Pbi Report Design

Power BI Report Design

Use pbir for every report mutation. The pbir-format skill is read-only schema context. If the CLI is unavailable or lacks an operation, stop and report the gap.

Best practices and guidelines for Power BI report design. Follow these guidelines strictly to avoid generic, poorly formatted reports ("Power BI Slop").

Be innovative, pushing boundaries while adhering to data visualization rules and guidelines. Work within Power BI's constraints, aiming for simplicity and effectiveness over aesthetics and decoration. Focus reports, pages, and visuals on answering specific questions and minimizing cognitive load -- not on looking "pretty and impressive".

When a user request contradicts these guidelines, push back and explain better alternatives. The goal is to inform the user of options that lead to improved outcomes.

Design identity (commit before layout)

Before any layout work, lock the report's identity so every later choice has something to cite:

1. Pick one tone ... a committed ink budget (restrained, corporate, editorial, or technical) that fixes accent count, saturation, gridline weight, and how forward annotation gets
2. Pick one signature (two at most) ... a single recurring element (header band, single-accent-hue rule, fixed nav rail, KPI silhouette, callout style, target-line convention) repeated identically on every page, so the report reads as one artifact
3. Route each page to one shape by the question it answers (summary, monitoring, exploration, comparison, narrative)

Recording tone and signature once is what turns "use muted colors" into a propagating decision. See references/design-identity.md for the tone budgets and signature catalog, and references/page-shapes.md for routing each page to a shape. Serialize the identity into the theme via the modifying-theme-json skill, not into per-visual overrides.

Core rules

1. 3-30-300 Rule: The most important and least detailed information should be in the top-left (KPIs, cards, etc.) while the least important and most detailed information should be in the bottom-right
2. Titles: All report pages should have a title using a textBox visualType or a title in a background image added to the report page canvas
3. Visual positioning, alignment, and spacing: All visuals must have equal spacing between them and equal spacing between the edge of the page (the margin). If visuals are unaligned or this spacing is unequal, fix it to ensure alignment and equal spacing
4. Themes: Reports should use a theme that differs from the default Power BI themes; a suggested theme is the sqlbi theme (see the modifying-theme-json skill for applying templates). Themes are preferred because they provide a set of default styles for all charts that can adhere to good design practices and brand or style guidelines
5. Semantic Models: Reports in Power BI are complex. They are dependant on an underlying semantic model (either in the .SemanticModel folder, called a "thick report" or a published model in Power BI/Fabric, called a "thin report"). Much of the functionality from a Power BI report comes from its semantic model design or DAX code
6. Report extensions, or thin report measures: It is possible to create calculation logic in Power BI report, called "thin report measures" or "visual calculations". These should be used sparingly and only for "report-specific" scenarios
7. Visual fields: All data visuals should have field bindings, and all field bindings should be for fields that actually exist in the model; there is no reason for visuals to exist that have no fields bound
8. Chart selection: Make smart choices about what visuals to use for each scenario. Visual vocabulary is essential for this skill.
9. Use of color: Color and formatting decisions must cite the locked identity (the chosen tone and signature), not be picked per visual. Colors come from the theme (themedataColor) rather than inline hex, so the identity propagates and re-themes cleanly. Colors should be muted and soft; colors that implicitly encode meaning (like red=bad, green=good) should be avoided unless using them for that encoding. Consider colorblindness and use accessible palettes (blues instead of greens with reds, for instance).
10. Pre-attentive attributes: Styles and colors should be used to steer and direct attention, and not to decorate charts. Formatting of visuals should be intentional and not purely aesthetic. Styles should where possible be stored in the theme and not in bespoke visual configuration.
11. Fonts: Prefer Segoe UI and Segoe UI Semibold. Do not use custom fonts, since they aren't guaranteed to render on user computers. Evaluate whether fonts are sufficiently large to be readable given the visual and page size.
12. Page intent: Route each page to exactly one shape by the question it answers (see references/page-shapes.md). A page trying to answer two questions is two pages.

The insight test (run before building a chart)

A chart is cheap to reject on the spec and expensive to reject on the canvas. Run these five tests against the proposed chart, before any pbir add visual. They are rejection tests, not a generation quota: a chart that passes all five gets built as specced, and no extra candidates are generated to compete with it.

1. The title states the insight, not the shape. "Additions peaked in 2019 and have halved since" is a title; "Titles by year" is a caption for an axis that already says so.
2. Every mark carries a measure. A mark placed for texture, balance, or to fill a panel is decoration. Cut it.
3. Every figure has a denominator, and one denominator. A percentage whose base is unstated is unreadable; a panel that mixes two bases in one frame is wrong, not merely unclear.
4. No panel restates its neighbour. If a tooltip, card, or sub-chart shows only what the visual it sits beside already prints, it is a duplicate. This is the most common failure and the easiest to see on the spec.
5. The title points the same direction as its own measure. A title claiming growth over a measure that falls is a defect that survives every schema validation, because nothing in the JSON knows what the words mean.

When a chart fails: simplify it to a single comparison, or cut it. Do not repair it in place through successive renders; that is how one bad panel consumes an evening. Record which you chose, and why, in the plan's fog list (see the pbi-plan skill) so the decision is not rediscovered next session.

The test is deliberately blind to how good the chart could be. It discriminates on whether the chart says something, which a render cannot tell you any better than the spec can.

Page Layout Guidelines

Check Page Size Before Modifying

Always query the actual page dimensions before adding or repositioning visuals. Do not assume a page is 1280x720 or 1920x1080 -- templates and existing reports vary. The object model validates that visuals fit within page bounds, so setting position or size without knowing the page dimensions will cause errors. Check the page's page.json file for width and height properties, or use the object model (page.width, page.height) to confirm dimensions first. When resizing visuals via the object model, set width/height before x/y to avoid intermediate states that exceed bounds.

Standard Page Size

• Width: 1280px (default)
• Height: 720px (16:9 aspect ratio)
• Alternative: 1920x1080 for high-resolution displays

Visual Spacing

• Minimum gap between visuals: 16px
• Edge margins: 24-32px from page edges
• Consistent alignment: Use grid-based positioning
• Equal spacing is mandatory: Every gap between adjacent visuals (horizontal and vertical) must be the same value. Every margin from the page edge must be the same value. Calculate positions arithmetically from (margin, gap, page_width, page_height) to guarantee alignment. If visuals are misaligned or gaps are unequal, fix immediately -- this is one of the most visible quality signals in a report.

Detail Gradient

Arrange content following the "detail gradient":

+------------------+------------------+
|   KPIs/Cards     |   KPIs/Cards     |  <- Top: High-level, important
|   (Summary)      |   (Summary)      |
+------------------+------------------+
|                                     |
|   Charts/Trends                     |  <- Middle: Context, trends
|   (Analysis)                        |
|                                     |
+------------------+------------------+
|                                     |
|   Tables/Details                    |  <- Bottom: Detailed data
|   (Drill-down)                      |
|                                     |
+------------------+------------------+

Visual Count Guidelines

• Maximum visuals per page: 12-15 (performance impact)
• Maximum KPIs/Cards: 4-6 at top
• Maximum slicers: 3 per page (use filter pane instead)

Page Titles

Every page should have a title. Create it through pbir:

pbir add title "Report.Report/Page.Page" "Page Title" --width 500

Title positioning:

• Top-left corner, inside the page margin
• Enough height for the chosen font without clipping
• Width: 400-600px (or page width minus margins)

Theme Guidelines

Always Check Theme First

Before modifying visual formatting:

1. Check theme wildcards: visualStyles["*"]["*"]
2. Check visual-type overrides: visualStyles.lineChart["*"]
3. Only override in visual.json if truly one-off

When to Modify Theme vs Visual

• All visuals of a type need change -> theme
• Establishing design standards -> theme
• Single visual exception to a theme rule -> visual
• Content-specific highlight (one callout, one reference line) -> visual

Theme Color Usage

Prefer theme colors over hex codes:

// Good - uses theme color
"expr": {"ThemeDataColor": {"ColorId": 1, "Percent": 0}}

// Avoid in visuals - use only in extension measures
"expr": {"Literal": {"Value": "'#118DFF'"}}

Semantic colors (return from extension measures):

• "good" - Positive values (green)
• "bad" - Negative values (red)
• "neutral" - Neutral/unchanged (gray/yellow)
• "minColor" - Gradient minimum
• "maxColor" - Gradient maximum

Accessibility (WCAG 2.1)

Alt Text

All visuals should include descriptive alt text:

"visualContainerObjects": {
  "general": [{
    "properties": {
      "altText": {
        "expr": {"Literal": {"Value": "'Line chart showing monthly sales trend from January to December 2024'"}}
      }
    }
  }]
}

Color Contrast

• Text on background: minimum 4.5:1 contrast ratio
• Large text (18pt+): minimum 3:1 contrast ratio
• Don't rely solely on color to convey meaning

Font Sizes

• Minimum readable: 12pt
• Recommended for charts: 14pt
• Titles: 16-24pt
• KPI values: 24-48pt

Shadows and Motion

• Minimize drop shadows (vestibular issues)
• Avoid animations where possible
• Use dropShadow.show: false in theme wildcards

Visual Best Practices

Cards and KPIs

A bare number lacks meaning. Every KPI must answer "Is this good or bad?" (target + gap) and "Is it getting better or worse?" (trend). Key rules:

• Position at top or left of page, maximum 5 per page
• Prefer kpi visual type over card when a target exists -- it has built-in indicator, goal, and trend line data roles
• Always include a target and gap (absolute + percentage). If no target measure exists, discuss with the user: propose adding a prior-year measure to the semantic model (use Tabular Editor CLI or the tmdl skill), or creating an extension measure as a fallback. Common targets: prior year (CALCULATE([Measure], DATEADD('Date'[Date], -1, YEAR))), budget, or rolling average
• If no clear target exists, ask the user -- do not leave KPIs bare. Discuss whether prior period, budget, or a custom threshold makes sense
• Apply conditional formatting to the gap, not the primary value
• Pair color with a secondary cue (arrow/icon) for accessibility
• Round aggressively at summary level ("518M" not "517,893,412")
• Choose actionable metrics that drive decisions over vanity metrics (apply the "20% change test": if this number changed 20%, should someone act differently?)
• Hide redundant auto-generated subtitles
• Use SVG extension measures for inline icons (see the svg-visuals skill in the custom-visuals plugin)

For complete guidance on KPI design, targets, trends, formatting hierarchy, icon implementation, accessible palettes, and anti-patterns, consult references/cards-and-kpis.md.

Charts

• Sort by value descending (unless time-based)
• Minimize gridlines and axes clutter
• Use muted colors for non-essential elements
• Highlight key data points sparingly

For chart-type selection (encoding hierarchy, Cleveland-McGill ranking), data-label discipline, and small-multiples guidance, consult references/chart-selection.md.

Refuse common LLM defaults. Gauge-as-KPI, monochrome categorical bars, missing sort, card walls, raw field names as titles, inline hex, off-grid drift, dual y-axis, 3D, and oversized pies are plausible-looking attractors that defeat the reader. When a request reaches for one, push back with the better option; see references/anti-patterns.md.

Tables and Matrices

Tables require deliberate design -- "easy to create" differs from "easy to read." Key rules:

• Position at bottom for detail drill-down (3-30-300 rule)
• Decision-making first: define the question, audience, and action before building
• Use matrix over tableEx when 2+ categorical columns form a hierarchy (Key Account > Account > Product)
• Subtract, don't add: remove gridlines and heavy banding; let whitespace separate rows
• Sort by the most important measure (often variance), not alphabetically
• Apply data bars to the primary measure column for magnitude scanning
• Apply color scales to variance columns only -- formatting everything means formatting nothing
• Add sparklines where temporal context ("improving or declining?") matters
• Show full precision (no display units) -- tables are where readers go for detail
• Indent hierarchy row labels with U+00A0; leading ASCII spaces are trimmed on render, and filters on the label then stop matching

For complete guidance on table vs matrix selection, formatting philosophy, conditional formatting techniques, sparklines, hierarchy design, row-label indentation, and anti-patterns, consult references/tables-and-matrices.md.

Slicers

• Maximum 3 per page
• Position consistently (top or left)
• Use filter pane for additional filters
• Consider sync slicers across pages

Filter Pane

The filter pane has its own information architecture beyond color and chrome. Key decisions: lock vs hide per filter card, how to name cards without renaming model fields, and report-level settings (Apply button, search, allow-change-filter-type). See references/filter-pane.md.

Mobile

Power BI does not reflow a desktop page for portrait; the phone layout is a hand-picked subset re-placed on a narrow grid. Nothing renders on a phone until explicitly opted in with a mobile.json. See references/mobile.md for the subset-selection model and file mechanics.

Report Evaluation Criteria

When asked to evaluate or audit a report, focus on objective criteria. Subjective evaluation is difficult for AI -- the report cannot be "seen" directly, and there is no intuitive sense of aesthetics, cognitive load, or effectiveness. Emphasize this limitation to users.

Objective Checklist

1. Page count: More than 5-8 pages is typically excessive
2. Visuals per page: Count is a proxy; query cost per visual is the driver (see references/layout-guidelines.md performance section). Textboxes, images, shapes, and buttons do not emit queries.
3. Theme usage: Reports should use a custom theme for consistent formatting
4. Layout consistency:
   • Equal spacing between visuals?
   • Page has a title?
   • Follows detail gradient (important top-left, detailed bottom-right)?
   • Cards/KPIs at top or left, fewer than 4-6?
   • Fewer than 3 slicers (use filter pane instead)?
   • Helpful elements (refresh date, links, context)?
5. Color effectiveness:
   • Conditional formatting used sparingly (not causing overload)?
   • Colors muted and passive (not loud and bright)?
   • Negative-sentiment colors (red, orange) only for negative values?
6. Information:ink ratio: Non-essential elements reduced (lighter gridlines, disabled unnecessary axes/labels)?
7. Readability: Font sizes sufficient for all elements?
8. Accessibility: Minimal shadows to avoid vestibular issues?
9. Font consistency: Limited font sizes, simple readable fonts that work on all devices?
10. Sorting: Visuals sorted descending unless there's a reason otherwise (time-based, etc.)?

Evaluation Output

When evaluating, provide:

• Issues found with specific locations
• Severity (critical, warning, suggestion)
• Recommended fixes with commands or patterns

The design gate

Before declaring a design done, run the closing gate in references/quality-gate.md. It is not the planning-stage checklist that runs before the build; it runs against the finished artifact and decides whether it ships. It verifies the identity propagated, every page has one intent, spacing and margins are equal and on-grid, callouts are backed by model evidence, and accessibility is met. Because an agent cannot see the canvas, pair the gate with the screenshot-review loop in the pbir-cli skill: render the pages, look, and confirm what the JSON inferred.

Implementing an approved design

Once a design is agreed, the failure mode changes. It stops being "is this good" and becomes "did we build the thing we agreed, without breaking what was already there". The rules for that phase are in references/implementing-a-design.md: apply the delta only and never replace existing chrome, check what else consumes a shared object before editing it, validate and then actually look before claiming done, defer cleanup rather than fighting a file lock, and write a reverse brief from the report's current state when another design round is needed. They are technique-agnostic and apply to any design source.

Common Design Issues

Issue: Cognitive Overload

Symptoms: Too many colors, visuals, or data points

Fix:

• Reduce visual count
• Use muted color palette
• Apply detail gradient
• Hide non-essential elements

Issue: Inconsistent Spacing

Symptoms: Uneven gaps, misaligned visuals

Fix:

• Use grid-based positioning
• Standardize visual sizes
• Apply consistent margins

Issue: Poor Readability

Symptoms: Small fonts, low contrast

Fix:

• Increase font sizes (minimum 12pt)
• Check color contrast ratios
• Use appropriate font weights

References

• references/design-identity.md -- Commit-first identity: tone budgets (restrained/corporate/editorial/technical), the signature catalog, and serializing identity into the theme
• references/page-shapes.md -- Routing each page to one shape by intent (summary/monitoring/exploration/comparison/narrative): what belongs, what stays off, layout lean
• references/anti-patterns.md -- Cross-cutting defaults to refuse (gauge-as-KPI, monochrome bars, missing sort, card walls, raw titles, inline hex, off-grid, dual-axis, 3D, oversized pie) with the repair
• references/quality-gate.md -- The design gate: closing checks (identity propagated, one intent per page, equal spacing, evidence-backed callouts, accessibility) in issue/location/severity/fix form
• references/cards-and-kpis.md -- KPI card design: targets, gaps, trends, formatting hierarchy, icons, accessible palettes, anti-patterns, review checklist
• references/tables-and-matrices.md -- Table and matrix design: decision-making framework, subtract-don't-add philosophy, conditional formatting, sorting, sparklines, matrix hierarchies, row-label indentation (U+00A0), anti-patterns
• references/layout-guidelines.md -- Canvas dimensions, spacing tiers (intra-group/inter-group/margin), alignment rules, performance cost model
• references/visual-colors.md -- Color principles, CF basis decision (gradient vs rules vs field-value vs icons), semantic tokens, accessibility
• references/page-titles.md -- Title implementation, accessible title wording, hidden-title/alt-text rule
• references/chart-selection.md -- Encoding hierarchy (Cleveland-McGill ranking), chart type routing, data-label discipline, small multiples
• references/tooltips-and-annotations.md -- Report-page tooltip design, when not to use one, annotation primitives for guided analytics
• references/filter-pane.md -- Lock vs hide, card naming, card order, Applied/Available styling, report-level settings
• references/mobile.md -- Phone layout as a curated subset, mobile.json mechanics, what to include/exclude
• references/custom-visuals.md -- Build-vs-buy ranking, AppSource/org-store tradeoffs, licensing gaps
• references/implementing-a-design.md -- Turning an approved design into a report: delta-only application, preserving existing chrome, shared-object scope discipline, validate-then-look verification, deferred cleanup, and the reverse design brief with its template

Related Skills

Report Structure and Format

• pbir-format (pbip plugin) -- PBIR JSON format reference for visual.json, page.json, report.json structure
• pbip (pbip plugin) -- PBIP project structure, table/measure renames, project forking

Custom Visuals

Reports often need visuals beyond what Power BI provides natively. Always consider in-repo code paths before reaching for a packaged third-party visual. See references/custom-visuals.md for the build-vs-buy decision and AppSource/org-store tradeoffs.

Skill routing for in-repo code visuals (all in the custom-visuals plugin; add with claude plugin install custom-visuals@power-bi-agentic-dev):

• deneb-visuals -- Vega/Vega-Lite declarative visuals; preferred for advanced custom interactive charts (cross-filtering, tooltips, hover)
• svg-visuals -- SVG via DAX measures; preferred for inline table/matrix/card graphics with no row cap issues
• python-visuals -- matplotlib/seaborn scripts (static PNG); for statistical visualizations that must compute at render time
• r-visuals -- ggplot2 scripts (static PNG); where R's statistical ecosystem has no Python peer (forecast, pheatmap, corrplot)

Semantic Model

Reports are highly dependent on the underlying semantic model for their functionality. Most report capabilities -- measures, calculated columns, relationships, hierarchies, row-level security -- are defined in the semantic model, not the report. When designing or modifying reports, you will frequently need to understand or modify the model. Key skills:

• tmdl (pbip plugin) -- Direct TMDL file editing for measures, columns, relationships
• te-docs (tabular-editor plugin) -- Tabular Editor CLI for model operations
• c-sharp-scripting (tabular-editor plugin) -- C# scripts for bulk model changes
• bpa-rules (tabular-editor plugin) -- Best Practice Analyzer rules for model quality
• connect-pbid (pbi-desktop plugin) -- Connect to Power BI Desktop's local Analysis Services instance for live model queries and modifications