Platform Health score calculation model

concept australia Updated Oct 7, 2026 3 min read instance-health-score-calculation.md
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Your Platform Health score is the foundation for understanding instance risk. The score reflects platform risk through a four-step, category-weighted calculation that combines findings into a single 0–100 health metric.

Each scoring category is evaluated independently, then combined into a single overall score using fixed category weights. A critical Security finding should not be weighted exactly the same as a cosmetic User Experience finding, and remediating a Performance issue should not alter your Upgradeability score. The priority order by category scoring capacity is:

  1. Security
  2. Performance
  3. Upgradeability
  4. Manageability
  5. User Experience
Step What happens Why it matters
1. Fixed reference Each check compares its own findings to a stable reference point established when the definition was authored, not to the largest finding count in that scan. Fixing one check doesn't distort the weight of another.
2. Category scoring Security, Performance, Manageability, Upgradeability, and User Experience are each scored independently, 0–100. You can see exactly which category needs attention and why.
3. Weighted roll-up Category scores combine into one overall Platform Health score, weighted by how much each category matters to your risk. Security counts more than a cosmetic issue.
4. Same scope for Full and Delta Full and delta scans count findings on the same instance-wide basis. See Full and delta scans for more information on scans. Your score means the same thing, regardless of scan type.

Formulas

Here are the four steps translated into the actual calculations.

Step

Formula

What it computes

  1. Magnitude

Magnitude = min(2, 1 + ln(1+F) ÷ ln(1+R))Note: Magnitude = 0 when F = 0, and is capped at 2 after F reaches R. This is the natural logarithm.

How widely a check fired, capped at 2× so one check can't dominate its category.

  1. Weighted penalty

Penalty = W × Magnitude

The check's own contribution to its category's burden.

  1. Category health

CategoryHealth = clamp(100 × (1 − ΣPenalty ÷ ΣCeiling), 0, 100)

A 0–100 health score for that category alone, unaffected by any other category.

  1. Overall score

Score = Σ (CategoryWeight × CategoryHealth)

Category scores combined into one Platform Health score, weighted by importance.
Where:
  • F: The number of records a check found.
  • R: The check's stable reference point. R is not set per definition. It is a fixed tier: 10 for checks that return one finding for an entire table, 20,000 for all others.
  • W: The check's own weight, based on its severity and impact.
  • Category Weight: The category's share of overall risk, shown in the following category weights table.
  • ΣPenalty: The sum of all weighted penalties in that category.
  • ΣCeiling: 2 × W for every active check in the category, whether or not it fired.

How categories are weighted

Category weighting reflects how much risk each area typically represents across the check library. These weights are applied only at the final roll-up step, so a change in one category's findings won't distort the calculated health of another category. See Scan Engine definitions for their definitions.

Category Weighting Description
Security ~40% The highest-consequence category, encompassing breach risk, compliance violations, and access-control vulnerabilities.
Performance ~22% Affects every user on the instance and compounds if left unaddressed.
Manageability ~19% The largest category by volume, impacting administration and supportability.
Upgradeability ~9% Smaller in volume but can block or delay ServiceNow release upgrades.
User Experience ~9% Important to adoption and satisfaction, but carries the lowest urgency overall.

Note: Publishing new definitions does not change the score on its own.

For more information, see the following:

Parent Topic:Scan Engine reference

Keywords Instance Health ScorePlatform Healthscore calculationcategory weightsScan Engine
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