Make AI-Driven Inventory Optimization an Ally for Your Organization
In this blog, we will explore how organizations can achieve exceptional efficiency and accuracy with AI-driven inventory optimization. Traditional inventory management methods often fall short due to their reactive nature and reliance on manual processes. Maintaining optimal inventory levels is fundamental for meeting customer demand while minimizing costs. The introduction of AI-driven inventory optimization can significantly reduce the burden of manual processes, providing relief to supply chain managers from tedious tasks. With AI, we can predict demand more accurately, reduce excess stock, avoid stockouts, and ultimately improve our organization’s bottom line. Let’s explore how this approach not only boosts sales and operational efficiency but also elevates customer satisfaction by ensuring products are always available when needed.

 

Insights for Improved Decision-Making in Inventory Management

  1. Enhanced Forecast Accuracy Advanced Machine Learning algorithms analyze historical data to identify patterns that humans might miss. Techniques like clustering, regime change detection, anomaly detection, and regression analysis provide deep insights into data. Measuring forecast error is essential for refining forecast models; for example, techniques like Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE) help quantify the accuracy of forecasts. Businesses can improve accuracy by continuously monitoring and adjusting forecasts based on these error metrics. As the Demand Planner at a Hardware Retailer stated, “With the improvements to our forecasts and inventory planning that Smart Software enabled, we have been able to reduce safety stock by 20% while also reducing stock-outs by 35%.”
  1. Real-Time Data Analysis State-of-the-art systems can process vast amounts of data in real time, allowing businesses to adjust their inventory levels dynamically based on current demand trends and market conditions. Anomaly detection algorithms can automatically identify and correct sudden spikes or drops in demand, ensuring that the forecasts remain accurate. A notable success story comes from Smart IP&O, which enabled one company to reduce inventory by 20% while maintaining service levels by continuously analyzing real-time data and adjusting forecasts accordingly. FedEx Tech’s Manager of Materials highlighted, “Whatever the request, we need to meet our next-day service commitment – Smart enables us to risk adjust our inventory to be sure we have the products and parts on hand to achieve the service levels our customers require.”
  1. Improved Supply Chain Efficiency Intelligent technology platforms can optimize the entire supply chain, from procurement to distribution, by predicting lead times and optimizing order quantities. This reduces the risk of overstocking and understocking. For instance, using forecast-based inventory management, Smart Software helped a manufacturer streamline its supply chain, reducing lead times by 15% and enhancing overall efficiency. The VP of Operations at Procon Pump stated, “One of the things I like about this new tool… is that I can evaluate the consequences of inventory stocking decisions before I implement them.”
  1. Enhanced Decision-Making AI provides actionable insights and recommendations, enabling managers to make informed decisions. This includes identifying slow-moving items, forecasting future demand, and optimizing stock levels. Regression analysis, for example, can relate sales to external variables like seasonality or economic indicators, providing a deeper understanding of demand drivers. One of Smart Software’s clients reported a significant improvement in decision-making processes, resulting in a 30% increase in service levels while reducing excess inventory by 15%. “Smart IP&O enabled us to model demand at each stocking location and, using service level-driven planning, determine how much to stock to achieve the service level we require,” noted the Purchasing Manager at Seneca Companies.
  1. Cost Reduction By optimizing inventory levels, businesses can reduce holding costs and minimize losses from obsolete or expired products. AI-driven systems also reduce the need for manual inventory checks, saving time and labor costs. A recent case study shows how implementing Inventory Planning & Optimization (IP&O) was accomplished within 90 days of project start. Over the ensuing six months, IP&O enabled the adjustment of stocking parameters for several thousand items, resulting in inventory reductions of $9.0 million while sustaining target service levels.

 

By leveraging advanced algorithms and real-time data analysis, businesses can maintain optimal inventory levels and enhance their overall supply chain performance. Inventory Planning & Optimization (IP&O) is a powerful tool that can help your organization achieve these goals. Incorporating state-of-the-art inventory optimization into your organization can lead to significant improvements in efficiency, cost reduction, and customer satisfaction.

 

 

Managing Inventory amid Regime Change

​If you hear the phrase “regime change” on the news, you immediately think of some fraught geopolitical event. Statisticians use the phrase differently, in a way that has high relevance for demand planning and inventory optimization. This blog is about “regime change” in the statistical sense, meaning a major change in the character of the demand for an inventory item.

An item’s demand history is the fuel that powers demand planners’ forecasting machines. In general, the more fuel the better, giving us a better fix on the average level, the volatility, the size and frequency of any spikes, the shape of any seasonality pattern, and the size and direction of any trend.

But there is one big exception to the rule that “more data is better data.” If there is a major shift in your world and new demand doesn’t look like old demand, then old data become dangerous.

Modern software can make accurate forecasts of item demand and suggest wise choices for inventory parameters like reorder points and order quantities. But the validity of these calculations depends on the relevance of the data used in their calculation. Old data from an old regime no longer reflect current reality, so including them in calculations creates forecast error for demand planners and either excess stock or unacceptable stockout rates for inventory planners.

That said, if you were to endure a recent regime change and throw out the obsolete data, you would have a lot less data to work with. This has its own costs, because all the estimates computed from the data would have greater statistical uncertainty even though they would be less biased. In this case, your calculations would have to rely more heavily on a blend of statistical analysis and your own expert judgement.

At this point, you may ask “How can I know if and when there has been a regime change?” If you’ve been on the job for a while and are comfortable looking at timeplots of item demand, you will generally recognize regime change when you see it, at least if it’s not too subtle. Figure 1 shows some real-world examples that are obvious.

Figure 1 Four examples of regime change in real-world item demand

Figure 1: Four examples of regime change in real-world item demand

 

Unfortunately, less obvious changes can still have significant effects. Moreover, most of our customers are too busy to manually review all the items they manage even once per quarter. When you get beyond, say, 100 items, the task of eyeballing all those time series becomes onerous. Fortunately, software can do a good job of continuously monitoring demand for tens of thousands of items and alerting you to any items that may need your attention. Then too, you can arrange for the software to not only detect regime change but also automatically exclude from its calculations all data collected before the most recent regime change, if any. In other words, you can get both automatic warning of regime change and automatic protection from regime change.

For more on the basics of regime change, see our previous blog on the topic: https://smartcorp.com/blog/demandplanningregimechange/  

 

An Example with Numbers in It

If you would like to learn more, read on to see a numerical example of how much regime change can alter the calculation of a reorder point for a critical spare part. Here is a scenario to illustrate the point.

Scenario

  • Goal: calculate the reorder point needed to control the risk of stockout while waiting for replenishment. Assume the target stockout risk is 5%.
  • Assume the item has intermittent daily demand, with many days of zero demand.
  • Assume daily demand has a Poisson distribution with an average of 1.0 units per day.
  • Assume the replenishment lead time is always 30 days.
  • The lead time demand will be random, so it will have a probability distribution and the reorder point will be the 95th percentile of the distribution.
  • Assume the effect of regime change is to either raise or lower the mean daily demand.
  • Assume there is one year of daily data available for estimating the mean daily unit demand.

 

Figure 2 Example of change in mean demand and sample of random daily demand

Figure 2 Example of change in mean demand and sample of random daily demand

 

Figure 2 shows one form of this scenario. The top panel shows that the average daily demand increases from 1.0 to 1.5 after 270 days. The bottom panel shows one way that a year’s worth of daily demand might appear. (At this point, you may be feeling that calculating all this stuff is complicated, even for what turns out to be a simplified scenario. That is why we have software!)

Analysis

Successful calculation of the proper reorder point will depend on when regime change happens and how big a change occurs. We simulated regime changes of various sizes at various times within a 365 day period. Around a base demand of 1.0 units per day, we studied shifts in demand (“shift”) of ±25% and ±50% as well as a no change reference case. We located the time of the change (“t.break”) at 90, 180, and 270 days. In each case, we computed two estimates of the reorder point: The “ideal” value given perfect knowledge of the average demand in the new regime (“ROP.true”), and the estimated value of mean demand computed by ignoring the regime change and using all the demand data for the past year (“ROP.all”).

Table 1 shows the estimates of the reorder point computed over 100 simulations. The center block is the reference case, in which there is no change in the daily demand, which remains fixed at 1 unit per day. The colored block at the bottom is the most extreme increasing scenario, with demand increasing to 1.5 units/day either one-third, one-half, or two-thirds of the way through the year.

We can draw several conclusions from these simulations.

ROP.true: The correct choice for reorder point increases or decreases according to the change in mean demand after the regime change. The relationship is not a simple linear one: the table spans a 600% range of demand levels (0.25 to 1.50) but a 467% range of reorder points (from 12 to 56).

ROP.all: Ignoring the regime change can lead to gross overestimates of the reorder point when demand drops and gross underestimates when demand increases.  As we would expect, the later the regime change, the worse the error. For example, if demand increases from 1.0 to 1.5 units per day two-thirds of the way through the year without being noticed, the calculated reorder point of 43 units would fall 13 units short of where it should be.

A word of caution: Table 1 shows that basing the calculations of reorder points using only data from after a regime change will usually get the right answer. What it doesn’t show is that the estimates can be unstable if there is very little demand history after the change. Therefore, in practice, you should wait to react to the regime change until a decent number of observations have accumulated in the new regime. This might mean using all the demand history, both pre- and post-change, until, say, 60 or 90 days of history have accumulated before ignoring pre-change data.

 

Table 1 Correct and Estimated Reorder Points for different regime change scenarios

Table 1 Correct and Estimated Reorder Points for different regime change scenarios