Inventory is an asset on a company’s books. Every unit has economic value, so the company needs firm control over it. Above all, the stock shown in the books, meaning the system stock, must match the physical stock in the warehouse.
When the two match and the stock itself is the right mix and quantity, we say the inventory is healthy. When they drift apart, or when the warehouse is full of the wrong items, inventory health suffers, and so do sales, costs and profits.
Why Inventory Health Matters
Holding inventory is a must for any business that makes, sells or trades products. But inventory ties up working capital, so it must be kept at the optimum level at all times.
- Too much inventory erodes profits and raises carrying costs, which pushes up operating costs.
- Too little inventory leads to lost sales, lost revenue and damage to the company’s reputation with customers.
Inventory is also operations-intensive. With thousands of items and many daily transactions, it can quickly go out of control without tight processes. The result is pilferage, damage, theft and shrinkage.
Items with special needs, such as perishable goods, products with a shelf life, temperature-controlled goods or tilt-sensitive items, need an even closer watch.
Why System Stock and Physical Stock Drift Apart
Most inventories run into thousands of stock-keeping units (SKUs). Raw material and spare parts inventories often have far more SKUs than finished goods, and even finished goods such as clothing or groceries can run into thousands.
Inventory management works on two levels at once: transactions and data in the system, and physical processes on the ground. Both must move in step, so that every transaction is completed both in the system and on the floor.
A Typical Day in the Warehouse
- Receiving: Materials arrive from vendors and are unloaded, counted and entered in the system.
- GRN and put-away: The system issues a goods received note (GRN) and directs where the material should be stored.
- Storage confirmation: Staff move the material to the location and confirm it in the system, which closes the transaction.
- Picking: For outgoing orders, the system releases pick lists. Staff pick the items and confirm back to the system.
- Packing and invoicing: The system releases a packing order and an invoice for the shipment.
- Internal moves: Bin-to-bin transfers, kitting and similar tasks are done physically and confirmed in the system.
With so many linked transactions running in parallel, a single process deviation can create a gap between system and physical stock.
The Extra Layer of Outsourcing
Many companies outsource warehousing to third-party service providers. This multiplies the transactions, because a second system is added.
The principal customer keeps its inventory in its enterprise resource planning (ERP) system. The provider runs its own warehouse management system (WMS). Both systems must stay in sync with each other and with the physical operations on the floor.
ERP and WMS: Where Things Go Wrong
How the Two Systems Talk
ERP and WMS are usually linked through standard interfaces. They exchange files in batches, often every 30 or 60 minutes.
- Goods received at the warehouse are recorded in the WMS, which sends GRN details to the client’s ERP.
- The ERP processes orders based on its own stock figures and sends sales orders to the WMS.
- The WMS creates pick waves. Once confirmed, it releases the packing list and invoice.
- The WMS then sends dispatch details back to the ERP.
Because updates are not real-time and hundreds of transactions run concurrently, gaps can appear. That is why the two systems, and the physical stock, must be reconciled daily.
System Discipline
Transaction-based systems demand strict discipline from users. Every process must be completed without shortcuts, and masters must be kept up to date.
For example, if a consignment is blocked and must not be dispatched, it must be blocked in both the WMS and the ERP. If it is blocked only in the WMS, the ERP may still show it as available and allocate it to a sales order. The order then reaches the warehouse, where the stock cannot be picked, and the customer’s delivery is held up.
Master Data Must Be in Sync
SKU codes change often, and the same item may come from several vendors under different codes. Every time a new SKU is created in the client’s ERP, the same SKU must be created in the WMS.
SKU codes, descriptions, other SKU details and vendor master data in the WMS must mirror the ERP. If this coordination fails, stock gets mixed up or does not upload into the system at all.
Location Accuracy
The system shows exactly which SKU and how many units sit in each location. On the floor, each location must hold that exact SKU and quantity.
If staff put stock in the wrong location, it causes havoc in both the system and operations: pickers cannot find stock that the system says is there.
| Cause of Mismatch | Example | How to Prevent It |
|---|---|---|
| Delayed system updates | Batch interface runs hourly; stock sells before the update | Daily reconciliation of ERP, WMS and physical stock |
| Incomplete transactions | Put-away done but not confirmed in the system | Scan-based confirmation for every task |
| One-sided blocks | Stock blocked in WMS but open in ERP | Block and release in both systems together |
| Master data gaps | New SKU created in ERP but not in WMS | Joint master data process with sign-off |
| Wrong location | Pallet stored in a bin other than the one assigned | Location scans and daily cycle counts |
| Poor system design | Cumbersome screens lead staff to bypass the system | Design the system around the real business process |
What Causes Inventory Inefficiency?
Inventory reduction drives almost always deliver visible savings and release cash. Does that mean inventory management is usually inefficient? The answer is both yes and no.
Inventory depends on physical operations across many locations, agencies and processes. Transactions happen in sequence and in parallel, so over time inefficiencies creep in through operations, transactions and documentation.
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Poor System Setup
Another common cause is the system itself. Often the system setup is cumbersome and not user-friendly.
An efficient system should guide both the physical process and the documentation, and it should be built around the business process. In many cases, however, operations are forced to fit an existing, basic system that does not suit the business.
When the system does not match the warehouse setup, users complain of missing features, long and cumbersome steps, missing reports, and loops and bugs. Staff then find shortcuts to bypass the system. The result is inefficient operations and inaccurate inventory.
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A “Necessary Evil” Mindset
Inventory health also depends on the company’s strategy and outlook.
Some companies treat inventory as a necessary evil. They make sure processes are compliant and audits happen, but they do not treat inventory as an important asset to be reviewed and kept lean.
Other companies understand the benefits of lean inventory. They benchmark their practices against the best in the industry and keep improving, because every efficiency gain adds to profits.
A Company’s Strategic Approach to Inventory Health
Effective inventory control rests on two pillars: the company’s inventory strategy and policy, and management’s focus on day-to-day inventory operations.
Companies that see supply chain and inventory policy as a source of competitive advantage invest in efficient supply chain models and practices. HP, IBM, Dell, Walmart, Xerox, Procter & Gamble and Unilever are well-known examples. They have continually reviewed and re-engineered their inventory and supply chain strategies.
Many of these companies moved away from traditional storage models toward Vendor Managed Inventory (VMI), Just-in-Time (JIT) supply and Efficient Consumer Response (ECR). Their suppliers hold stock close to their plants and deliver just in time.
Retailers, in a highly competitive market, have invested heavily in software for stock visibility and replenishment. System-driven catalog management, statistical forecasting and data analysis have brought lean inventory to these companies and contributed to their market success.
Strategy alone is not enough, though. Its success depends on ground operations, especially when stock sits at many locations run by third parties. As the owner of the inventory, the company should:
- Build a strong inventory and logistics team with the right experience
- Define processes and set clear expectations for every site
- Gather MIS data, analyze it and control through checks and balances
- Deploy systems that can produce the reports the business needs
- Set up independent audit teams to check books, systems and processes for both operational and statutory compliance
- Focus on internal inventory planning, not just on monitoring the 3PL provider
Good Inventory Management Practices
Good practices keep inventory under control and lean, neither too much nor too little. Often, management ignores inventory until a cost-cutting drive exposes years of hidden problems. Companies that treat inventory as a core function avoid this.
Inventory management is both a management and an operations function. It requires disciplined floor processes and system processes, plus continuous analysis and decision-making.
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Review Stock Norms Regularly
Many companies apply one stocking policy to all items. For example, all A, B and C category items may carry 15 days of stock.
This rarely fits. Lead times differ from item to item, and past data often shows very different demand patterns and “hit frequency.” Applying the same norm to every item leads to overstocking of slow movers and shortages of fast movers.
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Plan in Detail: One Size Does Not Fit All
Understand the characteristics of each item you carry and set stocking parameters to match.
- Some items are expensive and may need to be stocked for longer.
- Some have short lead times and move fast.
- Some have a shelf life and need their own norms and closer attention.
Sometimes the best answer is not to stock an item at all, but to agree a delivery time with customers based on how often it is ordered.
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Study Demand Patterns and Cycles
Businesses with large inventories, especially in retail, must review and clean up their item lists continuously. This is known as catalog management.
Stock norms should be reviewed using sales data, demand patterns and business cycles. In retail clothing, for example, certain SKUs become redundant every season, however well they sold before. This review shows which items need micro-level management and which high-value, fast-moving items must always be watched to avoid stock-outs.
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Match Stock to Value and Availability
Carrying the same stock level for low-value and high-value items does not make sense.
- If low-value items are available locally with short lead times, cut their stock and change the buying pattern.
- For high-value items, reduce inventory by shortening delivery lead times.
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Flush Out Dead Stock
Study past data regularly to identify slow-moving and obsolete items. Dispose of dead stock quickly and keep the active catalog available.
Measuring Inventory Health
A company should define clear metrics for both inventory health and inventory operations health, and senior management should review them regularly with the operating team.
| Metric | What It Measures | Typical Target |
|---|---|---|
| Inventory record accuracy | Share of SKUs where system and physical stock match | 98% or higher |
| Location accuracy | Share of locations holding the right SKU and quantity | 99% or higher |
| Inventory turnover | How many times stock is sold and replaced in a year | Higher is better; varies by industry |
| Days of inventory on hand | How many days current stock will last | In line with the stocking norm for each category |
| Slow-moving and obsolete stock | Value of stock with little or no movement | As low as possible; reviewed monthly |
| Stock-out rate | Share of orders that could not be filled from stock | As low as possible for key items |
Decisions to scrap or dispose of unwanted, unused and non-moving stock should be made quickly, in line with changes in demand. This keeps inventory balanced and efficient.
A Simple Daily Reconciliation Routine
Whether the warehouse is run in-house or by a 3PL, the company’s ERP and the warehouse system should be reconciled every day:
- Download the day’s transactions from both the ERP and the WMS: receipts, dispatches and stock adjustments.
- Compare closing stock for every item. Any item whose balances differ goes on an exception list.
- Trace the missing step. For each exception, check whether goods were put away but not confirmed in the system, or packed and shipped but not yet posted. Fix the root cause, not just the number.
- Compare cycle count results with system stock and correct locations.
- Correct both systems together. Never adjust stock in only one system. Post matching corrections in both the ERP and the WMS, with a supervisor’s approval.
- Report exceptions to the central inventory desk and management.
Conclusion
Inventory management is ongoing and dynamic. Keeping inefficiencies out of systems, processes and physical operations needs active management involvement and continuous improvement.
Key decisions, such as how much inventory to carry and who in the supply chain should own it, drive efficiency. Technology can speed up sales and delivery and reduce manpower costs. But in the end, healthy inventory comes from disciplined processes, accurate systems and a management team that treats inventory as money.
Frequently Asked Questions
What is inventory health?
It is the condition of a company’s inventory in terms of accuracy (system stock matching physical stock) and balance (the right items in the right quantities, with little dead stock).
Why does system inventory not match physical inventory?
Common causes are delayed or incomplete system updates, stock stored in wrong locations, master data gaps between systems, and staff bypassing the system.
What is the difference between ERP and WMS?
ERP is the company’s overall business system for orders, finance and inventory. WMS is a specialized system that runs warehouse operations such as receiving, put-away and picking.
What are good inventory management practices?
Review stock norms regularly, set norms item by item, study demand patterns, match stock levels to value and availability, and dispose of dead stock quickly.
How often should inventory be reconciled?
Transactions between systems and physical stock should be reconciled daily, backed by cycle counts and periodic full counts.
