Main Decomposition Chart
Chart Overview
The main decomposition chart is the centerpiece of your MMM analysis, visually showing how different marketing and non-marketing factors contribute to your KPI over time.
Purpose: Visualize group-level contributions over time using stacked bars and show model fit with actual vs. predicted lines.
Two-Chart Layout
Chart 1: Actual vs Predicted (Line Chart)
Top chart shows model fit quality:
Black Solid Line - Actual KPI:
Your real historical data
Ground truth
What actually happened
Red Dashed Line - Predicted KPI:
Model's prediction
Sum of all contributions
What the model says should happen
Gap Between Lines:
Small gaps: Good model fit
Large gaps: Model missing something
Systematic patterns: Specification issues
Chart 2: Contribution Breakdown (Stacked Bar Chart)
Bottom chart shows the decomposition:
Stacked Bars:
One bar per time period
Height = Predicted KPI value
Each segment = one group's contribution
Color Coding:
Each group has unique color
Consistent across all time periods
Legend shows group-color mapping
Stacking Order:
Base at bottom (usually gray)
Other groups stack on top
Negative contributions below zero
Reading the Stacked Bar Chart
Bar Height and Composition
Total Bar Height:
Equals predicted KPI value for that period
Should approximately match actual (black line)
Shows total explained value
Segment Heights:
Each colored segment = one group's contribution
Taller segments = larger contribution
Height varies over time based on activity
Example Interpretation:
Week 1 Bar (Height: $100,000):
├── Base: $40,000 (40%)
├── Media: $35,000 (35%)
├── Price: -$5,000 (-5%)
├── Promotions: $20,000 (20%)
└── Seasonality: $10,000 (10%)Color Segments
Base (Usually Gray):
Foundation/baseline
Constant term + baseline variables
Steady across periods
Represents organic demand
Marketing Groups (Blues, Teals):
Paid media channels
Variable over time
Spikes during campaigns
Incremental impact
Price (Red):
Can be positive or negative
Price decreases → positive (boost sales)
Price increases → negative (reduce sales)
Trade-off visible
Promotions (Orange):
Temporary spikes
Promotional periods visible
Event-driven contributions
Clear lift patterns
Seasonality (Green):
Regular patterns
Cyclical contributions
Predictable variation
Annual rhythms
Identifying Patterns
Campaign Spikes:
Marketing segments grow during campaigns
Align bars with known campaign periods
Measure incremental lift
Seasonal Cycles:
Regular up-and-down patterns
Quarterly or monthly rhythms
Align with business calendar
Baseline Trends:
Gradual changes in Base height
Growing or declining baseline
Long-term trajectory
Promotional Events:
Sharp spikes in promotion segment
Align with known sale events
Black Friday, holiday periods
Price Changes:
Step changes in price segment
Positive = price cuts boost sales
Negative = price increases reduce sales
Chart Elements and Controls
X-Axis (Time)
Format: Date labels (e.g., "Jan 2024", "Week 1")
Features:
Chronological order
Adjusts to data frequency (weekly, monthly)
Zoomable and pannable
Reading:
Left to right = past to recent
Identify specific periods
Compare across time
Y-Axis (KPI Value)
Format: KPI units (dollars, units, etc.)
Features:
Shows contribution magnitude
Starts at zero (or goes negative)
Auto-scales to data
Reading:
Higher = more contribution
Below zero = negative impact
Absolute values matter
Legend
Location: Below or beside chart
Elements:
Group name
Color swatch
Clickable for interaction
Interaction:
Click to hide/show groups
Isolate specific contributions
Compare subsets
Use Cases:
Hide Base to see only marketing
Show only Media to focus
Compare different scenarios
Toolbar (Top Right)
Available Tools:
🔍 Zoom: Enter zoom mode ➕ Zoom In: Magnify view ➖ Zoom Out: Reduce magnification ✋ Pan: Move view across time 🔄 Reset: Return to original view
Usage:
Access via icons
Hover for tooltips
Click to activate
Interactive Features
Zoom Functionality
Mouse Wheel Zoom:
Hover over chart
Scroll wheel to zoom in/out
Maintains aspect ratio
Focuses on mouse position
Selection Zoom:
Click and drag to select area
Releases to zoom to selection
Detailed view of period
Precise control
Button Zoom:
Click Zoom In/Out buttons
Step-wise magnification
Centered on current view
Controlled increments
Pan Navigation
Click and Drag:
Click on chart
Hold and drag left/right
Navigate across time
Explore different periods
Use Cases:
Move through long time series
After zooming, navigate to different periods
Compare different years
Reset View
When to Use:
Lost in zoomed view
Want to see full picture
Start fresh exploration
How:
Click Reset button
Returns to original zoom level
Shows all data
Hover Tooltips
On Stacked Bars:
Shows:
Date/time period
Group name
Contribution value
Percentage of total (if configured)
Example:
Date: March 15, 2024
Group: Media
Contribution: $45,230
Percentage: 35% of totalOn Line Chart:
Shows:
Date
Actual value
Predicted value
Difference (gap)
Analyzing Contributions
Absolute vs. Relative Contributions
Absolute (Bar Height):
Dollar amount or KPI units
Direct impact measure
Useful for ROI calculation
Relative (Percentage):
Proportion of total
Useful for comparing across periods
Shows mix changes
Both Matter:
Absolute for business value
Relative for strategic shifts
Comparing Time Periods
Week-over-Week:
How did contributions change?
Campaign starts/stops visible
Tactical insights
Month-over-Month:
Smooths weekly noise
Campaign-level patterns
Strategic trends
Year-over-Year:
Long-term changes
Growth patterns
Strategic evolution
Identifying Outliers
Unusually Large Contributions:
Special events
Data quality issues?
One-time occurrences
Investigate:
Check actual data for that period
Verify model input values
Confirm business context
Unusually Small Contributions:
Campaign pauses
Budget cuts
Off-season periods
Common Chart Patterns
Pattern 1: Steady Base with Variable Marketing
Appearance:
Large consistent gray base
Variable colored marketing segments on top
Marketing creates peaks
Interpretation:
Strong organic baseline
Marketing drives incremental growth
Clear campaign effectiveness
Business Implications:
Marketing is working
Incremental ROI calculable
Base protects from market downturns
Pattern 2: Growing Baseline
Appearance:
Base segment increasing over time
Upward trend in total bar height
Marketing contributions also grow
Interpretation:
Business is growing organically
Compound effects building
Positive momentum
Business Implications:
Strong market position
Word-of-mouth/brand building working
Marketing amplifies growth
Pattern 3: Seasonal Cycles
Appearance:
Regular up-and-down patterns
Seasonality segment varies predictably
Annual rhythms clear
Interpretation:
Strong seasonal business
Predictable demand cycles
Marketing timing matters
Business Implications:
Plan campaigns around seasons
Budget allocation by quarter
Inventory planning insights
Pattern 4: Campaign-Driven Spikes
Appearance:
Large temporary increases in marketing segments
Aligned with known campaign periods
Clear before-during-after pattern
Interpretation:
Campaigns create significant lift
Measurable impact
Timing is critical
Business Implications:
Campaigns are effective
Can calculate campaign ROI
Optimize frequency and timing
Pattern 5: Price Sensitivity
Appearance:
Large price segment (positive or negative)
Changes correlate with pricing actions
Clear trade-offs visible
Interpretation:
Price elastic market
Pricing strategy matters
Revenue vs. volume trade-off
Business Implications:
Pricing power assessment
Promotion vs. everyday pricing
Margin optimization opportunities
Tips for Effective Analysis
Start with the Big Picture:
View full time series first
Identify major patterns
Note anomalies
Then Zoom for Details:
Focus on specific campaigns
Examine transitions
Investigate outliers
Compare Across Periods:
Similar time periods year-over-year
Campaign vs. non-campaign periods
Growth phases
Use Legend Strategically:
Hide Base to see marketing clearly
Show only controllable factors
Isolate specific groups
Cross-Reference with Actual:
Check model fit constantly
Large gaps = investigate
Good fit = trust decomposition
Document Insights:
Screenshot key patterns
Note business explanations
Build narrative
Troubleshooting Visual Issues
Bars Don't Match Predicted Line:
Should be impossible (calculation error)
Refresh and re-run
Check console for errors
Colors Are Unclear:
Too many similar shades
Reassign colors in Contribution Groups
Use more distinct colors
Chart Is Cluttered:
Too many groups
Consolidate small groups
Use drill-down instead
Can't See Small Contributions:
Zoom in on specific periods
Hide large Base group
Use variable-level drill-down
Negative Values Confusing:
Normal for price increases
Represents KPI reduction
Business context clarifies
Best Practices
Regular Review:
Update decomposition weekly/monthly
Track changes over time
Build historical understanding
Multiple Views:
Zoom levels for different insights
Hide/show groups for focus
Time period comparisons
Combine with Other Analysis:
Cross-reference with diagnostics
Check against business events
Validate with stakeholders
Tell the Story:
Use charts to build narrative
Explain peaks and valleys
Connect to business strategy
Next Steps
After analyzing the main chart:
Use Group Decomposition to drill into specific groups
Calculate Channel ROI
Identify Seasonal Patterns
Export charts for presentations
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