Leaderboard Methodology

How contractors are ranked, who qualifies, and what every number on the leaderboard means.

Headline

Contractors are ranked by elevator-count-weighted average uptime across all attributed buildings in the last 90 days. A building with 10 elevators counts 10× as much as a building with 1. Contractors must have at least 3 attributed buildings with tracking data to appear.

Eligibility

To be ranked on the leaderboard, a contractor must have:

At least 3 attributed buildings with a confidence score of 0.70 or higher.
At least one of those buildings with tracked outage data in the 90-day window.

Contractors with fewer attributed buildings, or with no tracked outage data in any of their buildings, are not listed — neither ranked nor scored. No buildings, no ranking.

Formula

weighted_uptime
  = SUM(building_uptime_90d × elevator_count)
  / SUM(elevator_count)

Ranking: ORDER BY weighted_uptime DESC,
                  building_count DESC,
                  elevator_count DESC

Per-building uptime is the same figure shown on each building scorecard: downtime is weighted (confirmed outages count fully, unconfirmed outages count at 25%, disputed outages are excluded) and divided by the hours that building has actually been tracked in the window. The denominator self-normalizes — a building tracked for one day reports its uptime over that one day; a building tracked the full 90 days reports it over 90 days. Both are valid percentages of observed data.

Tiers

Featured (Top performer) — contractors in the top 10% of weighted uptime with at least 10 attributed buildings. Highlighted with a badge.
Ranked — contractors meeting the 3-building eligibility threshold with at least one building reporting tracked outage data. Shown in the main table.
Not listed — contractors below the 3-building minimum or with no tracked outage data on any attributed building. Counted in the page footer but not displayed.

Parent vs. Regional

By default the leaderboard rolls subsidiaries up into their OEM parent: the uptime record of every Otis regional office counts toward “Otis.” Toggle to Regional view to see individual offices and independent contractors side by side.

Trend indicator

The trend arrow compares the contractor’s current 90-day weighted uptime against the prior 90-day window (days 91–180 ago). ▲ means uptime improved by more than 0.5 percentage points, ▼ means it declined by more than 0.5 pp, – means flat or no prior data.

Where the data comes from

Attributions are sourced from a tiered mix of regulatory permits (NYC DOB, FL DBPR, TSSA Ontario, TX TDLR, CA DOSH, Cleveland Accela, Fairfax County, Washington DC), direct claims, OEM inference, and community reports. Each source has a confidence weight — only observations at 0.70 or above count toward leaderboard eligibility. See the global attributions methodology for the per-source breakdown.

Update cadence

Rankings are live — every page load recomputes them from the most recent outage and attribution data. Expect rankings to shift as new inspections are ingested, outages resolve, and buildings cross the 7-day tracking threshold.

Disputes

If you’re a contractor who believes an attribution is incorrect, or a building manager whose service provider is mislabeled, the ranking formula is intentionally published here so we can point to exactly what needs to change. Contact us with source documentation (permit number, contract excerpt, etc.) and we’ll reconcile the attribution.