2.4Maintaining the Matrix Over Time

Device matrices are not static. Review and update quarterly:

def quarterly_matrix_review():
    """Review and update the device matrix quarterly."""
    current_matrix = load_current_matrix()
    new_analytics = analytics.get_device_breakdown(days=90)

    changes = []

    for device in new_analytics:
        # New device that crossed the Tier 2 threshold
        if device["share"] >= 0.02 and device["model"] not in current_matrix:
            changes.append({
                "action": "ADD",
                "device": device["model"],
                "share": device["share"],
                "reason": f"New device with {device['share']*100:.1f}% share"
            })

    for device in current_matrix:
        # Existing device that dropped below relevance threshold
        current_share = get_current_share(device, new_analytics)
        if current_share < 0.01:
            changes.append({
                "action": "REMOVE",
                "device": device["model"],
                "share": current_share,
                "reason": f"Share dropped to {current_share*100:.1f}%"
            })

    return changes

What Triggers an Immediate Matrix Update

Trigger	Action
New OS major version released	Add latest OS to Tier 1 devices
New flagship device launched	Add if it enters top 10 within 2 weeks
Device share drops below 1%	Move to Tier 3 or remove
New form factor (foldable, etc.)	Add to edge case testing
New market expansion (new country)	Pull analytics for that market, update matrix
Bug report from specific device	Temporarily promote to Tier 1 for investigation