Visualizing Success: Leveraging Minitab's Graphical Capabilities for Inventory Optimization

Jon Finerty | 03 July, 2023

Topics: Control Charts, Minitab Statistical Software, Supply Chain, Pareto Charts

Effective inventory management plays a critical role in ensuring smooth operations, reducing costs, and meeting customer demands for supply chain managers. To achieve optimal inventory levels, it is essential to have a robust monitoring and control system in place. In this blog, we will explore the practical applications of Minitab's graphical tools, such as Pareto charts, control charts, and scatter plots, and how they can provide valuable insights into inventory patterns, leading to more efficient and effective decision-making processes.

Unleash the Power of Pareto Charts

A Pareto chart is a special type of bar chart where the plotted values are arranged from largest to smallest. Pareto charts are used to identify and prioritize the most significant factors or issues affecting a particular outcome. Applied to inventory management, it implies that a significant portion of issues and costs can be traced back to a few critical items or categories. By focusing efforts on these "vital few", supply chain managers can maximize their impact on inventory optimization. 


When analyzing Pareto charts, here are some important factors to consider: 

  • Identify the Vital Few: Identify the items or categories that contribute the most to inventory issues, such as stockouts, excess inventory, or high lead times. These critical few should become the primary focus for improvement efforts. 

  • Set Improvement Priorities: Based on the Pareto chart, determine the areas that can deliver the greatest impact on inventory optimization. Allocate resources and prioritize initiatives accordingly. 

  • Drill Down into Root Causes: Once the vital few are identified, investigate the underlying causes contributing to their high impact. Conduct root cause analysis to uncover factors such as inaccurate demand forecasting, supplier performance issues, or process inefficiencies. 

  • Develop Action Plans: With a clear understanding of the critical issues and their root causes, develop targeted action plans to address them. Collaborate with relevant stakeholders, such as suppliers, sales teams, and production personnel, to implement the necessary changes and improvements.

Download a free trial of Minitab Statistical Software to start visualizing your supply chain data today! 

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Keep Processes Under Control with Control Charts

Control charts are statistical tools that provide a visual representation of process variation over time. They help identify when a process is in control (stable) or out of control (exhibiting unexpected variation). By monitoring key inventory metrics using control charts, supply chain managers can proactively identify and address inventory-related issues, such as stockouts, excess inventory, or irregular demand patterns. 

Here are some key points to consider when analyzing control charts: 

  • Identifying Out-of-Control Signals: Monitor the control chart for any data points that fall outside the control limits or exhibit unusual patterns. These signals indicate that the process is out of control and requires investigation to identify the underlying causes. 

  • Investigating Root Causes: When out-of-control signals are detected, conduct a thorough analysis to identify the root causes of the inventory issues. This may involve examining factors such as supplier performance, process inefficiencies, inaccurate demand forecasting, or inadequate inventory policies. 

  • Taking Corrective Actions: Based on the analysis, develop and implement appropriate corrective actions to bring the inventory management process back under control. Collaborate with cross-functional teams, including suppliers, sales, and operations, to address the identified root causes effectively. 

  • Monitoring and Continuous Improvement: Continuously monitor the control charts to ensure that the implemented corrective actions have been successful in bringing the process back into control. Regularly update and analyze the control charts to identify any emerging trends or issues that may require further attention. 

Control Chart!

Minitab offers rare control charts, such Time Between Events (T chart) and Geometric Moving Average (G chart). These charts can be used to monitor and control certain aspects of inventory management, such as tracking lead times, analyzing replenishment patterns, monitoring inventory performance indicators, and detecting process variability. Using these charts, supply chain managers can make data-driven decisions to optimize inventory levels and enhance overall supply chain performance.

Learn how to choose the right Control Chart based on your data type in this blog post.


Unveil Relationships with Scatter Plots

Scatter plots provide a valuable tool for analyzing relationships between different variables, such as demand and inventory levels. Supply chain managers can utilize scatter plots to optimize inventory in the following ways:

  • Identifying Patterns and Trends: Examine the scatter plot for any noticeable patterns, such as clusters, trends, or outliers. These patterns can reveal relationships between the variables and provide insights into inventory dynamics. 

  • Assessing Correlations: Use Minitab's correlation coefficient feature to quantify the strength and direction of the relationship between the variables. A positive correlation suggests that as one variable increases, the other also tends to increase, while a negative correlation indicates an inverse relationship. 

  • Identifying Influential Factors: Identify the inventory factors that have a significant impact on others. These influential factors can guide decision-making regarding inventory optimization strategies. For example, if a strong positive correlation is found between demand volume and stockouts, increasing inventory levels during periods of high demand may be warranted. 

  • Performing What-If Analyses: Minitab allows you to explore different scenarios by manipulating variables within the scatter plot. This enables supply chain managers to assess the potential impact of changes in inventory factors, such as adjusting lead times or implementing alternative sourcing strategies.

Scatterplot of Units Sold vs Unit Price

Visualize Trends and Seasonality with Time Series Plots

Time series plots are used to visualize and analyze how a variable or a set of variables changes and evolves over a specific time period. Using time series plots, supply chain managers can: 

  • Forecast Future Demand: By applying forecasting techniques and models to the time series data, managers can generate reliable predictions of future demand patterns. These forecasts serve as a foundation for optimizing inventory by ensuring adequate stock levels to meet anticipated customer demand while minimizing excess inventory or stockouts.
  • Manage Seasonal Fluctuations: By analyzing the plot, managers can observe recurring patterns and adjust inventory levels accordingly. Understanding seasonality allows managers to plan for increased demand during peak seasons, adjust safety stock levels, and optimize replenishment strategies to avoid stockouts or excessive inventory. 

  • Monitor Inventory Performance: By comparing actual inventory levels to desired targets or forecasts, managers can assess the accuracy of their inventory plans and make necessary adjustments. Monitoring inventory performance allows for continuous improvement and ensures that inventory levels are optimized to meet customer demands while minimizing costs. 

  • Identify Outliers and Anomalies: Time series plots help managers identify outliers or anomalies in inventory data that deviate from expected patterns. These outliers may indicate sudden spikes or drops in demand, supply disruptions, or other irregularities. By identifying and investigating these anomalies, managers can take corrective actions to optimize inventory levels, mitigate risks, and improve overall supply chain performance. 


Minitab's graphical capabilities empower supply chain managers to unlock valuable insights from their inventory data. By utilizing visual representations such as Pareto charts, control charts, scatter plots, and time series plots, managers can gain a deeper understanding of inventory patterns, identify root causes of issues, forecast demand accurately, and optimize inventory levels for improved efficiency. Embracing Minitab's graphical tools allows supply chain professionals to make data-driven decisions, driving success in inventory optimization and ultimately enhancing the overall supply chain performance.

Ready to gain deeper insights into your supply chain data? See how easy it can be with Minitab's Supply Chain Module!

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