Plugins 〉SPC Chart
SPC Chart
SPC Chart
The SPC Chart panel automatically calculates and displays control limits for XmR, Xbar-R, and Xbar-S charts — so you can monitor process stability, detect special cause variation, and make data-driven decisions in real time.
Why SPC Chart?
Control charts are the foundation of statistical process control. They separate common cause variation (normal process behavior) from special cause variation (signals that something has changed). This plugin makes that analysis effortless:
- Automatic control limits — LCL, UCL, and Mean are calculated and displayed automatically based on the selected chart type
- Multiple chart types — XmR for individual measurements, Xbar-R for small subgroups, Xbar-S for larger subgroups
- Custom control lines — add Nominal, LSL, USL, or any custom reference line with static values or dynamic series lookup
- Fill regions — visually highlight zones between control lines to show acceptable process ranges
- Statistics table — an optional table below the chart summarizing each series: count, mean, standard deviation, min/max, control limits, and process capability (Cp, Cpk, Pp, Ppk)
Features
| Feature | Description |
|---|---|
| XmR charts | Individual (X) and Moving Range (mR) charts for single measurements |
| Xbar-R charts | Subgroup mean (X-bar) and Range (R) charts for small subgroups |
| Xbar-S charts | Subgroup mean (X-bar) and Standard Deviation (S) charts for larger subgroups |
| Automatic control limits | LCL, UCL, and Mean calculated from the data using standard SPC formulas |
| Custom control lines | Add Nominal, LSL, USL, or custom lines with static values or dynamic series lookup |
| Subgrouping | Group consecutive measurements into subgroups of size 2-25 |
| Aggregation | Aggregate raw data by moving range, range, mean, or standard deviation |
| Fill regions | Color-fill areas between control lines to highlight process zones |
| Alerting support | Grafana alerting integration with alert state annotations on the chart |
| Custom annotations | Create, edit, and delete annotations directly on the chart |
| Threshold visualization | Display alert thresholds alongside SPC control limits |
| Dashboard variables | Control subgroup size across multiple panels with a single subgroupSize variable |
| Feature queries | Exclude reference queries from SPC calculations |
| Statistics table | Optional summary table with per-series stats and process capability |
Statistics Table
Turn on Show statistics table in the panel options to display a summary table below the chart. For each series it shows the count, mean, standard deviation, min and max of your measurements, the control limits (LCL/UCL), and — when both a Lower and Upper Specification Limit are set — the process capability indices Cp, Cpk, Pp, and Ppk.
You choose which columns appear, and columns that don't apply are hidden automatically. To save the numbers, right-click the panel and choose "Download CSV". The table is off by default, so existing dashboards are unaffected until you enable it.
Use Cases
- Manufacturing quality — monitor process parameters and detect shifts before they produce defects
- IT operations — track response times, error rates, or throughput to distinguish real incidents from normal variation
- Laboratory analysis — control measurement systems and reagent performance over time
- Supply chain — monitor delivery times, fill rates, or inventory levels for process stability
- Healthcare — track clinical metrics and patient outcomes with statistical rigor
Requirements
- Grafana 11.6.10 or later
Getting Started
- Install the plugin from the Grafana Plugin Catalog
- Add a new panel and select SPC Chart as the visualization
- Configure a query that returns time series data (a time field and one or more numeric value fields)
- Select a Chart Type (XmR, Xbar-R, or Xbar-S) to automatically calculate control limits
The plugin comes with sample provisioned dashboards. Build and start the plugin to see them.
Documentation
For detailed documentation, configuration guides, and formula references, see the full documentation.
Part of the KensoBI SPC Suite
SPC Chart is part of a growing family of Statistical Process Control plugins for Grafana by Kenso Software:
SPC Histogram Panel — Distribution analysis with histograms, bell curves, and a built-in statistics table showing Cp, Cpk, Pp, and Ppk. Use it to understand process capability: is your process producing results within specification limits?
SPC Pareto Panel — Pareto analysis with automatic sorting, cumulative percentage lines, and 80/20 threshold highlighting. Use it to identify the vital few factors contributing to defects or issues.
SPC CAD Panel — Brings 3D geometry into the picture, letting you bind the data from control charts and histograms to physical features on your parts.
SPC Box Plot Panel — Box-and-whisker plots with built-in SPC. Automatically groups measurements into subgroups, computes quartiles and outliers, and overlays Xf-Rf control limits to detect shifts in both process location and spread.
SPC Bullet Panel — Compact bullet charts and progress bars with optional SPC metrics (Cpk, Cp, Ppk, Pp, Sigma Level) for dense KPI dashboards.
SPC Characteristic Datasource — The datasource that powers the SPC CAD panel. Connects to your measurement database (PostgreSQL or MSSQL), lets you select features and characteristics through a point-and-click interface, and returns SPC statistics, time series measurements, and forecast data — no SQL required.
Getting Help
If you have any questions or feedback, you can:
- Create an issue to report bugs, issues, and feature suggestions.
- Ask a question on the KensoBI Discord channel.
Your feedback is always welcome!
License
This software is distributed under the Apache License 2.0.
Grafana Cloud Free
- Free tier: Limited to 3 users
- Paid plans: $55 / user / month above included usage
- Access to all Enterprise Plugins
- Fully managed service (not available to self-manage)
Self-hosted Grafana Enterprise
- Access to all Enterprise plugins
- All Grafana Enterprise features
- Self-manage on your own infrastructure
Grafana Cloud Free
- Free tier: Limited to 3 users
- Paid plans: $55 / user / month above included usage
- Access to all Enterprise Plugins
- Fully managed service (not available to self-manage)
Self-hosted Grafana Enterprise
- Access to all Enterprise plugins
- All Grafana Enterprise features
- Self-manage on your own infrastructure
Grafana Cloud Free
- Free tier: Limited to 3 users
- Paid plans: $55 / user / month above included usage
- Access to all Enterprise Plugins
- Fully managed service (not available to self-manage)
Self-hosted Grafana Enterprise
- Access to all Enterprise plugins
- All Grafana Enterprise features
- Self-manage on your own infrastructure
Grafana Cloud Free
- Free tier: Limited to 3 users
- Paid plans: $55 / user / month above included usage
- Access to all Enterprise Plugins
- Fully managed service (not available to self-manage)
Self-hosted Grafana Enterprise
- Access to all Enterprise plugins
- All Grafana Enterprise features
- Self-manage on your own infrastructure
Grafana Cloud Free
- Free tier: Limited to 3 users
- Paid plans: $55 / user / month above included usage
- Access to all Enterprise Plugins
- Fully managed service (not available to self-manage)
Self-hosted Grafana Enterprise
- Access to all Enterprise plugins
- All Grafana Enterprise features
- Self-manage on your own infrastructure
Install on Grafana Cloud
Plugins can be installed directly from within your Grafana instance or automated using the Cloud API or Terraform.
Learn more about plugin installationMarketplace plugins
This is a paid plugin developed by a marketplace partner. To purchase an entitlement, sign in first, then fill out the contact form.
Get this plugin
This is a paid for plugin developed by a marketplace partner. To purchase entitlement please fill out the contact us form.
What to expect:
- Grafana Labs will reach out to discuss your needs
- Payment will be taken by Grafana Labs
- Once purchased the plugin will be available for you to install (cloud) or a signed version will be provided (on-premise)
Thank you! We will be in touch.
For more information, visit the docs on plugin installation.
Installing on a local Grafana:
For local instances, plugins are installed and updated via a simple CLI command. Plugins are not updated automatically, however you will be notified when updates are available right within your Grafana.
1. Install the Panel
Use the grafana-cli tool to install SPC Chart from the commandline:
grafana-cli plugins install The plugin will be installed into your grafana plugins directory; the default is /var/lib/grafana/plugins. More information on the cli tool.
Alternatively, you can manually download the .zip file for your architecture below and unpack it into your grafana plugins directory.
Alternatively, you can manually download the .zip file and unpack it into your grafana plugins directory.
2. Add the Panel to a Dashboard
Installed panels are available immediately in the Dashboards section in your Grafana main menu, and can be added like any other core panel in Grafana.
To see a list of installed panels, click the Plugins item in the main menu. Both core panels and installed panels will appear.
Changelog
2.3.0
New Features:
- Statistics Table: An optional table below the chart summarizing each series — number of measurements, mean, standard deviation, min/max, control limits (LCL/UCL), and process capability (Cp, Cpk, Pp, Ppk).
- Turned off by default, so existing dashboards look exactly the same until you enable "Show statistics table" in the panel options
- Choose which columns to display
- Capability values follow the Minitab convention: they are calculated from your raw measurements and your LSL/USL specification lines, so you get the same Cp/Cpk regardless of which chart of a pair (X̄ or R/S) you are viewing
- CSV Export: Right-click the panel and choose "Download CSV" (or use the download button on the statistics table) to export the statistics and control line values.
Calculation Accuracy Fixes:
After upgrading, some charts may show slightly different control limits than before. The new values are the correct ones:
- S chart: The lower control limit was calculated with an incorrect factor. If you use S charts, expect the LCL line to move to its correct position.
- Leftover measurements: When the data doesn't divide evenly into subgroups (for example 17 measurements with subgroup size 5), the leftover measurements no longer distort the center line and control limits. The last, smaller subgroup is still drawn as a point on the chart, but limits are estimated from complete subgroups only, so they may shift slightly compared to previous versions.
- Missing values: Gaps in the data were previously counted as the value 0, which could visibly skew subgroup averages, ranges, and standard deviations. Missing values are now ignored, and a subgroup with no usable measurements appears as a gap in the line.
- Too little data: When there aren't enough measurements to calculate control limits yet, the chart no longer draws limit lines in wrong places (such as at zero). The lines appear automatically once enough data arrives.
Security:
- Updated third-party components to address known vulnerabilities and added an automated vulnerability check to the release process.
2.2.0
New Features:
- Numeric X-axis Support: Added support for numeric X-axis to enable SPC charting for indexed/sequential data sources.
- New X-axis field selector allows switching between Time (default) and numeric fields
- Works similarly to Grafana's built-in Trend panel
- Perfect for analyzing data with sample numbers or sequence indices (e.g., 1, 2, 3...) instead of timestamps
- Multi-field Control Lines: Enhanced control line functionality for datasets with multiple numeric fields.
- Field selector for computed control lines (LCL, UCL, Mean) when multiple numeric fields exist
- Automatically hidden when only one numeric field is present to reduce UI complexity
- Enables proper SPC monitoring of multiple measurements in a single dataset
Compatibility:
- Maintains full backward compatibility with existing time-based SPC charts
2.1.1
New Features:
- Alerting Support: Support for Grafana alerting with alert states and annotations displayed on the chart.
- Alert states are now visualized directly on the chart
- Alert annotations show historical alert events on the timeline
- Create alerts based on SPC control limits (UCL, LCL) to detect out-of-control processes
- Annotation Support: Support for Grafana annotations with ability to create custom annotations directly on the chart.
Enhancements:
- Dependency Upgrades: Updated all dependencies to latest versions for improved security and performance.
Compatibility:
- Now supports React 19.
- Now supports Grafana 13.
2.0.2
New Features:
- Complete panel rewrite for improved performance and functionality.
- Added support for XmR chart creation.
- Added support for Custom Control Lines to pull dynamic values from Feature Series.
- Brand New SPC Editor: A completely redesigned editor for setting up and customizing SPC charts with an intuitive user interface.
- Threshold Colors: Ability to add color thresholds to every control line for better visualization.
- Multiple Series Support: Enhanced functionality to handle multiple data series.s
- Customization Options:
- Customization of legend, tooltip, axis, and graph styles.
- Introduced a subgroupSize dashboard variable to control subgroup size across multiple panels.
Enhancements:
- Improved SPC calculations: Enhanced accuracy in statistical process control.
Changes:
- License Update: Changed from Apache 2.0 to AGPL-3.0-only.
Compatibility:
- Now supports Grafana 11.
1.0.3 (2024-04-16)
Bug fixes
- Compatibility issue with Grafana 10.4.x (undefined reading 'Area') has been resolved.
- Bug with displaying colors in constants has been fixed.
Features and enhancements
- Ability to enter custom Sample size value has been added.
- New chart display styles: lines, smooth line, points, bars.
- Example demonstrating how to build a SQL query and use constants on a chart. See documentation for more information.
1.0.2 (2024-01-20)
- Fix scaling of panel options.
- Fix deprecated values.
- Add backward compatibility to Grafana >=9.5.7.
- Add ability to enter additional constants columns taken from the database using SQL entered as Table. See documentation for more information.
