Inventory control best practices: Transform procurement into a strategic function

Poor inventory control costs your organization twice: once when excess capital sits idle in surplus stock, and again when customer demand spikes unexpectedly and stockouts halt projects and force emergency orders at premium prices.
 

If you're a technology leader managing procurement for growing organizations, you know that modernizing inventory processes is necessary but risky. Change too much at once, and you disrupt operations. Wait too long and inefficiency compounds.
 

This guide provides practical strategies for modernizing inventory control step by step. You'll find specific methods, systems, and best practices you can implement without disrupting existing workflows. The goal is to balance operational efficiency with cost management by moving procurement from reactive ordering to strategic planning.
 

Key takeaways

• Automate inventory control by integrating with your existing ERP and procurement systems to reduce manual work, buying errors, and stockouts.

• Pilot with high-value categories first. You can show ROI in weeks through cost savings, faster order cycles, and reduced carrying costs.

• Centralized inventory data surfaces tail spend, enforces policies, and flags supply chain risks before they become operational crises.

• Simplified workflows integrated with the systems your teams already use drive faster adoption without the overhead of change management.
   

What is inventory control?

Inventory control is how you decide what to stock, how much to hold, and when to replenish. It bases purchasing decisions on actual operational needs, not habit.
 

Without inventory control, procurement can be forced to operate reactively. Capital gets tied up in slow-moving stock, and projects stall when critical items run out. These bottlenecks can compound quickly, eroding cash flow.
 

U.S. Census data confirms the payoff: the inventory-to-sales ratio dropped from 1.39 in February 2025 to 1.33 in February 2026. That tightening ratio reflects companies holding less idle stock relative to sales, which signals that tighter inventory control is becoming the standard.
 

Types of inventory control approaches

There are four main approaches to choose from to track and manage inventory. The right one depends on your operational complexity, budget, and visibility needs.
 

• Manual tracking: Physical inventory counts and handwritten logs work for very small operations, but they're prone to error and don't scale.

• Stock cards: A physical record for each item tracking receipts, issues, and balances. Useful as a transition tool, but can't provide real-time visibility for data-driven purchasing.

• Spreadsheet-based systems: Flexible and familiar, but can create version control headaches and don't connect inventory to actual purchasing patterns.

• Inventory management software: Integrates with your ERP and procurement tools to automate tracking and provide real-time visibility. Essential when managing high-value items or rapid growth.
   

These approaches aren’t mutually exclusive. These approaches aren’t mutually exclusive. For example, many organizations start with spreadsheets and migrate to software as complexity increases, but if you’re managing high-value items or multiple inventory locations, software is worth the upfront investment. Whereas stock cards or a hybrid approach may hold up longer for a stable, low-SKU environment.
 

Periodic vs. perpetual systems

Once you’ve identified your inventory tracking approach, your next decision is how your system updates: continuously or on a schedule. Perpetual systems update records continuously, while periodic systems rely on scheduled counts. 
 

Your choice directly impacts data accuracy, operational agility, and the resources required to maintain effective supply chain efficiency. If your inventory moves fast, involves high-value items, or requires real-time visibility to make procurement decisions, perpetual systems are the stronger fit. Periodic systems tend to work best when transaction volume is low and scheduled counts align with your reporting cycles.
 

Perpetual inventory control system

A perpetual inventory control system continuously tracks stock levels, updating records automatically with every transaction, whether that's a purchase, return, or transfer. Barcode scanners, radio frequency identification (RFID) tags, and integrated software create a digital trail of every item as it moves through your organization.
 

• Benefits: Accurate, real-time data that supports better purchasing decisions and prevents both stockouts and excess inventory. Perpetual systems also reduce the labor required to maintain them, and discrepancies from theft, damage, or data entry errors surface immediately rather than weeks later.

• Drawbacks: Implementation requires upfront investment in hardware, software, and integration work. Staff training is essential, and system downtime introduces operational risk, making redundancy planning important.

• Essential technology components: Barcode systems are the most common tracking method, offering a cost-effective balance of accuracy and ease of use. RFID technology provides greater automation by scanning multiple items simultaneously without line-of-sight requirements, but costs more.
   

Periodic inventory control system

A periodic inventory control system operates on a scheduled counting cycle (typically monthly, quarterly, or annually) rather than tracking stock levels continuously. Between counts, you rely on purchase records and sales data to estimate inventory levels. This approach calculates ending inventory using the formula:
 

• Beginning Inventory + Purchases - Cost of Goods Sold = Ending Inventory

• Benefits: Lower implementation costs, reduced administrative burden between counts, and simplicity for stable environments with low transaction volumes.

• Drawbacks: Limited visibility means you won't quickly discover stockouts or shrinkage until the next scheduled count. Physical counts are labor-intensive and prone to human error as inventory complexity grows.

• Essential elements: Scheduled counting cycles, purchase records, sales data, and manual reconciliation processes.
   

8 inventory control methods

Different inventory scenarios call for different approaches. Some methods rely on mathematical formulas to optimize order quantities. Others use visual systems to trigger replenishment. 
 

You'll likely use multiple methods across different inventory categories, including sophisticated approaches for high-value items, or simpler techniques for routine supplies.
 

1. Economic order quantity (EOQ) and reorder point calculations

EOQ identifies the order size that minimizes total inventory costs by balancing ordering expenses against holding costs. The formula is:
 

EOQ = √(2DS/H)
 

Where D is annual demand, S is cost per order, and H is annual holding cost per unit. This identifies the optimal order quantity, eliminating both overstock and frequent small orders. 
 

Reorder point calculations work alongside EOQ by triggering purchases when inventory hits a predetermined threshold, accounting for lead time and demand variability. This method works best when demand is predictable and suppliers are reliable.
 

2. Just-in-time (JIT) and lean inventory approaches

Just-in-time (JIT) minimizes inventory holding by synchronizing deliveries with actual consumption, reducing storage costs and warehouse space requirements. This approach requires reliable suppliers, accurate demand forecasting, and supply chain management coordination.
 

JIT improves cash flow and reduces waste, but increases vulnerability to supply disruptions. Technology organizations adopt modified JIT approaches that maintain strategic buffers for critical components while applying lean principles to commodity items.
 

3. First-in, first-out (FIFO) and last-in, first-out (LIFO)

First-in, first-out (FIFO) moves older inventory out before newer stock, critical for perishable items, products with expiration dates or spoilage risk, or technology components subject to obsolescence.
 

Last-in, first-out LIFO assumes the most recently acquired items are sold first, primarily an accounting method used in some US industries.
 

Note that LIFO is not permitted under International Financial Reporting Standards (IFRS). For technology organizations managing physical inventory, FIFO aligns with product lifecycle realities and provides clearer visibility into inventory age.
 

4. Min-max to control stock levels

The min-max method establishes minimum and maximum inventory thresholds for each item. When stock falls to the minimum level, you reorder enough to reach the maximum quantity.
 

It simplifies inventory management when you have numerous SKUs, letting procurement teams set parameters once and automate reordering. Revisit thresholds periodically as business conditions change.
 

5. Two- and three-bin systems

These visual methods use physical separation to trigger reorders. In a two-bin system, you draw from one bin while keeping a second as a reserve; when the first empties, you reorder while using the reserve.
 

Three-bin systems add an extra buffer for security during supply disruptions. These methods excel in manufacturing facilities, maintenance operations, or IT hardware stockrooms, requiring minimal training and technology investment.
 

6. Fixed order quantity and fixed period ordering

Fixed order quantity means you always order the same amount when inventory reaches the reorder point, regardless of timing. This is useful for high-value items where price stability matters.
 

Fixed period ordering establishes regular review intervals when you assess inventory levels and place variable-quantity orders. It suits teams that benefit from consolidated shipments or predictable procurement cycles. You can combine both approaches across different inventory categories.
 

7. Vendor-managed inventory (VMI)

Vendor-managed inventory (VMI) shifts inventory monitoring and replenishment responsibility to your supplier, who tracks consumption and automatically restocks based on agreed parameters. This reduces administrative burden and taps supplier expertise in demand forecasting. 
 

VMI works best for high-volume, predictable items, but requires robust contractual agreements, data transparency, and systems integration. Start with a single supplier for non-critical items before expanding.
 

For organizations already using Amazon Business, our Restock service (a separate managed service available in select US cities) handles automatic replenishment of office supplies, safety equipment, and IT consumables without requiring a supplier contract or manual reordering. It’s a lower lift option for predictable, recurring supplies where full VMI is more infrastructure than you need.
 

8. Set par levels

Par level inventory control establishes standard quantities for each item based on typical consumption patterns and desired service levels. When inventory falls below par, you reorder to restore the standard level.
 

This method reduces decision fatigue by automating the reorder decision. Par levels work best with predictable, consistent demand and require adjustment when technology needs fluctuate due to project cycles or rapid growth.
 

6 inventory control best practices

Implementing inventory control methods is necessary, but practices help you operationalize them effectively. Effective procurement planning combines these methods with actionable best practices.
 

1. Buy based on need, not habit

Many organizations order the same quantities at the same intervals out of habit. This disconnects procurement from actual demand, and can result in excess slow-moving inventory and stockouts of critical items.
 

Demand forecasting analyzes historical usage patterns, seasonal trends, and business growth projections to predict future inventory needs. Combined with calculated reorder points, your procurement team knows when to place orders based on actual consumption rates. The Reorder Point (ROP) formula provides a systematic framework:
 

ROP = (Average Daily Usage × Lead Time in Days) + Safety Stock
 

If your team uses 50 units daily, your supplier's lead time is 10 days, and you maintain a 100-unit safety buffer, your reorder point is 600 units.
 

ABC analysis prioritizes inventory by value and impact:
 

• A items (20% of items, 80% of value) require tight control and frequent review

• B items (30% of items, 15% of value) require regular but less frequent review

• C items (50% of items, 5% of value) require minimal oversight
   

2. Maintain stock for critical items

Safety stock protects operations when demand spikes unexpectedly or suppliers miss deadlines.
 

Calculate safety stock using supplier lead time variability and your target fill rate. If a supplier consistently delivers within 5-7 days, your buffer should be leaner than for a supplier with a 3-15 day variance. Track fill rate performance and revisit safety stock calculations whenever supplier performance changes.
 

3. Track supplier KPIs

Inventory control is only as strong as your suppliers. Tracking performance gives you early warning before a reliability issue becomes a stockout and also gives you the data you need to build strategic supplier partnerships. Establish a consistent measurement framework across these critical dimensions:
 

• On-time delivery rate: The percentage of orders delivered within the agreed-upon time, directly impacting your ability to maintain optimal stock levels and reduce buffer stock.

• Lead time variance: The consistency of delivery timing compared to quoted lead times, helping you refine reorder points and reduce buffer stock.

• Defect rate: The percentage of items requiring return or replacement, affecting inventory accuracy and operational efficiency.

• Fill rate: The percentage of ordered quantity actually delivered, revealing supplier capacity constraints before disruptions.

• Contract compliance: Adherence to negotiated pricing, terms, and service level agreements that protect your procurement budget and operational predictability.
   

Establish quarterly supplier scorecards that track these KPIs over time, creating visibility into performance trends rather than isolated incidents. This view helps you distinguish between temporary disruptions and systemic issues that warrant supplier diversification.
 

4. Establish purchasing procedures

Standardized purchasing procedures prevent maverick spend and ensure inventory decisions align with your policies. Without clear workflows, sophisticated systems can't prevent unauthorized purchases that create stock imbalances and budget overruns.
 

Amazon Business enables procurement teams to implement Guided Buying, a feature that lets you set approval workflows, spending limits, and purchasing restrictions based on user roles and business rules. 
 

You can configure multi-level approval chains that route purchase requests to the right stakeholders based on dollar thresholds, product categories, or departmental budgets.
 

Business Lists further support procedural consistency by creating curated collections of approved products that you can share across teams. Building lists of pre-approved items for specific departments or use cases reduces the time teams spend searching for products and ensures they select items that meet quality and inventory standards.
 

5. Centralize inventory data

Fragmented inventory data creates blind spots that lead to duplicate orders, stockouts, and wasted capital.
 

Centralizing inventory data consolidates information from all sources into a unified view, giving procurement, operations, and finance access to accurate, real-time information. This eliminates discrepancies from separate records and reveals opportunities to consolidate purchases and negotiate better terms.
 

Start by conducting audits of where inventory data currently exists. Then establish data governance protocols that define the authoritative source for each data type, sync frequency between systems, and accountability for accuracy.
 

6. Implement real-time inventory systems

Real-time inventory visibility catches discrepancies as they happen, not weeks later during physical counts. These systems continuously update records with each transaction, giving you an accurate view of stock on hand and enabling informed restocking decisions.
 

Beyond preventing out of stock situations, real-time systems help procurement reduce excess and obsolete inventory by surfacing slow-moving items quickly, before capital gets tied up in unsellable stock. Real-time visibility is a cornerstone of supply chain efficiency.
 

How to track inventory control ROI

Demonstrating ROI is essential for securing leadership buy-in on inventory control improvements.
 

1. Carrying costs: The total expense of holding inventory, including storage, insurance, obsolescence, and opportunity cost of tied-up capital.

2. Inventory turnover rate: Divide cost of goods sold by average inventory value. Higher turnover means you're moving stock efficiently without over-purchasing.

3. Stockout frequency: How often critical items are unavailable when needed. Each stockout causes delays and expedited shipping costs.
    

Days of Inventory Outstanding (DIO) provides a powerful efficiency benchmark. Divide average inventory by cost of goods sold, then multiply by 365. This metric shows how many days of inventory you're holding. Lower DIO means faster cash conversion and reduced carrying costs.
 

Compare your metrics against procurement benchmarks to understand how you're performing relative to peer organizations.
 

Amazon Business Analytics (included with Business Prime) provides visibility into purchasing patterns, spend concentration, and reorder frequency for purchases made through Amazon Business. That data helps you spot consolidation opportunities and flag when purchasing behavior drifts from your inventory policies.
 

Improve your inventory control today

You don't need to overhaul your entire inventory control system overnight. Start with one area: establish reorder points for critical items, implement approval workflows to reduce maverick spend, or gain visibility into purchasing patterns across departments.
 

Amazon Business provides procurement capabilities that complement your inventory control efforts. Through purchasing analytics and spend tracking, you gain visibility into what your teams are buying and when. Guided Buying and Business Lists help standardize purchasing around preferred items and suppliers. 
 

For routine consumables and office or safety supplies, Amazon Business Restock (a managed service available in select US cities) automates replenishment so procurement teams don’t need to manually reorder predictable items.
 

See how Amazon Business can help you streamline inventory control and keep your operations running smoothly.