The Box Plot (box-and-whisker) component displays the statistical distribution of a numeric field across a category or group. It shows the median, interquartile range, and the spread of values, making outliers and distribution shape immediately visible. Common uses include activity duration distribution by discipline, resource cost spread per contractor, and risk score distribution by category.
Display modes
| Mode | Description |
|---|
| Box only | Shows box (IQR) and median line without individual data points. Cleanest for many categories. |
| Box + points | Shows the box and individual data points plotted beside it. Reveals the underlying distribution and point density. |
| Points only | Shows individual data points without the box. Use for small datasets where distribution shape is less important than individual values. |
Data binding
| Property | Description |
|---|
| Category field | Field used to group distributions into separate boxes (one box per unique value). |
| Value field | The numeric field whose distribution is visualised per category. |
| Series field | Optional field to split each category into multiple overlaid boxes per series. |
Whisker modes
Whiskers extend from the box (interquartile range) to show the outer spread of the data:
| Whisker mode | Description |
|---|
| Tukey (1.5 × IQR) | The standard box plot whisker. Extends to the furthest data point within 1.5 × the IQR from the box edges. Points beyond the whiskers are shown as outliers. |
| Max extent | Whiskers extend to the absolute minimum and maximum values. No outlier points are shown. |
| Percentile | Whiskers extend to configurable percentiles (e.g., 5th–95th, 10th–90th). Configure the lower and upper percentile values. |
| Std deviation | Whiskers extend N standard deviations from the mean. Configure N (typically 1.5 or 2). |
| Custom | Manually set the lower and upper whisker bound as fixed values or field references. |
Statistical markers
| Marker | Description |
|---|
| Median line | The horizontal line inside the box at the 50th percentile (always shown). |
| Mean marker | An X or diamond marker at the mean value (enable in Properties → Markers). |
| Outlier points | Individual dots for values beyond the whiskers (automatic in Tukey mode). |
| Notch | A narrowing of the box around the median to visualise confidence intervals for median comparison. |
Outlier highlighting
Configure outlier point appearance:
| Property | Description |
|---|
| Outlier color | Distinct color for outlier points. |
| Outlier size | Point radius in pixels. |
| Outlier label | Optional field to label identified outlier points (e.g., Activity ID). |
| Highlight threshold | Points beyond N × IQR are highlighted in a warning color. |
Precomputed data mode
When your data source already contains the pre-calculated statistical values (e.g., from a SQL view), enable Precomputed mode and bind:
| Bind | Field description |
|---|
| Min | Minimum value (or lower whisker) |
| Q1 | 25th percentile |
| Median | 50th percentile |
| Q3 | 75th percentile |
| Max | Maximum value (or upper whisker) |
| Mean | Optional mean for the mean marker |
In precomputed mode, the component renders directly from these fields without re-calculating statistics from row-level data.
Appearance options
| Option | Description |
|---|
| Box fill color | Fill color of the IQR box. Can be per-category or a single color. |
| Box border color | Border color of the box. |
| Whisker line style | Solid, dashed, or dotted. |
| Category axis label angle | Rotate labels for long category names. |
| Orientation | Vertical (default) or horizontal. |
Good practice
- Use Tukey mode (default) for most project control uses.
- Add the mean marker when comparing distributions where mean vs. median difference is meaningful.
- For small datasets (< 10 points per category), use Box + Points mode to show the underlying data.
- Label outlier points when the identity of the outlier is significant (e.g., which activity is the outlier).