arXiv:2610.17786Industrial diagnosisOpen source

Agentic4PDM

Host-Governed Evidence Admissibility
for Industrial Fault Diagnosis

Nam V. Nguyen1 · Hoang Van Truong1 · Hieu D. D.1
Nguyen Duy Khuong1 · Quang Pham2 · Tung Kieu3

1FPT Corporation2Independent Researcher3Aalborg University

When a diagnosis remains ambiguous, what should an agent investigate—and how much should each result influence its decision? Agentic4PDM combines case-specific investigation with a deterministic host that governs how evidence is acquired and used.

01 Compare the signal with a labeled reference from every class.

02 Select measurements for the ambiguity of the current case.

03 Check evidence roles before proposing a diagnosis.

48Signal properties
25Default tools
3Host checks
ADAPTIVE INVESTIGATION
The agent investigates. The host governs.A query signal and class-balanced references feed the analysts and Judge. The host governs requests, influence roles, and finalization. The system reports a class with an investigation record.A question, then evidence.QUERY SIGNAL + LABELED REFERENCES Analysts → JudgeCompare · identify ambiguity · propose tools Deterministic hostRequestInfluenceFinalization Diagnosis + recordClass · evidence roles · admission status
Agent reasoning Host governance

Video demonstration

See Agentic4PDM in action

A three-minute narrated overview: the problem, the idea, how the agent reaches a decision under CCGA, and the results.

Narrated overview · 3:11 · up to 1080p · Download MP4 ↓

The framework

Freedom to investigate.
Discipline in evidence use.

LLM agents identify the questions that remain unresolved. Contract-checked gated adjudication (CCGA) controls which measurements may run, how results may support a class, and whether the proposed diagnosis is admitted.

The host freezes comparative reports before the Judge begins sample-specific investigation. Every measurement and its influence role are retained in the investigation record.
01

Request gate

Declare unresolved signal properties, receive compatible tools, commit to a complete batch, and execute. The host checks coverage and prevents revisiting measured properties.

Declare → Offer → Commit → Execute
02

Packet & influence gate

Test each tool on known-label controls. Usable results become corroborative if every control is recovered, or advisory otherwise. Failed or ambiguous packets are excluded.

Checked support or advisory information
03

Finalization

Admit a proposal only if its class is in the initial candidate set and a quantitative measurement round is complete. Otherwise, return it for revision within the step budget.

A class + its admission status

Standard mode

Pretrained embeddings and labeled references, plus SVM and XGBoost predictions as hypotheses to investigate. The main results use this mode.

Training-free mode

Pretrained representations and labeled references, with no task-specific fitted diagnostic classifier. Evaluated separately in the appendix.

Read the full abstract
We study industrial fault diagnosis as a classification task that assigns sensor time-series windows to predefined health states or fault types. Scarce labels and changing operating conditions make repeated training of specialized classifiers costly. Yet structures such as periodicity, trends, and transients can remain diagnostically informative and be examined through reusable analytical tools. LLM agents can select and interpret these tools, but fixed rules or training-derived guidance may not resolve each signal’s ambiguity, while unconstrained interpretation may overstate weak or conflicting results. We introduce Agentic4PDM, a framework that separates adaptive investigation from control over evidence use. LLM agents compare each signal with labeled references from every candidate class, identify unresolved distinctions, and propose follow-up measurements. A deterministic software controller, called the host, enforces contract-checked gated adjudication (CCGA): it checks requests, requires commitment to a complete tool batch before results are observed, and assigns evidence roles based on tool checks against labeled references. These roles distinguish corroborative support from advisory information. The Judge Agent proposes a diagnosis, while the controller checks protocol compliance and records the investigation. Agentic4PDM supports training-free diagnosis using pretrained representations and labeled references without task-specific diagnostic models, and a standard setting that additionally investigates trained-model predictions. Experiments on selected bearing and motor diagnosis challenges and an unfiltered industrial test set supplied by our customer show gains in aggregate macro F1 over the evaluated diagnostic and agentic baselines. Ablations further support the value of the governed workflow.

Empirical results

Three complementary tests

Agentic4PDM achieves the highest aggregate macro-F1 among the evaluated methods across public benchmark challenges and the full external customer test set.

Regime coverage · GRS

59.20%Unweighted public-dataset average

Hard cases · BFH

47.47%Unweighted public-dataset average

Customer test · Bel

73.95%All 330 test samples

Macro-F1 (%) · standard mode · values from the paper

GRS selects diverse regimes; BFH selects cases where many baseline models fail. Bel preserves the customer-defined test distribution without either selection procedure.
2,048 observations / window50 training samples / classQwen3.6-27B for all agentic methods
Explore the detailed benchmark results

Detailed results

A closer look

What the investigation changes

Beyond aggregate scores, the paper examines prediction revisions, sample-specific plans, the contribution of evidence-handling controls, and whether simpler uses of the same evidence can match the workflow.

01 / Beyond fitted-model predictions

Agreement is a starting point

When SVM and XGBoost initially agree, Agentic4PDM can still correct their shared errors. On PU and MCC5 GRS, the consensus analysis reports a net accuracy gain of 7.97 percentage points, after accounting for new errors introduced.

Fitted-model predictions serve as hypotheses for further investigation.

02 / Sample-specific investigation

Different cases, different questions

Agentic4PDM produces 31 distinct plans on PU and 50 on MCC5, compared with one fixed plan for FETA and limited variation in ZARA.

Evidence acquisition varies with the case. This observation does not by itself show that plan diversity causes the performance gains.

03 / Component ablation

Both evidence access
and governance matter

On PU GRS, replacing class-balanced retrieval or removing both governance gates substantially lowers performance. All variants use the same evaluation setting.

PU · GRS · standard mode
VariantAccuracyMacro-F1Δ F1
Full workflow47.2438.54—
Global top-K retrieval37.2029.89−8.65
No Analyst reports46.3537.72−0.82
Both gates removed36.3130.53−8.01
No request gate39.9633.35−5.19
No packet & influence gate42.6036.70−1.84
No finalization45.4038.02−0.52

Scores are percentages. Δ F1 is the change in percentage points from the full workflow.

04 / Simpler alternatives

Simple shortcuts do not reproduce the workflow

Could the same result come from voting over the evidence the Judge already has, or from one strong measurement? The paper tests both. Neither matches the full workflow.

(a) Flat plurality vote · Appendix C.4Voting over labels already in context The NAAgent and ABAgent outputs, the final LBAgents conclusion, and the SVM and XGBoost predictions, combined by plurality. Macro-F1 on the same covered samples.
Flat pluralityAgentic4PDM
MCC5
48.26
54.09
+5.83
PU
28.45
37.90
+9.45
UO
85.00
87.38
+2.38

Coverage: 77.7% of samples on MCC5, 84.1% on PU, 89.5% on UO (samples where the vote gives a prediction rather than a tie).

(b) Best single tool · Appendix DOne strong measurement does not transfer The best of the 25 default tools on each dataset, scored unchanged on the other two. Macro-F1 (%) on GRS.
ToolMCC5PUUOMean
Windowed profilebest on MCC536.1535.2230.1733.85
Crossing-run statisticsbest on PU22.8937.9416.7325.85
Distribution KSbest on UO31.7832.7860.0241.53
Agentic4PDMfull workflow52.9338.5486.1259.20

Outlined cell: the dataset where the tool was selected. Crossing-run statistics reaches 37.94 on PU but falls to 22.89 on MCC5 (−15.05) and 16.73 on UO (−21.21).

Neither fixed aggregation of the initial evidence nor one strong measurement reproduces the full workflow. This is consistent with the value of choosing and combining measurements for the current case.

Resource use & evaluation scope

Agentic4PDM is intended for on-demand investigation of difficult cases. The paper reports higher token use alongside stronger aggregate diagnostic performance.

Mean recorded resources per query
MethodTokensTime (s)LLM callsEst. API charge
ZARA7.83k98.204.0$0.0129
FETA72.67k1,078.598.0$0.0575
Agentic4PDM102.36k1,645.7917.4$0.0989

Timer scopes differ between implementations. Charges use the paper’s assumptions: $0.60 per million input tokens and $3.60 per million output tokens. These are estimates, not observed bills or total deployment costs.

Training-free uses labeled references. It omits fitted diagnostic classifiers while retaining pretrained representations.

Admission is a protocol flag. Every sample receives a class; the flag is not a probability of correctness.

The evaluation has a defined scope. GRS/BFH are selected challenges. Bel is one full external customer test set, not a fleet-wide deployment study.

Authors

Research team

FPT Corporation · Independent Researcher · Aalborg University

HT

Hoang Van Truong

FPT Corporation

HD

Hieu D. D.

FPT Corporation

NK

Nguyen Duy Khuong

FPT Corporation

QP

Quang Pham

Independent Researcher

TK

Tung Kieu

Aalborg University

FPT CorporationAalborg University

BibTeX citation

@misc{nguyen2026agentic4pdmhostgovernedevidenceadmissibility,
      title={Agentic4PDM: Host-Governed Evidence Admissibility for Industrial Fault Diagnosis}, 
      author={Nam V. Nguyen and Hoang Van Truong and Hieu D. D. and Duy Khuong Nguyen and Quang Pham and Tung Kieu},
      year={2026},
      eprint={2610.17786},
      archivePrefix={arXiv},
      primaryClass={cs.AI},
      url={https://arxiv.org/abs/2610.17786}, 
}

arXiv preprint arXiv:2610.17786 (v1, 13 October 2026), cs.AI.

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