Four inventory management metrics distributors are measuring and what they are highlighting

Inventory management has always been important for distributors but in the current environment defined by volatility and supply chain disruption – the numbers are showing some interesting signs.

Inventory is typically one of the largest assets on a distributor’s balance sheet. It represents both opportunity and risk. In a recent Phocas Inventory Trends in Wholesale Distribution report the four most measured inventory management metrics are:

1. Days Sales Inventory (DSI) or Days of Supply (DOS)
2. Cash conversion cycle (CCC)
3. Delivered in full, on time (DIFOT)
4. Gross margin return on inventory investment (GMROI)
   
   Each tells a different story. Together, they provide a strong picture of operational performance and financial health.

Metric 1: Days Sales Inventory (DSI)

Days sales inventory (AKA inventory days) measures how long distributors can continue meeting demand with the inventory they currently have.

DSI provides a forward-looking view of inventory coverage. It shows how many days inventory will last based on current sales. This metric helps distributors understand liquidity (or cashflow) and how efficiently stock is turning.

What DSI highlights

When DSI is low, inventory is turning quickly. Cash is not sitting idle and carrying costs are minimized. This is often ideal for fast-moving, high-volume products. When DSI is too low, the business can become vulnerable to sudden demand spikes.

When DSI is high, inventory sits longer. This may provide a buffer against volatility, but it also increases holding costs and ties up cash. High DSI can signal slow-moving SKUs, forecasting issues or purchasing decisions made in isolation.

Context is critical. Acceptable DSI varies widely across industries and product categories. A distributor carrying critical spare parts with long lead times may intentionally maintain higher DSI. A distributor handling perishable goods like food must keep DSI tightly controlled.

In the Phocas inventory trends in wholesale distribution report, 32% of respondents advised their DSI metric is between 60-90 days of supply and 22% carry more than 90 days. This trend towards holding more stock is directly related to distributors wanting to retain customers despite the holding costs of carrying more stock. “Being able to tell the customers ASAP we have the product makes the difference in orders” describes the sentiment of distributors at the current time. They want to do what they do best and that’s supply and retain customers. Other factors contributing to holding more stock include tariff uncertainty and an unreliable supply chain.

The power of DSI

Monitoring DSI helps distributors identify slow-moving or obsolete stock and improve forecasting accuracy. It also helps balance service levels with financial efficiency.

The real power of DSI comes from segmentation. Distributors that can analyze DSI by product category, supplier, warehouse and customer segment are able to differentiate between useful stock and problematic stock.

DSI is about aligning inventory levels with demand patterns and service commitments.

Metric 2: Cash conversion cycle (CCC)

The cash conversion cycle measures how long it takes for a distributor to convert cash invested in inventory back into cash collected from customers. Some finance teams explain the CCC as helping them determine how quickly cash flows through the business.

CCC connects inventory management with receivables and payables. It reflects operational efficiency, liquidity and financial processes.

What CCC highlights

A short CCC indicates that the company is moving inventory efficiently, collecting payments promptly and managing supplier terms effectively. Cash is recycled quickly, improving liquidity and reducing the need for external financing.

A long CCC suggests that capital is tied up in inventory or receivables for extended periods. This can strain cash flow, increase borrowing costs and reduce flexibility.

In distribution, inventory often represents the largest component of the cycle. Excess stock extends the time before cash is recovered and if the accounts receivable team are slow collecting money each month this can slow it down further.

In the recent Phocas Inventory Trends in Wholesale Distribution survey 30% of distributors operate in that moderate range of between 40 and 60 days, with 11% operating with fast conversion.

A strong CCC provides competitive advantage because distributors with efficient cash cycles can invest in improvements or new opportunities. What was evident from the survey was the lack of distributors that did not know the CCC, this could be because we surveyed some non-finance people, but it is a metric everyone working in a distribution business needs to know.

To improve CCC requires sales, purchasing and finance to work together with good data. It's also a great metric to share cross functionally so that people can see how their inventory decisions directly influence financial outcomes.

Metric 3: Delivered in full, on time (DIFOT)

Delivered in full, on time (DIFOT) measures how reliably a distributor fulfils customer orders — completely and on schedule. In today’s market, reliability is a differentiator for many distributors.

Customers expect consistent performance. They want the right products, in the right quantities delivered exactly when promised. A high DIFOT rate signals operational excellence. A low rate exposes weaknesses across inventory planning, warehouse management and transportation.

What DIFOT explains

A high DIFOT rate indicates strong demand forecasting and good customer communication. A low DIFOT rate reveals fundamental problems. Stockouts, packing errors, late shipments or inaccurate order processing may all be contributing factors.

DIFOT is often the first metric customers notice even if they don’t label it as such. When deliveries are inconsistent, trust erodes quickly.

Poor DIFOT performance has far reading ramifications for distributors’ reputation while strong DIFOT performance strengthens loyalty and drives repeat business.

DIFOT also ties directly to inventory strategy. Stockouts frequently cause ‘not in full’ problems. If certain SKUs consistently undermine DIFOT, that signals issues with demand planning or safety stock allocation.

By analyzing DIFOT alongside demand variability and product criticality, distributors can make better stocking decisions. The goal is to find the right balance so inventory protects service levels without tying up cashflow.

Metric 4: Gross margin return on inventory investment (GMROI)

While DSI and CCC focus on efficiency and cash flow, GMROI addresses profitability.

GMROI outlines for every dollar invested in inventory, it calculates how much gross margin is being generated.This metric helps distributors refine pricing strategies for every product and helps them to understand how competitive they can be in tenders and proposals.

What GMROI shows?

A high GMROI indicates that inventory is generating strong margins relative to its investment level. Products are turning well and contributing meaningfully to profitability.

A low GMROI signals that capital is tied up in items that are either slow-moving, low-margin or both. This represents an opportunity cost that capital could potentially generate higher returns elsewhere.

GMROI helps distributors look beyond revenue. High sales volume alone does not guarantee healthy performance if margins are thin and inventory sits too long.

For example, a product with modest sales volume but strong margin and healthy turns may outperform a high-revenue SKU that consumes excessive inventory investment.

GMROI also highlights imbalances across categories. Some segments may require strategic investment for market presence, while others should be optimized for profitability. It shifts the focus from sales to what product lines are profitable.

How these inventory metrics can work together

Each of these four metrics tells part of the story:

• Day sales of inventory reveals coverage and inventory turnover
• Cash conversion cycle shows how efficiently cash flows through operations
• Delivery in full on time measures customer-facing reliability
• Gross margin return on inventory investment evaluates profitability of inventory investment

When analyzed together, they provide powerful insights.

For example:

• High DSI + low GMROI may indicate excess stock in low-margin products.
• Low DSI + poor DIFOT could suggest understocking critical SKUs.
• Strong DIFOT + weak CCC may reveal excellent service levels funded by excessive working capital.
• Strong GMROI + poor DIFOT might indicate profitability achieved at the expense of customer reliability.

No single metric should drive decisions in isolation. Balanced performance across all four inventory metrics creates growth and customer loyalty.