11.3 Technical Report Writing, Data Trending, and Communicating Deficiencies
Key Takeaways
- Level III task 3.4.1 requires preparing and reviewing technical reports, and Level IV 4.4.1 requires integrating Level II and III reports into a single deliverable.
- A deficiency statement must give the location, the measurement, the comparison basis, the probable cause, the consequence, and a recommended action with urgency.
- Trending detects degradation from the rate of change long before an absolute limit is reached, which is why baseline data is the most valuable record in a maintenance program.
- Level II task 2.5.1 grades business communication, including the parts of a business letter and clear written communication with the client.
- Reports must be written for two audiences at once: the technician who will perform the repair and the manager who will authorize it.
Technical Report Writing, Data Trending, and Communicating Deficiencies
Quick Answer: Reporting is graded at every level. Level II 2.4.4 requires preparing "simple reports on daily activities" and 2.5.1 requires maintaining business communications, with the knowledge listed as "parts of a business letter" and "proper sentence structure." Level III 3.4.1 requires "prepare and review technical reports." Level IV 4.4.1 requires "integrate Level II and III reports" into a coherent deliverable. The report is the product. Everything else is the process that produced it.
1. Why the report is the deliverable
A client does not buy test measurements. They buy a decision-quality answer to a question: is this equipment safe to energize, is it fit for another service interval, and what do I need to do about it. The measurements are the evidence; the report is the answer.
That framing has a practical consequence: a technically flawless test program that produces an unreadable, unactionable report has failed to deliver. Conversely, a clear report that surfaces the two findings that matter, in language a maintenance planner can act on, delivers most of the value.
2. Report structure
| Section | Content |
|---|---|
| Executive summary | The conclusion, the count of deficiencies by severity, and the top recommendations — one page, readable by a manager |
| Scope | What equipment was tested, to which standard, on what dates, by whom, under what authorization |
| Limitations and exclusions | What was not tested, and why — access denied, outage window closed, component could not be isolated |
| Methodology | Tests performed, standards applied, instruments used with serial numbers and calibration dates |
| Results | Tabulated data by equipment, with conditions and corrections shown |
| Deficiencies | Each finding, severity-ranked, with the elements in Section 3 |
| Recommendations | Prioritized, with urgency and, where possible, an owner |
| Appendices | Raw data, thermograms, photographs, relay setting reports, curves, calibration certificates |
The limitations section is the one candidates undervalue and the one that protects everybody. A report silent about an untested item implies it was tested and passed. If a failure later occurs there, the silence is indefensible. State plainly: "Cubicle 7 could not be tested; the tenant declined the outage. Recommend testing at the next available opportunity."
3. Writing a deficiency that gets acted on
A deficiency statement needs six elements. Omit any one and the finding will not be actioned correctly.
- Location — specific enough for a crew to walk to it. "Switchgear SWG-2, cubicle 4, breaker load-side B-phase lug."
- The measurement — what was found, with units and conditions.
- The comparison basis — what it was measured against, named. "Referenced to A and C phases at identical load."
- Probable cause — the technician's judgement. This is the element that distinguishes a report from a data dump.
- Consequence — what happens if nothing is done, and on what timescale.
- Recommended action with urgency — what to do, and when.
Compare:
Weak: "Hot spot found on SWG-2."
Strong: "SWG-2, cubicle 4, breaker load-side B-phase lug: 22 °C above A and C phases at identical load (450 A of 600 A rating), projected to approximately 39 °C at full load. Probable cause is a loose or corroded compression lug. Left uncorrected this will progress to thermal runaway and an open circuit or fire. Recommend de-energizing at the earliest opportunity, inspecting and cleaning the connection, re-torquing to the manufacturer's value, and re-surveying under load. Given the projected full-load rise this is a major discrepancy under NETA Table 100.18 and should not wait for the next scheduled outage."
The second version can be scheduled, resourced, and closed out. The first cannot.
Severity ranking must be consistent and explained. Whatever scheme is used — critical / major / minor, or a numbered priority — define it in the report so that "Priority 2" means the same thing to every reader.
4. Trending
Trending is what converts a test program from a compliance exercise into a predictive one. The absolute value tells you where you are; the rate of change tells you where you are going and how fast.
Worked example. A transformer winding's insulation resistance, all values corrected to 20 °C:
| Year | Corrected IR |
|---|---|
| Commissioning | 5,000 MΩ |
| +3 years | 4,200 MΩ |
| +6 years | 3,100 MΩ |
| +9 years | 1,800 MΩ |
Every one of these comfortably exceeds any table minimum. Taken individually, each year's test is a pass. Taken as a trend, the winding has lost 64 % of its insulation resistance and the decline is accelerating — the losses per three-year interval are 800, 1,100, and 1,300 MΩ. That is a unit heading for trouble, and the finding is invisible to anyone comparing single readings against a limit.
Requirements for valid trending:
- Consistent test conditions — same test voltage, same connections, same duration, same guard configuration. Change any of them and the comparison is broken.
- Consistent correction — everything normalized to the same reference temperature.
- Consistent instrument type where practical, with the instrument recorded.
- A baseline. This is why acceptance testing has value long after commissioning: the ATS data set is the baseline. A maintenance program on equipment with no commissioning data is working blind for its first several cycles.
What to trend: insulation resistance, PI, power factor and capacitance, contact and bolted-connection resistance, winding resistance, DGA gas concentrations and rates of gas generation, oil quality parameters, battery cell impedance and voltage, thermographic ΔT at identical load, breaker timing and travel, and relay as-found deviation.
For DGA in particular, the rate of gas generation is more diagnostic than the concentration. A stable elevated level is a healed old event; a rapidly rising level at a lower absolute concentration is an active fault.
5. Writing for two audiences
Every report has two readers with different needs:
- The technician or maintenance planner needs specificity, numbers, locations, torque values, and part identification.
- The manager or owner needs the decision: what is the risk, what does it cost, when must it happen, what happens if we defer.
Serve both by putting the decision-quality summary at the front and the technical detail behind it. Do not make a manager read forty pages of tabulated micro-ohm readings to discover that one breaker should not be re-energized.
Language practices that matter:
- Define acronyms on first use. DLRO, PI, TTR, VLF, GST, and MCOV are not universal vocabulary outside the trade.
- State facts and judgements separately. "The measured value is 22 °C above the reference phases" is a fact. "Probable cause is a loose lug" is a judgement. Marking the difference is honest and it protects the technician if the judgement turns out wrong.
- Avoid absolute claims the data does not support. "The equipment is safe" is a claim about the future. "The tests performed on the date shown produced results within the applicable criteria" is what the data actually supports.
- Write in plain, direct sentences. Level II's outline literally grades "proper sentence structure" and the ability to "read and write standard English."
6. Integrating multi-crew reports at Level IV
Level IV's task is integration, and the difficulties are real:
- Reconcile inconsistent formats and units across crews into one presentation.
- Resolve contradictions. Two technicians reporting different values for the same connection must be reconciled before publication, not published side by side.
- Identify patterns no single crew could see. Three crews each reporting one loose connection on a different lineup have collectively found a systemic torque or workmanship problem, and only the integrator sees it.
- Normalize severity ranking so a "critical" from one crew means what a "critical" from another crew means.
- Produce one coherent set of prioritized recommendations rather than three parallel lists.
That pattern-recognition step is where a Level IV report earns its value: converting a pile of individual findings into a statement about the condition of the installation.
Exam trap: A question asks whether a maintenance test that produced a value well above the NETA minimum needs to be reported as a concern, given a series of prior readings showing steady decline. The absolute value passing is not the whole answer — a consistent and accelerating downward trend is a reportable finding regardless of where the current reading sits relative to the table.
A transformer winding's corrected insulation resistance has fallen from 5,000 MΩ at commissioning to 1,800 MΩ over nine years, with every reading well above the applicable table minimum. How should this be reported?
Which element is most often missing from a report and most likely to become indefensible after a failure?
Why is the rate of gas generation more diagnostic than the absolute gas concentration in dissolved gas analysis trending?