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Days Sales in Inventory – What is DSI and Why is it Important?
10 min read

Days Sales in Inventory – What is DSI and Why is it Important?

Among the many invaluable performance metrics in inventory management, Days Sales in Inventory (DSI) stands out for its simplicity and straightforward insight into finding a balance between stock levels and sales.

What is days sales in inventory?

Days sales in inventory is an inventory metric that measures the average number of days a company takes to convert its inventory into revenue. Also referred to as Days in Inventory or Average Age of Inventory, DSI is a crucial key performance indicator (KPI) for gauging a company’s cash conversion cycle and understanding how efficiently it manages its stock.

Tracking DSI helps to highlight operational efficiencies and spot potential issues in production and sales. A low DSI value generally means that a company is balancing sales with inventory well. A higher DSI, on the other hand, may indicate low sales and a risk of overstocking. However, it might simply signify that a company is undergoing rapid growth as it increases stock in anticipation of customer demand surges.

Understanding DSI is important in gauging a company’s liquidity, overall inventory health, and profitability. It can be a simple yet invaluable means to arrive at more informed decisions on restocking.

Days sales in inventory vs inventory turnover ratio

DSI is closely related yet distinct from another important inventory management KPI – inventory turnover ratio. While DSI measures the average number of days it takes a company to sell its whole stock, the inventory turnover ratio KPI measures the number of times that stock is replenished over a time period.

While both KPIs pertain to converting inventory, they are inversely related – a lower DSI means a higher inventory turnover rate, and vice versa. Knowing the inventory turnover rate is also required to calculate DSI. Tracking both KPIs is useful as it can provide detailed insights for product lifecycle management, inventory optimization, pricing strategies, etc.

Continue reading about the inventory turnover ratio

How to calculate DSI?

As stated above, the first step in calculating DSI is to determine the inventory turnover rate. For this, we need to know the values of two other KPIs – average inventory and cost of goods sold.

The average inventory is a KPI signifying the estimated average value of inventory on hand at a given time. It’s calculated by summing up the beginning and ending inventory values for a given period and dividing them by 2.

Average inventory = (beginning inventory + ending inventory) / 2

The cost of goods sold (COGS) is another crucial accounting metric that designates the total cost of manufacturing all the finished goods that are sold within a fiscal period.

COGS can be calculated by summing the beginning finished goods inventory with the cost of goods manufactured (COGM) (or with simply procurements in the case of distributors), and then subtracting the ending finished goods inventory value.

COGS = beginning finished goods Inventory + COGM – ending finished goods inventory.

Check out our detailed blog post on how to calculate the cost of goods sold.

Once we know the average inventory and COGS values, we can find the inventory turnover ratio.

Inventory turnover ratio = cost of goods sold / average inventory

Days sales in inventory formula

Now that we know the other relevant KPIs, finding DSI is a simple matter of dividing the chosen time period by the inventory turnover rate:

Days Sales in Inventory = time period / inventory turnover rate

If we were to also include the aforementioned KPIs into the mix, the DSI formula would be:

Days Sales in Inventory = (average inventory / COGS) x time period

DSI example

Let’s look at an example. A furniture manufacturer has sold 240,000$ worth of goods in the last year. The company’s average inventory value amounted to 60,000$ for the time period. Knowing this, we can calculate the inventory turnover ratio for the manufacturer to be 240,000 / 60,000 = 4.

Next, we can calculate the Days Sales in Inventory by dividing 365 by 4, which comes out to be 91.25 days. With that, the manufacturer knows that on average, it goes through its inventory 4 times a year and it takes around 91 days to go through its entire stock.

The importance of days says sales in inventory

Understanding the DSI metric is crucial for effective inventory management and overall business health. Let’s look at key insights that tracking DSI can bring.

Demonstrating liquidity. DSI is a pivotal indicator of how long a company’s cash is tied up in inventory before it turns into sales. A lower DSI means the company converts its inventory into cash faster, advantageous for liquidity. Conversely, a higher DSI indicates that cash is tied up in unsold inventory for longer periods, straining finances. This extended cash conversion cycle can impact a company’s ability to meet immediate financial obligations, limiting flexibility to invest in opportunities or cover unexpected expenses.

Impact on cash flow predictions. By providing insights into the average time inventory remains unsold, DSI helps businesses predict their cash flow more accurately. If a business typically has a high DSI, it may need to plan for longer periods before cash from sales becomes available. This forecasting is critical for maintaining adequate cash reserves to sustain operations and avoid liquidity crunches.

Indicator for stockouts and overstocking. DSI can serve as an early warning system for potential stockouts or too-high inventory levels. A decreasing days sales of inventory might indicate that items are selling faster than usual, possibly leading to stockouts if not addressed promptly. On the other hand, an increasing DSI could suggest overstocking risk, which ties up capital and increases holding costs. By monitoring these trends, businesses can adjust procurement and production schedules to maintain optimal inventory levels.

Warehouse management. Understanding DSI also facilitates more effective warehouse management, as it helps plan the allocation and utilization of warehouse space. Knowing how long different items stay in inventory allows managers to strategize the placement of goods, prioritize faster-moving items, and potentially reduce storage costs. It also aids in identifying slow-moving goods that may need promotional efforts to increase their inventory ratio.

Influence on pricing strategies and performance. DSI can significantly inform pricing strategies and performance evaluations. For instance, products with a high DSI might be priced too high, deterring quick sales, or they might be out of season. Adjusting prices to increase the turnover rate can help reduce DSI, thereby improving cash flow and reducing holding costs. Furthermore, tracking DSI across different seasons helps businesses adapt their inventory and pricing strategies to seasonal demand variations, ensuring they maximize sales during peak periods and reduce excess inventory during off-peak times.

Determining a good DSI level

Identifying the optimal DSI level can be tricky as it varies across industries and individual business circumstances. Industry benchmarks are a good starting point as they reflect the normative turnover rates common to different sectors. For instance, industries dealing with perishable goods generally have lower DSI to prevent spoilage, whereas durable goods sectors like furniture may exhibit higher DSI due to slower sales cycles.

The stage of the business can also influence what constitutes a good DSI. New businesses might see higher days sales of inventory values as they fine-tune their inventory systems, while established ones often work towards reducing this metric to enhance cash flow efficiency. Companies facing high sales volatility might aim for a middle-ground DSI value to maintain enough inventory to handle demand surges without straining finances.

A company’s strategic goals should guide its DSI targets. Rapid growth strategies may necessitate higher DSIs to ensure product availability, whereas streamlining operations could push for lower DSI to increase profitability. Regularly comparing the value with industry standards, competitor levels, and historic averages can offer insights and help adjust strategies to optimize both operational efficiency and financial performance.

DSI and inventory management software

Effective inventory management is crucial for maintaining a healthy balance between supply and demand, directly impacting a business’s financial health and operational capabilities. Advanced inventory management software, particularly systems that incorporate material requirements planning (MRP) modules, significantly enhances this management by providing deeper insights and more precise control over stock levels.

Modern software solutions are designed to do much more than track inventory – they integrate various aspects of manufacturing and supply chain management, allowing businesses to anticipate demand and adjust production accordingly. This is invaluable as it helps companies predict how long their current inventory will last in real-time market conditions and plan future inventory needs more accurately.

By continuously monitoring DSI and other related KPIs, inventory management software provides a dynamic view of turnover trends. This enables companies to spot patterns or shifts in product movement that may indicate emerging market trends or internal process inefficiencies. For instance, a consistent increase in DSI might suggest that certain products are becoming less popular, prompting a business to adjust its production schedules or explore new market opportunities before overstocking becomes an issue.

In essence, modern cloud-based inventory management software is an indispensable tool for manufacturers in helping to streamline operations, improve cash flow, and maintain a healthy balance between stock levels and liquidity. By providing comprehensive tools to monitor and analyze stock levels in relation to market demand and production capacity, these systems support smarter, data-driven decisions that keep businesses lean and responsive in a fluctuating marketplace.

Key takeaways

  • Days Sales in Inventory (DSI) is a crucial metric that measures the average number of days a company takes to turn its inventory into sales, providing insight into how efficiently inventory is managed and how quickly it converts into revenue.
  • DSI is important as it highlights operational efficiencies and potential issues in production and sales processes. It indicates how long a company’s cash is tied up in inventory, impacting liquidity and financial flexibility.
  • To calculate DSI, determine the inventory turnover rate using the average inventory and the cost of goods sold (COGS). DSI is then calculated by dividing the time period by the inventory turnover rate, providing a clear measure of inventory duration.
  • A good DSI level depends on industry norms, the stage of the business, and strategic goals. It varies across different sectors and companies, requiring regular benchmarking against industry standards and competitors to determine the optimal DSI value.
  • Inventory management software that can track DSI enhances a company’s ability to monitor and analyze inventory efficiently. Such software integrates various aspects of business operations, providing dynamic views of inventory trends and helping to adjust production and sales strategies accordingly.

Frequently asked questions

How often should DSI be calculated for optimal inventory management?

For most businesses, calculating DSI every month is beneficial as it aligns with typical accounting periods and provides timely insights into inventory efficiency. However, the frequency can vary depending on the nature of the industry and specific business needs. High-volume businesses or those in fast-moving markets might benefit from weekly calculations, while industries with longer product lifecycles could find quarterly calculations sufficient. Regularly calculating DSI allows companies to respond proactively to market changes and maintain efficient inventory levels.

Can DSI vary by product line within the same company?

DSI can vary widely between different product lines within a company due to differences in market demand, production lead times, and sales strategies. To manage this variance, companies should segment their inventory and calculate DSI separately for each product line. This approach provides more precise data that can inform tailored strategies for each category, such as adjusting pricing, promotional efforts, or supply chain logistics to optimize overall inventory management and improve profitability.

What specific features should businesses look for in inventory management software to best track and utilize DSI?

When selecting inventory management software to track and utilize DSI effectively, businesses should look for features that offer real-time inventory and cost tracking, automated data analysis, and customizable reporting capabilities. The software should be able to integrate seamlessly with other systems such as sales, purchasing, and accounting to ensure that all relevant data is considered in DSI calculations. Additionally, advanced forecasting and planning tools like a Master Production Schedule can be particularly useful in maintaining optimal inventory levels and enhancing the decision-making process.

You might also like: 11 Most Important Inventory Management KPIs in 2024

Mattias MRPeasy
Mattias Turovski

Mattias is a content specialist with years of experience writing editorials, opinion pieces, and essays on a variety of topics. He is especially interested in environmental themes and his writing is often motivated by a passion to help entrepreneurs/manufacturers reduce waste and increase operational efficiencies. He has a highly informative writing style that does not sacrifice readability. Working closely with manufacturers on case studies and peering deeply into a plethora of manufacturing topics, Mattias always makes sure his writing is insightful and well-informed.

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