---
sourceDocument: Brazil Impact
sourceDocumentLink: https://www.servicenow.com/docs/r/impact

 Release :

    - brazil

ft:locale :

    - en-US

ft:publication_title :

    - Brazil Impact

ft:clusterId :

    - ipact

bundleId :

    - ipact


---

# Health Score calculation

# Instance Health Score calculation model {#ariaid-title1}

Release version: Brazil  
Updated September 29, 2026  
![](https://www.servicenow.com/docs/portal-asset/ico-clock) 4 minutes to read
Summarize  
![AI sparkle icon](https://servicenow.com/docs/portal-asset/ai-sparkle-icon) Summarized using AI  
This content was generated using new OpenAI-powered functionality. Results are provided on an as is basis and are not guaranteed to be accurate or complete.  

## Summary of Instance Health Score calculation model

The Instance Health Score provides a comprehensive metric to assess your ServiceNow platform's risk by evaluating key health categories independently and combining them into a single score from 0 to 100.
This score helps you understand your instance's overall health, prioritize remediation efforts, and track risk trends consistently over time, regardless of scan type.
Show full answer Show less  

## Key Features

* **Four-step weighted calculation:** The score is derived through a fixed reference comparison, independent category scoring, weighted roll-up by category importance, and consistent scope for Full and Delta scans.
* **Category-based scoring:** Five categories are scored separately---Security, Performance, Manageability, Upgradeability, and User Experience---allowing clear identification of which areas need attention.
* **Fixed reference points:** Each check's findings are measured against a stable reference established when the check was defined, ensuring scores reflect true platform health without distortion from other checks or changes.
* **Weighted category roll-up:** Categories contribute to the overall score based on their risk impact, with Security weighted highest (\~40%) and User Experience lowest (\~9%), ensuring critical risks weigh appropriately.
* **Consistent comparison across scan types:** Both Full and Delta scans use the same instance-wide counting scope, so health scores remain comparable and trend lines reliable regardless of scan method.

## Key Outcomes

* You gain a reliable, stable health metric reflecting platform risk across important categories, enabling targeted remediation prioritization.
* The model prevents any single check from disproportionately skewing category or overall scores, maintaining balanced visibility into health issues.
* You can confidently compare health scores over time and across scan types, supporting continuous monitoring and improvement efforts.
* The familiar 0--100 scoring scale and category definitions remain unchanged, minimizing the learning curve and maintaining intuitive interpretation.
* Dashboards and user interactions with findings continue as before, ensuring operational familiarity while benefiting from improved scoring accuracy.  
The Instance Health Score reflects platform risk through a four-step category-weighted calculation. Each scoring category is evaluated independently, then combined into a single overall score using fixed category weights.
Your Platform Health Score is the foundation for understanding instance risk. 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 current model uses a four-step calculation model with distinct steps to combine findings into a single 0--100 health metric.
{#instance-health-score-calculation__table_calculation_steps__entry__3}

| Step | What happens | Why it matters |
|-|-|-|
| 1. Fixed reference | Each check compares its own findings to a stable reference point, not to the largest finding count in that scan. | Fixing one check can never 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, as it should. |
| 4. Same scope for Full and Delta | Full and Delta scans count findings on the same instance-wide basis. | Your score means the same thing no matter which scan produced it. |
[Table 1. Health Score calculation steps]

{#instance-health-score-calculation__table_calculation_steps}

## The calculation formulas {#instance-health-score-calculation__section_formula}

Here are the four steps translated into the actual calculations.
{#instance-health-score-calculation__table_formulas__entry__3}

| Step | Formula | What it computes |
|-|-|-|
| 1. Magnitude | `Magnitude = min(2, 1 + ln(1+F) ÷ ln(1+R))` | How widely a check fired, capped at 2× so one check can't dominate its category. |
| 2. Weighted penalty | `Penalty = W × Magnitude` | The check's own contribution to its category's burden. |
| 3. Category health | `CategoryHealth = clamp(100 × (1 − ΣPenalty ÷ ΣCeiling), 0, 100)` | A 0--100 health score for that category alone, unaffected by any other category. |
| 4. Overall score | `Score = Σ (CategoryWeight × CategoryHealth)` | Category scores combined into one Platform Health score, weighted by importance. |
[Table 2. Instance Health formulas]

{#instance-health-score-calculation__table_formulas}

Where:

* F: The number of records a check found.
* R: The check's stable reference point. Set when the definition was authored, this anchors the check's magnitude calculation.
* W: The check's own weight, based on its severity and impact.
* Category Weight: The category's share of overall risk, shown in the category weights table below.
* ΣPenalty: The sum of all weighted penalties in that category.
* ΣCeiling: The sum of all ceiling values for checks in that category.
{#instance-health-score-calculation__ul_formula_vars}

## How categories are weighted {#instance-health-score-calculation__section_category_weights}

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.

{#instance-health-score-calculation__table_category_weights__entry__3}

| Category | Proposed weight | Why |
|-|-|-|
| 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. |
[Table 3. Category weights and risk assessment]

{#instance-health-score-calculation__table_category_weights}

## Fixed reference points and stable measurement {#instance-health-score-calculation__section_fixed_reference}

Each check compares its findings to a fixed reference point established when the definition was authored. This reference point anchors the magnitude calculation so that:

* Fixing one finding can never distort the weight of another unrelated finding.
* A category's score is computed only from its own checks; changes in other categories do not affect it.
* The relationship between findings and the scoring metric remains consistent over time.

{#instance-health-score-calculation__ul_fixed_reference}

This contrasts with the previous model, which measured every finding against the largest count seen in that scan run. The new approach ensures your score reflects actual platform health, not relative noise.

## Full and delta scans are comparable {#instance-health-score-calculation__section_full_delta_comparability}

Both Full and Delta scans use the same instance-wide counting scope for every definition. This means a Full scan and a Delta scan against the same instance state produce comparable results, so your trend line holds up regardless of
which scan type you run. See [Full and delta scans](https://www.servicenow.com/docs/0uD14YiK3EqjCn1q5bOtqw "The full and delta instance scan feature with Impact Platform Health Scan Engine enables ServiceNow administrators and developers to initiate, monitor, and manage instance health.") for additional information on scans.

## What stays the same {#instance-health-score-calculation__section_what_stays_same}

* Your score still runs 0--100, with higher meaning healthier, so you do not need to relearn a new scale.
* Full and Delta scans remain directly comparable, so your trend line still holds up.
* You can still prioritize remediation by weighted burden; the highest-impact fixes still surface first.
* The five categories you already know are unchanged. See [Scan Engine definitions](https://www.servicenow.com/docs/HYGJFcSGcpcvjlOxv13Z2g "The Scan Engine uses a large set of definitions to correct coding and workflow findings in real-time and perform scans across your entire instance to detect existing findings.") for their definitions and role in the weighted model.
* The visual execution of Health Score dashboards and the way you interact with findings remain familiar.
{#instance-health-score-calculation__ul_unchanged}

## Related concepts {#instance-health-score-calculation__section_related_concepts}

For more information, see the following:

* [Scan Engine definitions](https://www.servicenow.com/docs/HYGJFcSGcpcvjlOxv13Z2g "The Scan Engine uses a large set of definitions to correct coding and workflow findings in real-time and perform scans across your entire instance to detect existing findings.") --- Category definitions and their weights
* [Scan Engine Executive dashboard](https://www.servicenow.com/docs/DrlyU406sw05i~uhE1b09Q "The Executive dashboard includes trend charts and the following overview modules.")
* [Scan Engine Platform Owner dashboard](https://www.servicenow.com/docs/eCWwptsLeyqcWPcAdvGS5A "The Platform Owner dashboard includes trend charts and the following overview modules.")
* [Scan Engine Team Lead dashboard](https://www.servicenow.com/docs/dit~837itDATrjGdSxRJ2A "The Team Lead dashboard includes trend charts and the following overview modules.")
{#instance-health-score-calculation__ul_related}