Summarize condition clues with HI

Combine EQ-005's sensor, inspection, DGA, and operating clues into a Health Index and read it separately from thermal anomalies.

Question for this chapter

How can unlike test results become one view of an asset's current condition?

Why this matters now

Sensor readings, inspections, DGA, and load factors use different units and arrive at different intervals. A decision based on only one value can miss deterioration shown by another clue.

A Health Index (HI) is like a summary page in a medical checkup. It converts several checks to a 0–100 scale and weights them into one view of current condition. Higher is healthier in this scenario. HI does not directly state remaining life or a failure date.

Try it

Open the health_assessment pipeline and select Run. It executes two code assets:

thermal_anomaly_detection combines Z-score, IQR, and CUSUM clues from temperature readings.
health_index_evaluation combines equipment age, sensors, inspections, DGA, and operating load.

Korean Portal showing both thermal-anomaly and Health Index stages succeeding in the health-assessment pipeline — The Portal capture is in Korean. Verify both connected analysis stages, their outputs, and the successful run.

When the run completes, find EQ-005 in health_index_scores.

Successful result

The HI output has one row per asset, ten rows total, with six B grades and four C grades. EQ-005 contains these values.

Condition clue	Score	How to read it
DGA	65.7852	Latest oil sample compared across six dissolved gases
Electrical	74.8548	Partial-discharge and vibration condition score
Oil quality	95.1411	Separate summary of CO and CO2 components
Visual inspection	100.0000	The one current inspection record is `normal`
Operating load	60.6071	Load factors compared with the reference band
Age factor	0.971206	Installation age multiplier applied to the combined score
Overall HI	76.2767 (B)	Current condition summarized across available clues

thermal_anomaly_results has ten rows and five assets with anomaly_flag = true. EQ-005 is false with an anomaly score of 0.2000.

Korean Portal Health Index results showing EQ-005 component scores, overall HI, and grade — The Portal capture is in Korean. Read EQ-005's component evidence with overall HI 76.2767 and grade B.

Read the result

A false thermal-anomaly flag does not show that EQ-005 needs no maintenance. Thermal anomalies cover one type of temperature signal, while HI also uses DGA, electrical condition, inspections, load, and age. Here, a normal inspection and strong oil-quality score combine with weaker DGA and load scores to produce HI 76.2767, grade B.

Deep dive — how are weights handled when a signal is unavailable?

DGA exists only for transformers, so GIS and cable assets have no DGA score. The current code does not replace an unavailable category with zero. It divides by the weights of available categories instead. When comparing overall HI, also check which component evidence was present.

Next decision

HI summarizes current condition but does not show how long the asset may continue operating. Next, use failure history and operating conditions to estimate RUL and read it as a range.