Feature request: stacked grouped mixed chart

[beliaev-maksim]

Business requirement specification based on #28181

Request

We need a bar chart that supports both grouping and stacking simultaneously. The X-axis should handle arbitrary data or time series. Additionally, the chart must support a mixed format (e.g., bar + line overlay) and include trend lines.

Example Use Case:

We currently track the ratio of User Stories delivered in Sprint N to Bugs opened in Sprint N (split by P1 and P2/P3). An efficiency line (#User Stories / #Bugs Open) helps visualize team performance, while a trend line for P1 bugs highlights patterns over time.

This is critical for maintaining product quality as we scale. As technical debt grows, bug influx can impact efficiency. Tracking these metrics ensures we maintain high standards while keeping the product competitive.

Google Sheet implementation

Example of implementation using Google Sheet: https://docs.google.com/spreadsheets/d/1G3rntcOYkf9Uwz4yBHDFOsfgV87RT0UMh15HbxTXlh4/edit?usp=sharing

The chart groups User Stories (blue bars) and Bugs (red + yellow bars) by Agile sprints. At the same time, Bugs are stacked to show priority levels (red for Priority 1, yellow for Priority 2/3).

The green line represents efficiency across sprints, while the light red line is an automatically calculated trend line for Priority 1 Bugs.

[rusackas]

Moving this to an Ideas thread since we're open to a PR for this, but not considering it a bug. If you don't have resources do develop this, feel free to bring others to this thread, and/or reach out to me on Slack for some channel pointers.

[jpchev]

hi there, I need this feature, I am available to help to develop, but I need some guidance.

It seems echarts already supports the feature through the parameter 'stack', which is used to group the bars (series with the same stack value will be stacked together)

[rusackas]

Oh, glad to hear ECharts supports it! Probably all that's needed then are some changes to the transformProps file in that plugin to feed the dimension(s) to the right eCharts attribute. And some changes to the control panel, to feed it. One option would be rather than just a single Dimensions input, we could have two... one for stack-by, and one for split-by. The toughest part would be if that negates the need for the "stacked" checkbox, then we would need to do a database migration to convert the "Dimensions" for existing charts to the relevant "Split By" or "Stack By" control.

[rusackas]

cc @jpchev - I should have replied inline above 🤦

[jpchev]

ok, thanks, I see how to implement it, I'm already experimenting and it seems it's not hard to get what I want

[geido]

Moving the discussion to the issue for PR tracking purposes #32496