using a pull strategy in inventory management, businesses can reduce the risk of overproduction, minimize inventory holding costs, and increase customer satisfaction by ensuring that products are available when customers need them.

This approach requires a high level of coordination between all parties in the supply chain, including suppliers, manufacturers, and distributors, to ensure that inventory is produced and delivered in a timely and efficient manner.

The Push Strategy: 

A push strategy ensures inventory is based on predictive demand forecasting. Forecast expected demands according to demand forecasting rules, including historical data analysis, seasonality, trends, and factors that can affect future direction.

Under a push strategy, businesses try to maximize their production efficiency and economies of scale by producing large quantities of inventory and pushing it out to the market. This approach assumes that there will be demand for the products and that customers will buy them.

Push strategy can be useful for businesses that deal with fast-moving consumer goods, such as food and beverages, and seasonal products, where demand is predictable. However, it can also lead to overproduction and a surplus of unsold inventory, which can result in wastage and financial losses.

Comparison of Pull & Push Strategy:

Inventory Control Techniques:

In this article, we’ll look at 21 common inventory control techniques that will show you how to control your inventory (stock) levels, help you optimize stock, and maximize profits.

Different types of inventory control techniques are applied by business leaders based on business type, size, location, and demands.

Here are 21 effective inventory control techniques that you can apply, either individually or in combination, based on the demands of your business:

1. Demand Forecasting.

Demand forecasting has become a familiar inventory control technique for retailers and manufacturers. Demand forecasting estimates future demand based on historical sales data where the company expects customers will purchase according to estimate.

Remember, no predictions will be 100% perfect. But good predictions maximize potentials with minimal abilities.

The key to controlling your stock levels is predictive analytics from historical data. It’s critical to select and implement advanced inventory forecasting models that produce accurate demand forecasts. For small and medium-sized retailers and manufacturers, most of the time, there is no need to consider complex demand forecasting issues. It’s enough to follow historical sales patterns with some other factors like seasonality and trends.

Seasonality: Season is an essential factor in which demands may vary from season to season. It’s best practice to forecast the market based on previous seasons, as this makes the data more accurate for forecasting going forward.

Trends: Product demand is influenced by occasions, festivals, shifts in societal attitudes or values, technology, social, economic, and legal factors. Follow up on the trends and upcoming possibilities and adjust your forecasts accordingly.

Simple Implementation: For a defined period, analyze historical data and calculate safety stock and reorder point. Safety stock is the minimum stock quantity needed to avoid stock-outs based on demand. Reorder point is calculated from safety stock and lead time to ensure that the minimum stock quantity (safety stock) is maintained at any given moment. Reorder point is reached when a product’s stock quantity touches the reorder point, signaling the need to order more to ensure safety stock at all times.

Two Key Points of Demand Forecasting When Used as an Inventory Control Technique:

• Demand-driven replenishment (DDR) uses demand data to determine the right amount of inventory to order. This data can be collected from a variety of sources, such as sales data, customer surveys, and market research. DDR can help businesses to avoid overstocking and understocking, and it can also help them to improve their inventory accuracy.
• Continuous replenishment (CR) orders inventory on a continuous basis, rather than in batches. This can help businesses to reduce their inventory costs by avoiding the need to store large amounts of inventory. CR can also help businesses to improve their inventory accuracy by ensuring that they always have the right amount of inventory on hand.

2. ABC Analysis.

ABC analysis is an inventory control technique that categorizes inventory items based on their importance and profits. ABC inventory categorization follows the 80-20 rule where 80% (almost) of revenues come from 20% (almost) of items. This 20% of items are categorized as ‘A’ category. The next 30% of items are classified as ‘B’. And the bottom 50% of items are classified as ‘C’. This categorization helps business leaders understand which products or items are most important to the financial success of their business.

This ABC categorization technique splits items into three categories and controls inventories based on their importance:

• Category A is the most valuable product contributing to overall revenues.
• Category B is the products between the most and least valuable items.
• Category C is the least valuable item, vital for general business but doesn’t matter much individually.

3. Economic order quantity.

Economic order quantity (EOQ) is a formula for ordering an ideal quantity based on factors such as purchase costs, carrying cost, holding cost, production cost, demands, and other variables.

The primary objective of EOQ is to minimize related costs. The formula determines the optimized number of product quantities to minimize the cost of goods sold (COGS). This helps free up tied cash in inventory for most businesses.

This formula is effective when businesses benefit from rates for bulk purchases, carrying and holding costs are significant factors, and costs decrease dramatically for large-scale production.

EOQ = square root of: [2(demand)(order cost)] / holding costs.

4. VED Analysis.

VED Analysis is a popular inventory management strategy for small and medium-sized manufacturers where some raw materials are vital but not easy to restock quickly. This analysis helps to organize items for a production schedule.

According to their criticality, VED (Vital, Essential, and Desirable ) classifies materials into three Vital, Essential, and Desirable.

• Vital items: Vital items are required to continue the business. Without these items, business becomes a stand-still. It is suicidal to stock-out vital items. Some items will be crucial in your business, and you cannot compromise on stocks for them. Always maintain a safe amount of inventory of these.
• Essential items: Essential items are those whose stock-out cost would be very high. These items won’t shut your shop, but your customers will expect you to have them. After vital items, make sure enough stock of Essential items.
• Desirable items: These are good to have and may not directly affect your business. But they are adding more potential & opportunities. Maybe drops some sales due to stock-outs, but it is very nominal and easily recoverable.

5. Backordering.

A backorder is an order taken even if current stock is empty & takes steps like purchase (from a vendor) or production start against sales orders. i.e. take sales orders within a delivery time & purchase from a vendor or produce in the production process within the delivery time.

The nature of the backorder and the number of items on backorder will affect the time it takes before the customer eventually receives the ordered product. The higher the number of items back-ordered, the higher the demand for the item.

6. Dropshipping:

Dropshipping is a way to sell products online without having to keep any inventory. When a customer places an order, the seller simply contacts the supplier and the supplier ships the product directly to the customer. This means that the seller doesn’t have to worry about storing, packing, or shipping products, which can save a lot of time and money.

Dropshipping is a great way to start an online business because it’s relatively low-risk and low-investment. You don’t need to buy any inventory upfront, and you can start selling products right away. However, it’s important to choose reliable suppliers and to set up your business carefully to ensure that your customers have a good experience.

7. The Just In Time Strategy.

A Just-In-Time (JIT) inventory model ensures supply when needed to reduce locked capital and holding costs. When products are created based on a demanding schedule, it ensures raw materials are delivered to the production house directly. There is no need to store inventory in a warehouse for a long time. It ensures supplies are delivered when needed.

However, just-in-time inventory is no longer as widely used as it once was. This is because just-in-time inventory requires a high level of coordination between the business and its suppliers. If there is any disruption in the supply chain, it can lead to stockouts.

8. Just-in-Case Inventory Management.

Just-in-Case (JIC) inventory management is a strategy of keeping a large inventory on hand to reduce the risk of stockouts. This is in contrast to just-in-time (JIT) inventory management, which focuses on reducing inventory holding costs by ordering only the necessary inventory when it is needed.

JIC inventory management is often used by businesses that experience unpredictable demand or that have long lead times for their suppliers. It is also common in industries where stockouts can have serious consequences, such as the healthcare and food industries.

9. Vendor Managed Inventory.

Vendor Managed Inventory (VMI) is an inventory management model where a vendor, supplier, or manufacturer manages their seller’s or retailer’s inventory. Here the vendor takes full responsibility for maintaining inventory & inventory management decisions of their sellers or retailers based-on demands and other related factors.

Vendor-managed inventory (VMI) is a supply chain agreement where the upstream agent is responsible for the inventory of the downstream agent. This is also known as managed inventory, continuous replenishment program, or supplier-assisted inventory replenishment.

Vendor Managed Inventory works like below.

• The downstream agent’s data is shared with the upstream agent.
• Focus on demands, safety stocks, reorder points, and lead times.
• Vendors or suppliers or manufacturers manage supply and inventory.
• Continuously review the VMI system, identify improvements, and works together upstream and downstream agents.

10. Consignment Inventory.

If you’re like most small business owners, you probably don’t have a lot of extra cash sitting around to invest in inventory. That’s where consignment inventory can be a lifesaver.

Consignment inventory is inventory that is owned by someone else but is being stored at your business location. You generally only pay for the inventory once it’s sold, so it’s a great way to keep your inventory levels up without having to front the entire cost.

Of course, there are a few things to keep in mind if you’re considering consignment inventory for your business:

• You’ll need to have enough space to store the inventory.
• You’ll need to be comfortable with someone else’s inventory being stored on your premises.
• You’ll need to be sure that you have a sound system to track the inventory and sales.

11. Cross-Docking.

Cross-docking is a shipping method where products are delivered from suppliers directly to retail stores or to distribution centres for further distribution. This eliminates the need for warehousing and can help to reduce inventory levels and costs.

Cross-docking can be used for a variety of products but is most commonly used for perishable items or items that are time-sensitive. This shipping method can help to reduce spoilage and ensure that products are delivered fresh.

Cross-docking can be a beneficial shipping method for both retailers and suppliers. It can help to reduce costs and increase efficiency.

In a Cross-docking inventory management system, products are delivered from suppliers to directly retail stores or to distribution centres, eliminating middle-term warehousing and reduced inventory levels and costs.

12. FIFO and LIFO.

FIFO(First In First Out) means first-out(sales), the stocks which come first. First in, First out, ensures the older inventory is sold first. FIFO is an intelligent way to keep inventory fresh.

LIFO, or Last-in, First-out, means the newer inventory is sold first. LIFO helps prevent stock from going bad or expiring. Effective for food & beverage items where several stocks will be expired & damaged, customers get fresh items.

13. First Expire, First Out (FEFO):

First Expire, First Out (FEFO) is an inventory management technique that ensures that products with the shortest expiry dates are sold or used first. This is important for businesses that sell perishable goods, such as food and beverages, as well as for businesses that sell products with limited shelf lives, such as pharmaceuticals and cosmetics.

FEFO can be implemented in a number of ways, but the most common approach is to store products in chronological order, with the oldest products at the front of the shelf and the newest products at the back. This ensures that the oldest products are sold or used first, before they expire.

FEFO can be a complex inventory management system to implement and maintain, but it is essential for businesses that sell perishable goods. By using FEFO, businesses can reduce the amount of waste they produce and ensure that their customers receive fresh, high-quality products.

14. Batch Tracking:

Batch tracking refers to the process of monitoring and managing a collection of products or items that share common characteristics like a production date, lot number, or expiry date. These products are either manufactured together or received together.

The main objective of batch tracking is to enable businesses to keep a record of inventory movements and easily identify the specific batch of products in case of any quality issues, recalls, or regulatory requirements.

Batch tracking is extensively used in industries like food and beverage, pharmaceuticals, and electronics, where product traceability and quality control are of utmost importance.

15. FSN Analysis:

FSN analysis stands for Fast-Moving, Slow-Moving, and Non-Moving. It is a simple yet powerful inventory control technique used to categorize items based on their demand rate. This helps businesses prioritize their inventory efforts, allocate resources efficiently, and improve overall inventory performance.

Objectives of FSN Analysis:

• Identify and prioritize fast-moving items. These items require close monitoring, accurate forecasting, and frequent replenishment to avoid stockouts.
• Optimize inventory levels for each category, reducing holding costs for slow-moving and non-moving items.
• Establish appropriate ordering and replenishment policies based on the item’s classification. This may involve different ordering frequencies, order quantities, and safety stock levels.

16. HML Analysis:

HML analysis is a tool used in inventory management to categorize items based on their unit price. It helps businesses prioritize their inventory control efforts and allocate resources effectively. HML stands for:

• H: High-value items (highest unit price)
• M: Medium-value items
• L: Low-value items

The objectives of HML analysis are to:

1. Identify and prioritize high-value items. This ensures that these items are closely monitored and controlled, minimizing the risk of stockouts and losses.
2. Optimize inventory levels for each category, reducing holding costs and improving cash flow.
3. Establish appropriate ordering and replenishment policies based on the item’s classification.

17. SOS Analysis:

SOS Analysis, standing for Seasonal and Off-Seasonal, is a specific inventory control technique used for items with significant demand fluctuations based on seasonality. It helps businesses optimize their inventory levels, prevent stockouts during peak seasons, and avoid overstocking during off-seasons.

How SOS Analysis Works:

1. Identify Seasonal Items: Analyze historical sales data to identify items with significant demand fluctuations across seasons.
2. Classify Demand Patterns: Categorize seasonal patterns into distinct periods like peak season, off-season, and shoulder seasons.
3. Quantify Demand: Forecast demand for each season based on historical data, market trends, and promotional activities.
4. Set Inventory Levels: Determine the minimum and maximum stock levels for each season based on demand forecasts, lead times, and safety stock requirements.
5. Develop Ordering Strategies: Establish different ordering schedules and frequencies for each season based on demand fluctuations.
6. Implement Promotional Strategies: Utilize targeted promotions and discounts during off-seasons to stimulate sales and reduce inventory levels.
7. Monitor and Review: Regularly monitor inventory levels, sales data, and market trends to refine forecasts and adjust strategies as needed.

18. SDE Analysis:

SDE analysis, standing for Scarce, Difficult, and Easy, is a simple yet effective inventory control technique that categorizes items based on the availability of their supply. It helps businesses prioritize inventory control efforts, allocate resources efficiently, and improve overall inventory performance.

Objectives of SDE Analysis:

• Identify and prioritize scarce items: These items are challenging to obtain and require close monitoring and proactive management.
• Optimize inventory levels: Maintain sufficient stock of scarce items while minimizing holding costs for easy-to-source items.
• Establish appropriate ordering and replenishment policies: Adapt policies based on the difficulty of acquiring each item.
• Reduce inventory costs: Minimize procurement risks and costs associated with scarce items.

19. GOLF Analysis:

GOLF analysis stands for Government Supply, Ordinarily Available, Local Availability, and Foreign Source of Supply. It is a comprehensive inventory control technique that analyzes items based on their source of supply. This analysis helps businesses optimize procurement strategies, streamline inventory processes, and minimize costs associated with inventory management.

Objectives of GOLF Analysis:

• Identify and manage risks associated with different supply sources. This allows businesses to take proactive measures to mitigate risks and ensure the timely availability of inventory.
• Optimize procurement processes for each source of supply, considering factors like cost, lead time, and order quantity.
• Improve inventory visibility and control by tracking inventory levels and movement based on their source.
• Reduce procurement and inventory carrying costs by identifying and eliminating inefficiencies in the supply chain.

How GOLF Analysis Works:

1. Identify Inventory Items: List all items in your inventory.
2. Classify Inventory Sources: Categorize each item based on its source:
   • G: Government Supply
   • O: Ordinarily Available
   • L: Locally Available
   • F: Foreign Source of Supply
3. Analyze Each Source: For each source, consider factors such as:
   • Cost: Price per unit, potential discounts, transportation costs.
   • Lead Time: Time between placing an order and receiving the goods.
   • Order Quantity: Minimum order quantity, economic order quantity.
   • Payment Terms: Payment methods, credit periods, discounts.
   • Quality: Consistency and reliability of supplier quality.
   • Administrative Work: Documentation, communication, and other administrative tasks.
4. Develop Procurement Strategies: Based on the analysis, develop specific procurement strategies for each source. This may involve different ordering frequencies, order quantities, safety stock levels, and supplier selection criteria.
5. Monitor and Review: Regularly monitor and review the performance of each source to identify opportunities for improvement and adapt to changing circumstances.

20. XYZ Analysis:

XYZ analysis is a simple yet powerful inventory control technique that helps businesses classify inventory items based on their demand variability and forecast accuracy. By understanding the demand patterns of different items, businesses can allocate resources effectively, optimize inventory levels, and improve overall inventory performance.

 Divide items into three categories based on their CV:

• X (High Variability): High CV, indicating unpredictable demand and requiring close monitoring and frequent ordering.
• Y (Moderate Variability): Moderate CV, requiring some attention and possibly forecasting improvements.
• Z (Low Variability): Low CV, indicating predictable demand and allowing for less frequent ordering and lower safety stock levels.

Objectives:

1. Identify and prioritize inventory items: Focus attention on items with high demand variability and prioritize their control efforts.
2. Optimize inventory levels: Maintain sufficient stock to avoid stockouts while minimizing holding costs for items with low demand variability.
3. Establish appropriate ordering and replenishment policies: Implement different ordering frequencies, order quantities, and safety stock levels based on each item’s demand characteristics.
4. Improve forecasting accuracy: Identify items with unpredictable demand and invest in better forecasting methods for those items.

21. Customer Managed Inventory:

Customer Managed Inventory (CMI) is a supply chain management strategy where the customer, rather than the supplier, is responsible for managing their own inventory levels and placing replenishment orders. This approach differs from traditional inventory management, where the supplier holds the inventory and replenishes it based on forecasts or agreed-upon reorder points.

How CMI Works:

• Agreement: A supplier and customer establish a CMI agreement that outlines the responsibilities and expectations for both parties.
• Data Sharing: The supplier provides the customer with real-time inventory data and sales information.
• Forecasting and Ordering: The customer forecasts their demand and places orders with the supplier based on their own inventory levels and lead times.
• Replenishment: The supplier delivers the ordered goods to the customer.
• Monitoring and Reporting: Both parties monitor inventory levels and performance metrics to identify areas for improvement.

Inventory Control Mistakes:

Some mistakes worsen your inventory management, and your random activities lock up capital in unnecessary inventory and reduce profits.

1. Not Using Any Policy to Control Inventory.

Some business leaders are unaware of inventory management or fail to use any policies to manage their inventory. They operate randomly, which often leads to excess stock, deadstock, and stockouts. This can increase holding costs, operational costs, and tie up capital in unnecessary inventory items.

Sometimes, business leaders ignore these factors because they are still making a profit. However, they are also ignoring opportunities to maximize their profits, which could increase dramatically with just a simple inventory control software.

2. Choosing the Wrong Techniques.

From the above inventory management techniques, choose the perfect one for your business according to your business type, size, & policies. Historical Demand Forecasting is ideal for most retailers & manufacturers where safety stock and reorder points continually update depending on demands.

The next effective inventory control model is ABC categorization, where 20% of items are in the ‘A’ category, which generates most of the revenues. The next 30% of items are in the ‘B’ category, and the rest 50% of items are in the ‘C’ category. The inventory manager follows the categories of the items and ensures availability according to their importance.

Economic order quantity is an effective model where bulk purchase gives a big discount, and holding, carrying, and operational cost is a big factor of COGS(Cost of Goods Sold).

The rest inventory control models like VED analysis, Backorder, Vendor Managed Inventory, FIFO, and LIFO all are popular and effective inventory control models based on business category, strategy & policy.

Types of Inventory Control Systems:

Businesses use three major inventory management systems based on their demands. These are 1. manual inventory, 2. periodic inventory, and 3. perpetual inventory. Manual methods are and least accurate, and perpetual systems are the most sophisticated and most accurate.

1. Manual Inventory System: 

Using pens & paper or a spreadsheet to manage and record inventory data. Most of the time, small businesses use manual systems. It’s hard to manage & track your inventory in the manual system when you have data or paper, and the processor is your brain.

2. Periodic Inventory System: 

In a periodic inventory system, inventory is counted periodically in a preferred time frame. Physically counts items and records item details, including move in and out of stock. Records are kept in a database like stock levels and locations.

3. Perpetual Inventory System: 

Perpetual inventory system is a real-time data tracking system. When stock is in the entry, it and stock data are updated automatically. All modern inventory management software that follows this system includes bar code software.

Best Practices for Inventory Control:

Here are some of the best practices for inventory control:

1. Set clear goals for inventory control: What do you hope to achieve by implementing inventory control? Do you want to reduce costs, improve customer service, or both?
2. Choose the right inventory control system for your business: There are a variety of inventory control systems available, so it’s important to choose one that’s right for your business. Consider your size, industry, and budget when making your decision.
3. Track your inventory levels closely: This will help you to identify when you need to order more inventory and avoid stockouts.
4. Set reorder points: A reorder point is the level of inventory at which you should order more inventory. This will help you to ensure that you always have enough inventory on hand to meet demand.
5. Monitor your inventory costs: Inventory costs can be a significant expense for businesses, so it’s important to monitor them closely. By tracking your inventory costs, you can identify areas where you can reduce costs.
6. Review your inventory control system regularly: As your business grows and changes, you may need to adjust your inventory control system. Make sure to review your system regularly to ensure that it’s still meeting your needs.

By following these best practices, you can implement an effective inventory control system that will help you to improve your business.

Technologies Used to Control Inventory:

Barcode, QR code and RFID are three standard technologies used to control inventory. Different businesses use different ones based on their demands.

Barcode.

Barcodes are machine-readable code in the form of numbers and parallel lines of varying widths that are printed on products, labels, or packaging to identify the item for sale or distribution. Barcodes can be read by optical scanners called barcode readers or scanned from an image by special software.

Barcodes are used to track inventory, prices, and product information.

Barcodes are a convenient way to keep track of products and inventory. They can be read quickly and accurately by barcode scanners and can be used to track product information, prices, and inventory levels.

Barcodes are a convenient and efficient way to track products and inventory. By using barcodes, businesses can save time, manpower, and cost.

QR code.

A QR code is a machine-readable code containing a product id(SKU) in inventory management software represented by an image consisting of an array of black and white squares used for managing inventory operations.

A QR code (Quick Response code) is a two-dimensional barcode that stores information. QR codes are becoming more popular for inventory management. QR scanners and smartphone cameras can read QR codes.

QR codes can be added to printed materials, such as inventory levels or invoices. When a QR code is scanned, inventory management software displays the product information or invoice details.

RFID.

RFID is a cutting-edge technological innovation that is being used in various industries and applications. This technology uses radio waves to identify and track inventory levels. RFID has many potential benefits, including improved efficiency, security, and accuracy. In addition, RFID tags are often much smaller and more durable than traditional barcodes, making them ideal for a wide range of applications.

In Summary:

In today’s business landscape, it is essential to leverage modern technologies to stay ahead of the competition. By doing so, businesses can improve their services, reduce costs, increase profitability, and ultimately achieve sustainable growth.

To achieve optimal inventory control, businesses must employ modern inventory management techniques. These techniques can help businesses keep track of their inventory levels and make informed decisions about when to order more stock, how much to order, and where to store it. This can lead to significant cost savings, improved customer satisfaction, and increased profitability.

There are several inventory control methods available, and businesses must choose the most suitable ones based on their unique needs and requirements. For example, businesses can use an inventory control system to track stock levels and automate the ordering process. This can help reduce errors and save time, ultimately leading to more efficient operations.

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