How to Forecast Inventory?

Virginia Miller
Virginia Miller
October 18, 2024
In this article

Whether a business sells its products through retail stores or online, lack of stocks to fulfill customers' orders or overstock more than the demand can lead to losses. Lack of inventory to fulfill orders damages the business's brand image apart from the losses incurred in issuing refunds. On the other hand, inventory levels exceed the demand locks in cash used to purchase or manufacture the inventory. There is a considerable risk of the inventory becoming dead stock. 

The inventory levels and the cash flow must be well aligned. To this end, inventory forecasting is imperative for any business enterprise, especially those dealing with large inventory volumes. 

What Is Inventory Forecasting?

Inventory forecasting is the process of estimating future demand for a product and calculating the necessary inventory to meet that demand. By forecasting inventory, businesses can ensure they have enough product on hand to fulfill orders without overstocking.

Key Factors in Forecasting Inventory

There are several key factors to consider when forecasting inventory:

  • Historical sales data
  • Market trends and seasonality
  • Competitor activity
  • Expected changes in customer demand
  • Current inventory levels
  • Outstanding purchase orders

Taking these factors into account allows businesses to estimate future demand more accurately and determine optimal inventory levels.

Benefits of Inventory Forecasting

Properly forecasting inventory levels provides several important benefits:

  • Prevents stockouts from unmet demand
  • Avoids costs from excess inventory
  • Optimizes use of warehouse storage space
  • Allows better planning of manufacturing/purchasing
  • Identifies fast/slow-moving products

Methods of Forecasting Inventory

There are several techniques businesses can use to forecast inventory:

  • Time series analysis - Uses historical data to identify trends and seasonal patterns
  • Causal / regression analysis - Quantifies relationship between demand drivers and sales
  • Qualitative forecasting - Uses expert input to predict changes in market conditions
  • Simulation modeling - Creates mathematical representations of demand patterns

The right forecasting methods depends on factors like product type, lead time, and amount of historical data.

Inventory Forecasting Enables Inventory Optimization

By accurately forecasting demand and inventory needs, businesses can optimize their inventory to meet customer needs while avoiding excess stock. This saves money while improving service levels. Overall, inventory forecasting provides vital insights for inventory planning and contributing to operational success.

Recommended: Maintaining Low Inventory Levels for Your Online Store

FAQs

What is inventory forecasting and why is it important?

Inventory forecasting predicts future demand for products to calculate necessary inventory levels. It prevents stockouts and excess stock, saving money while improving customer service.

What factors are used in forecasting inventory?

Key factors include historical sales data, market trends, competitor activity, expected demand changes, current inventory levels, outstanding orders, and more.

What are the benefits of accurate inventory forecasting?

Benefits include preventing stockouts, avoiding excess inventory costs, optimizing warehouse space, improving purchase planning, and identifying fast/slow products.

What methods can be used to forecast inventory?

Common methods include time series analysis of historical data, causal modeling, qualitative forecasting with expert input, and simulation modeling of demand.

How can you optimize inventory with forecasting?

By accurately forecasting demand, businesses can optimize inventory levels to meet customer needs and align with sales volumes cost-effectively.

What kind of data is used in inventory forecasting models?

Inventory forecasting models use historical sales data, pricing data, promotional calendars, inventory levels, competitor data, and qualitative market research.

Should you forecast inventory manually or use software tools?

Software tools are more efficient for frequent, accurate forecasting. But expert manual reviews also provide useful qualitative insights to refine the forecasts.

What happens if you don't forecast inventory properly?

Inaccurate forecasting can lead to stockouts and lost sales or excess inventory and carrying costs. It also reduces operational efficiency.