Health Score and Experience Index both measure how much of a user's active time was affected by issues. This article uses one worked example for each score and explains why the results can differ even when they describe the same hour of user activity.
How the Two Scores Differ
Health Score uses fixed health categories such as CPU, memory, disk, latency, startup, and faults. It measures how many active minutes were affected by one or more of those categories. When more than one category is active in the same minute, Health Score splits that minute's weight evenly across the active categories:
Category impact cost = 1 / Number of active categories
Experience Index uses a curated set of sensors. Each sensor can contribute up to 5 eligible impact minutes in a 5-minute bucket. If the eligible impact across all triggered sensors exceeds 5 minutes, SysTrack allocates the 5 minutes proportionally among those sensors:
Sensor impact cost = Sensor eligible impact / Total eligible impact × 5
The two scores also organize time differently:
Health Score rolls impact into 10-minute active-time buckets and counts each affected minute once, even if more than one health category was active during that minute.
Experience Index uses 5-minute buckets and counts impact minutes for triggered sensors during active time. For the key concepts, see Understanding the Experience Index.
Health Score Example
This example uses 60 minutes of active time.
10-Minute Bucket | What Happened | Total Impacted Minutes |
|---|---|---|
08:00-08:10 | Startup affected 1 active minute | 1 |
08:10-08:20 | CPU affected 1 active minute and a fault affected 1 non-overlapping active minute | 2 |
08:20-08:30 | Latency affected 1 active minute and CPU affected 2 active minutes, with 1 minute of overlap | 2 |
08:30-08:40 | Latency affected 8 active minutes and CPU affected 7 active minutes, with 5 minutes of overlap | 10 |
08:40-08:50 | No impact | 0 |
08:50-09:00 | No impact | 0 |
Explanation:
08:10-08:20 bucket: non-overlapping minutes add, so 1 + 1 = 2.
08:20-08:30 bucket: the overlapping minute splits evenly between Latency and CPU (0.5 each). Latency's total cost for the bucket is 0.5, and CPU's is 1 (non-overlapping minute) + 0.5 (overlapping minute) = 1.5. Costs sum to 2, matching the bucket's impacted minutes.
08:30-08:40 bucket: with 5 minutes of overlap for 2 categories, the bucket has 10 impacted minutes. Latency cost: 3+(5×0.5)=5.5 minutes. CPU cost: 2+(5×0.5)=4.5 minutes.
Total impacted time is 15 minutes.
Health Score = (1 - 15 / 60) × 100 = 75%
This example shows three Health Score rules:
Different affected minutes add together.
Overlapping affected minutes count once.
A 10-minute bucket cannot contribute more than 10 impacted minutes.
Experience Index Example
This example uses the same 60 minutes of active time.
Sensor impact minutes for the example:
Extended High CPU Use: 2
Low WiFi Signal Strength: 1
High Destination Latency: 2
Critical Application Hang: 5
Assume the following Experience Index sensors triggered during the hour:
5-Minute Bucket | What Happened | Impact Cost (Minutes) |
|---|---|---|
08:00-08:05 | Extended High CPU Use triggered | 2 |
08:10-08:15 | Extended High CPU Use and Low WiFi Signal Strength triggered | 3 |
08:25-08:30 | Low WiFi Signal Strength triggered multiple times | 1 |
08:30-08:35 | High Destination Latency (2 impact minutes) and Critical Application Hang triggered (5 impact minutes) | 5 |
Explanation:
08:10-08:15 bucket: 2 + 1 = 3 impact minutes.
08:25-08:30 bucket: repeated triggers of the same sensor still contribute only 1 impact minute for the bucket.
08:30-08:35 bucket: High Destination Latency contributes 2 eligible impact minutes and Critical Application Hang contributes 5. The total is 7 minutes, so SysTrack allocates the 5 minutes proportionally: High Destination Latency has an impact cost of 2/7×5=1.43 minutes, and Critical Application Hang has an impact cost of 5/7×5=3.57 minutes.
Total Experience Index impact is 11 minutes.
Experience Index = (1 - 11 / 60) × 100 ≈ 82%
This example shows how Experience Index differs from Health Score:
Data is evaluated in 5-minute buckets instead of 10-minute periods.
If a sensor triggers multiple times in the same bucket, it contributes its impact only once.
If the eligible impact from triggered sensors exceeds 5 minutes, SysTrack allocates the 5 minutes proportionally among the sensors.
What to Expect When Comparing the Scores
In these examples, the same 60 active minutes produce two different results. This difference is expected. Health Score uses fixed health categories and counts overlapping categories within the same affected minute once. Experience Index uses named sensors, configurable impact minutes, and 5-minute bucket cost allocation.
If you compare both scores for the same user or device, do not expect them to match exactly. Instead, expect Experience Index to reflect a more specific set of issue detections and bucketed impact rules, while Health Score reflects impacted active time from the legacy health categories.