Steel Plant Root Cause Analysis with AI and Voice Interviews

The Evidence That Disappears First

Parts can be bagged and data can be exported, but what people saw and heard starts to change within hours. Memory research has long shown that recall weakens with delay. Talking it over also changes it: in a 2003 study by Gabbert, Memon and Allan, 71% of witnesses who discussed an event with a co-witness later reported details they had only picked up in that discussion. In a steel plant, the crew talks it through at the pulpit, in the canteen and at handover. Ask our reliability team how to protect that evidence.

An Interview Built on the Cognitive Interview

The cognitive interview, set out by Fisher and Geiselman, uses open questions, mental context and a full free account to draw out more detail. Meta-analyses by Köhnken and colleagues (1999) and Memon and colleagues (2010) found it brings out more correct detail than a standard interview, with a small rise in errors, so answers must still be checked. The RCA Assistant follows the same pattern by voice, one person at a time, and reads each key fact back. Hear a sample interview in a voice interview walkthrough.

Worked Example: An F4 Gearbox Trip, Second by Second

This illustration follows a finishing stand gearbox failure on a hot strip mill. The assistant merges four sources into one timeline: the CMMS, the historian, PLC alarms and voice interviews. Where an account and the data disagree, it flags the conflict instead of choosing a winner, and the next interview asks about it. Ask our support team which of your data sources can feed a timeline.

Failure Investigation Starts With Five Kinds of Evidence

The PROACT method starts with preserving evidence and sorts it into five P's: Parts, Position, People, Paper and Paradigms. Apollo-style cause-and-effect charting adds a useful rule: every cause on the chart needs evidence, and each effect usually has at least two causes, an action and a condition. The matrix shows how the five P's apply to the F4 example. Plan your own evidence routine in an investigation setup session.

A 5-Why Draft Where Every Step Has Evidence

A 5-Why is only as good as the proof behind each answer. The assistant drafts the chain from the timeline and marks the evidence for each step, so the team can see where it is solid and where it is still a guess. In this example the chain splits into two root causes, a missing procedure step and an alarm people had learned to ignore. Review a draft with our reliability engineers.

A Fishbone Draft That Shows What Is Proven

A fishbone keeps the team from stopping at the first likely cause. The assistant sorts every candidate into the usual categories and marks it as supported, open or ruled out, based on the evidence in the case file. Open items become tasks, such as an oil sample, rather than opinions. See a live fishbone in a fishbone draft demo.

Actions on the CAPA Kanban Until They Are Proven

Many investigations end with a good report and actions that never finish. On the CAPA kanban, every action has an owner and a due date, and it can't close until someone checks that it worked. The board below shows the F4 actions a week after the event. Set up your own board with our support team.

Match the Depth of Investigation to the Event

Not every stop needs a full team RCA. A clear trigger rule saves effort on small events and makes sure serious ones get the full treatment. Your plant sets the thresholds. The tiers below show a common pattern, and the assistant starts voice interviews automatically for every tier. Agree your own trigger rules in an RCA rollout session.

Count the Hours an Investigation Really Takes

The biggest value of better RCA is the repeat failure that never happens, which you should judge on your own records rather than a promised figure. The part you can measure now is investigator time. The worksheet uses assumed inputs to show the arithmetic only. Our team can help you build the case with your own data.

Four Measures That Show RCA Is Working

A plant manager doesn't need to read every report to know whether investigations are improving. These four measures, reviewed monthly, show speed, quality and follow-through. Set baselines for them in a reliability review call.

Voice Interviews and Timelines Running Inside the Plant

A pre-configured NVIDIA AI server ships racked and ready, with speech models, timeline merging and the RCA Assistant pre-loaded, so crew audio never leaves the site. You rack it, plug in power and Ethernet, and the AI is live. Confirm the scope with our integration team.

RCA Software for Steel That Does the Legwork

The RCA Assistant handles the slow, easy-to-skip parts of an investigation so engineers can spend their time on judgement. See it on a real steel breakdown in an RCA assistant demo.

Steel Plant RCA Questions From Reliability Leaders