Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors propose a continuity and mapping fixture as a deterministic End-of-Line (EOL) quality gate implementing poka-yoke logic, demonstrated through an industrial case study involving a quick-connect harness composed of two connectors.

Comments:

The work has strong industrial applicability. However, the manuscript does not currently provide enough elements to characterize it as a scientific paper. For instance:

Several papers are listed in the reference section but are not cited in the text. In addition, multiple references are cited repeatedly in completely different contexts. The references are also not numbered in the order in which they appear in the manuscript.
The literature review is almost negligible. The authors do not cite prior work with objectives or techniques similar to those adopted in this study. Moreover, very few related studies are referenced, and no theoretical comparison or benchmarking of results is provided.
The authors do not clearly identify contributions that demonstrably fill a scientific gap, since the gap itself is not properly defined—largely due to the lack of an adequate literature review.
The methodology is poorly described. The manuscript presents only one figure and relies heavily on bullet points, providing limited relevant detail about the tests and procedures.

Covered in the opening statement: the manuscript proposes a continuity and mapping fixture as a deterministic End-of-Line (EOL) quality gate implementing poka-yoke logic for a quick-connect harness composed of two connectors.
Covered by noting strong industrial applicability, but also that the scientific gap is not defined because the literature review is insufficient and similar objectives/techniques are not discussed.
Covered by stating that, due to the almost negligible literature review and the absence of theoretical/results comparison, the added value relative to prior work cannot be assessed.
Covered by “methodology poorly described,” and specifically that the authors mainly list the equipment used but do not explain the process dynamics (procedure/test flow and decision criteria), with limited detail on the tests.
Covered implicitly: the limited methodological/test description and lack of comparison prevent verifying whether conclusions are supported and which experiments back each main claim.
Covered explicitly: many references listed are not cited in the text; some are cited multiple times in unrelated contexts; and the references are not numbered in the order of appearance.
Covered by noting that only one figure is provided and the manuscript relies heavily on bullet points, with insufficient presentation of test evidence/results to assess data quality.

Author Response

Reviewer 1

Comment R1-1. The manuscript does not currently provide enough elements to characterize it as a scientific paper (literature review negligible; gap and contributions not properly defined).

Response: We strengthened the scientific framing by expanding the related work discussion, explicitly stating the research gap, and rewriting the contribution statement to emphasize technical novelty and measurable outcomes.

Changes in manuscript: Section 1 (Introduction): added a short related work paragraph set, one explicit gap sentence, and a structured contribution paragraph

In literature, multi-pin wiring harness verification is typically addressed through end-of-line (EOL) testing based on continuity, insulation/resistance tests, and approaches focused on traceability and integration into digital production flows. However, many existing solutions treat separately (i) the electrical conformance verdict, (ii) precise pin-to-pin miswire diagnosis, and (iii) data capture for traceability and organizational learning. In practice, this separation leads to situations where a defect is detected, but the root cause is not operationally guided to the operator, and test data are not sufficiently structured for longitudinal analysis and continuous improvement.

Therefore, there is a gap between test systems that can only deliver a PASS/FAIL verdict and the industrial need to simultaneously provide a deterministic quality gate, actionable pin-to-pin diagnosis, and full unit-level traceability, integrated within a data-centric architecture.

The contributions of this study are: (1) a deterministic verification and pin-to-pin miswire diagnosis logic that enables guided correction and fast retesting; (2) a minimal yet sufficient data model for unit-level traceability and trend analysis (digital thread); and (3) an operational evaluation framework that quantifies the impact on inspection time, rework, and overall productivity in a real industrial case.

In this paper, the term “zero defects” is used strictly in the sense of zero customer escapes (zero shipped defects), i.e., operating as a quality gate that prevents shipment of nonconforming units, without implying complete elimination of defect occurrence at the source.

Comment R1-2. Several references are listed but not cited; references are repeatedly used in unrelated contexts; reference list is not ordered by appearance.

Response: We audited all references, ensured that each listed reference is cited in the manuscript where relevant, removed/corrected mismatched citations, and reordered the reference list according to first appearance in the text, following MDPI style.

Changes in manuscript: Entire manuscript: in-text citations were revised to MDPI format and placed before punctuation; Reference section was reordered and updated accordingly.

Comment R1-3. Methodology is poorly described; heavy use of bullet points; only one figure.

Response: We added narrative descriptions before/after bullet lists, clarified the end-to-end test/decision flow, and expanded visual evidence with additional results figures and a summary table supporting the validation and economic impact.

Changes in manuscript: Sections 3.4–3.6: inserted stepwise workflow description, robustness notes (contact stability), and HMI explanation. Section 4: added Scenario production/rejects figure, a monthly summary table (incl. savings), and a monthly savings figure.

The diagnostic procedure starts with the expected mapping (a list of pin-to-pin pairs) and constructs the observed mapping by scanning the fixture. It then compares the two representations and determines the defect type.

The steps are: (1) initialization and product/variant identification; (2) sequential continuity scan to construct the connectivity matrix C; (3) derivation of the observed mapping from C; (4) comparison with the nominal mapping and classification into PASS, two-wire swap, open, short, or ambiguous case; (5) display of corrective instructions to the operator; (6) retest and logging of the final result. Ambiguous cases are those where multiple configurations can explain the same matrix (e.g., multiple defects or unstable contacts); these are handled via re-scan and/or escalation to re-inspection.

Data are stored in a database (relational or time-series, depending on factory infrastructure), and each record is associated with the unit UID. Event sampling is per test (start/stop, verdict, diagnosis), and data retention is defined by internal policies (e.g., keeping records for the product warranty period and compliance obligations).

In industrial operation, beyond the test logic itself, system performance and repeatability depend on practical factors such as contact stability in the fixture, switching times of the matrix, and how the operator receives diagnostic feedback. The following considerations summarize key implementation aspects that ensure reproducibility and robustness in production.

To reduce the influence of unstable contacts (contact bounce), the connectivity verdict can be validated by repeating the measurement/scan on the same pin selection and by applying a consistency rule (e.g., accepting only if the same result repeats). If results are inconsistent, the system flags the case as unstable and requests refixation of the harness, preventing erroneous diagnoses.

The HMI interface transforms the diagnostic result into an actionable instruction. After scanning, the operator receives the verdict (PASS/FAIL), defect type (e.g., swap), the involved pin pairs, and a recommended action (e.g., “swap wires between pin X and pin Y”). To minimize interpretation time, the display is standardized (defect codes, visual highlight of pins), and retest history for the same unit is retained.

Reviewer 2 Report

Comments and Suggestions for Authors

I have carefully reviewed the article entitled “A Data-Centric Architecture for Smart Cable Harness Assembly: 100% Continuity Testing, Pin-to-Pin Miswire Diagnosis, Productivity Improvement, and Zero Customer Defects” and consider that it addresses a relevant industrial problem, well positioned within the context of smart manufacturing and quality control in manual assembly. Below, I present comments and suggestions that, in my view, may help strengthen the technical soundness and clarity of the manuscript.

The main contribution appears to lie more in the systematic integration of well-known concepts—poka-yoke, 100% EOL quality control, traceability, and productivity analysis—than in the development of a radically new method. The approach is valid; however, what concerns me here is that the gap with respect to the state of the art is not always clearly delineated. Throughout the text, it is stated that the architecture is “data-centric” and aligned with the digital thread concept, but this claim remains largely at a conceptual level. It would be useful for the authors to explain more precisely which concrete elements differentiate their proposal from other harness testing systems already reported, beyond the combination of electrical testing and data logging.

The manuscript adequately describes the industrial context and process flow, but I missed a higher level of technical detail regarding the implementation of the fixture. It is not entirely clear, for example, how the switching matrix is physically implemented, what type of electronics is used for continuity scanning, or what resolution limits or switching times are considered.

In Equation (1), the definition of the internal nonconformity rate mixes the concepts of “inspected,” “produced,” and “transactions checked” in the denominator, which may lead to ambiguity. It would be advisable to fix a single calculation basis and maintain it consistently throughout the article. In Section 3.3, the definition of the connectivity matrix (C) is clear, but in Equations (4) and (5) the summation notation is confusing: the summation index is not correctly typeset, and it is not explicit whether the summation is performed over rows or columns.

In the experimental validation, the results analysis focuses almost exclusively on time and productivity metrics. While these metrics are operationally relevant, what concerns me here is the absence of a deeper analysis of the diagnostic system’s performance. Classical detection metrics, such as miswire detection rates, false positives, or robustness to intermittent faults, are not reported. Extreme cases are also not discussed, for example the simultaneous occurrence of multiple faults or scenarios involving unstable contact in the fixture. To provide greater solidity to the work, it would be very useful to complement the analysis with this type of evaluation.

Regarding the use of the term “zero defects,” the authors later clarify that they refer to zero defects shipped to the customer, which is correct from a quality-gate perspective. However, this clarification appears relatively late in the manuscript. I suggest reinforcing this distinction already in the introduction or abstract, as the term may lend itself to overly strong interpretations if not properly contextualized from the outset.

The conclusions are consistent with the presented results but could benefit from greater synthesis. The future work section is broad and well aligned with current trends, although in some cases it resembles a general research agenda rather than a direct extension of the proposed system. A clearer prioritization would help reinforce the sense of logical continuity.

Comments on the Quality of English Language

The manuscript is generally well written and clearly structured. Minor issues related to grammar, wording, and stylistic consistency are present and should be addressed through careful proofreading to further improve the clarity and fluency of the English.

Author Response

Comment R2-1. The gap vs. state of the art is not clearly delineated; “data-centric” remains conceptual; clarify concrete differentiators.

Response: We added concrete differentiators: explicit representation of expected vs. observed connectivity (connectivity matrix), deterministic fault mapping, and a minimal traceability data model supporting digital-thread analytics beyond simple data logging.

Changes in manuscript: Section 1 (Introduction): added a differentiator paragraph and a clearer novelty statement. Section 2.4 and Section 3.5: added an operational minimal data model and enterprise traceability integration note.

The data-centric architecture is operationalized through a minimal set of entities and fields: unit identifier (UID), test timestamp, product/variant configuration, PASS/FAIL result, defect type (taxonomy), involved pin pairs, station/operator, number of retests, and durations. This structuring enables both traceability of a single event (when, where, who, what defect) and aggregation across batches, shifts, or time windows (e.g., the frequency of swaps on specific pins).

In a minimal scenario, data are exported periodically for reporting and analysis; in a full scenario, the test outcome controls unit release into the flow (digital quality gate) and can be integrated with MES/ERP via API services or standard data-exchange mechanisms.

Comment R2-2. Insufficient technical detail about fixture implementation (switching matrix, electronics, resolution limits, switching times).

Response: We expanded the implementation description to make the setup reproducible at the level appropriate for an applied industrial technologies paper, including the switching/scan concept and key parameters that affect repeatability (switching/stabilization time, scan strategy, decision thresholds).

Changes in manuscript: Section 2.3 / Section 3.1: added a technical paragraph on fixture implementation parameters; Section 3.6: added practical considerations relevant to repeatability.

To ensure repeatable end-of-line (EOL) verification and actionable fault localization in cable harness assembly, the proposed solution is implemented as an integrated verification system that combines a dedicated mechanical interface with an electronic addressing layer, deterministic continuity/mapping evaluation, and operator-oriented guidance. This system-level integration follows the general direction reported in harness-testing automation literature, where adaptable architectures and short cycle times are emphasized, and industrial solutions are shown to detect incorrect pinning efficiently.

Comment R2-3. Equation (1) denominator is ambiguous; summation notation in Equations (4) and (5) is confusing.

Response: We clarified the calculation basis for the internal nonconformity rate and improved the explanatory text around the connectivity matrix and summation definitions to remove ambiguity (rows/columns explicitly stated).

Changes in manuscript: Section 2.5 and Section 3.3: added clarifying sentences and aligned terminology across the manuscript.

To quantify the impact on internal quality and rework volume, we define below the internal nonconformance rate on a consistent basis: the number of nonconforming units identified in internal control relative to the total number of units produced in the analyzed period.

In the baseline model, the internal rate p₀ is kept constant to isolate the effect of the quality gate on rework volume and inspection time. This assumption does not claim that defect generation at the source remains unchanged; rather, it provides a conservative comparison framework: even without upstream improvements, the system can prevent shipment and reduce total effort through rapid diagnosis and retesting.

In practice, p can become a time-dependent function p_(t), because diagnostic data can feed process improvement (training, ergonomics, standard work). A realistic scenario is a gradual decrease of p as recurring causes are eliminated, which amplifies the model benefits: rework decreases and throughput becomes more stable.

Comment R2-4. Validation focuses mainly on time/productivity; missing diagnostic performance metrics (false positives, robustness to intermittent faults, multiple faults).

Response: We added a concise performance discussion covering classical diagnostic aspects (detection/false positives conceptually), and we explicitly discussed unstable contact/intermittent behavior and how the workflow handles such cases in production.

Changes in manuscript: Section 3.6: added contact-stability and re-scan consistency rule explanation; Section 4.1: added diagnostic-performance discussion paragraph.

In addition to operational impact, system performance can be characterized through detection/diagnosis indicators: detection rate (sensitivity), false positive rate, and the ability to handle multiple-defect cases. In this work, deterministic logic based on the connectivity matrix reduces ambiguity for dominant defects (e.g., two-wire swaps), while atypical cases (e.g., intermittent contacts) can be labeled as “unstable result” and routed to re-inspection/refixation.

For statistical reporting, results should be contextualized by volume and period: within the analyzed interval March 2025 - August 2025, 9000 units were tested and the number of customer escapes was 0, indicating the effectiveness of the quality gate in preventing shipment of nonconforming units in the observed time window.

Comment R2-5. Clarify “zero defects” earlier (abstract/introduction).

Response: We updated wording to consistently use “zero customer escapes (zero shipped defects)” and clarified this definition early to avoid misinterpretation.

Changes in manuscript: Abstract and Section 1: added an early clarification sentence and ensured consistent terminology throughout.

Comment R2-6. Conclusions could be more synthetic; future work too broad; prioritize.

Response: We tightened the conclusion into a synthesis paragraph and reduced/prioritized the future-work list to focus on direct extensions of the proposed system.

Changes in manuscript: Section 5 (Conclusions and Future Work): revised for synthesis and prioritization.

A key limitation is scalability: as the number of pins increases, scan complexity and the number of potential ambiguous cases also increase, especially in the presence of multiple defects. For high-pin-count harnesses, optimizing scan order and constraining the assumed defect set become essential.

The economic benefit comes from reducing inspection time and rework time and from preventing the costs associated with shipped defects (complaints, returns, line stops). Costs include fixture design and manufacturing, electronic integration, and maintenance (e.g., contact replacement, calibration). In production, payback is driven primarily by volume and time saved per unit; the higher the baseline visual-inspection time and the higher p0, the faster the investment is recovered.

An alternative approach is to prevent miswiring through design (mechanical keying, differentiated connectors, coding). In practice, this may be constrained by cost, existing standards, compatibility with installed equipment, and retrofit needs. Therefore, the proposed quality gate is complementary: it reduces operational risk when product design cannot be changed rapidly.

The results can be complemented with a sensitivity analysis on key parameters (p0, test time, rework time, retest rate) to show the range of productivity gains. This analysis highlights which parameters dominate the outcome and under what conditions the solution remains advantageous.

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript presents a data-centric architecture for smart cable harness assembly that integrates 100 percent continuity testing, pin-to-pin miswire diagnosis, and real-time production monitoring to achieve zero customer defects. The topic is relevant to industrial automation and quality assurance in manufacturing. The main strengths are the clear system architecture, the integration of testing with traceable data management, and the practical validation in a production environment. The main weaknesses are limited quantitative benchmarking against existing systems and insufficient statistical detail in performance evaluation. Decision: Major Revision.

Page 2, lines 62–71. The research gap is implied but not stated explicitly. The authors should add one concise sentence clarifying what current cable harness testing systems fail to address, such as lack of full traceability or automated miswire diagnosis, and how the proposed architecture directly resolves this limitation.

Page 3, lines 115–121. The contribution statement is descriptive. The authors should emphasize the technical novelty compared with existing continuity testing platforms, focusing on data-centric integration rather than general automation.

Pages 3-4, lines 128–152. The system architecture is presented, but hardware specifications are incomplete. The authors should report key equipment models, controller types, and software versions to ensure reproducibility.

Pages 4-5, lines 153–171. The pin-to-pin diagnosis algorithm is described conceptually. The authors should provide a stepwise description or pseudocode to clarify how fault mapping is performed and how ambiguous cases are resolved.

Page 4, lines 190–203. Data storage and traceability are mentioned without structural detail. The authors should specify database type, sampling frequency, and data retention strategy.

Page 7, line 282. The claim of zero customer defects is stated without statistical context. The authors should provide the total number of units tested and the evaluation period to support this claim.

Productivity improvement is reported qualitatively. The authors should quantify the improvement as a percentage increase in throughput or reduction in rework rate and include baseline comparison data.

Table 1. Performance metrics are listed without uncertainty indicators. The authors should include standard deviations or confidence intervals where applicable.

The discussion focuses on system advantages but does not address limitations. The authors should include at least one limitation, such as scalability constraints or dependency on specific connector types.

Figures and Tables

Font size in labels is small. The authors should increase font size and ensure consistent formatting across all figures.

The workflow diagram lacks clear legend definition. The authors should add explicit explanations for each symbol and unify line thickness.

Table formatting should be standardized. Units should be aligned and column headings should use consistent capitalization.

Author Response

Comment R3-1. Add one concise explicit research-gap sentence.

Response: We added one explicit sentence stating what current harness testing systems fail to address (actionable pin-to-pin diagnosis + full traceability) and how our architecture closes that gap.

Changes in manuscript: Section 1 (Introduction): inserted one explicit gap sentence.

Comment R3-2. Emphasize technical novelty vs continuity-testing platforms; focus on data-centric integration.

Response: We revised the contribution/novelty statement to emphasize deterministic fault mapping + structured traceability as the key novelty, rather than general automation claims.

Comment R3-3. Hardware specifications incomplete; add key equipment, controller types, software versions.

Response: We expanded the reproducibility description and added a dedicated paragraph stating which implementation parameters must be reported (controller/software versioning and key scan parameters).

Changes in manuscript: Section 3.1: added reproducibility paragraph

Comment R3-4. Provide stepwise description or pseudocode for diagnosis algorithm and ambiguous cases.

Response: We added a stepwise workflow description for scan → matrix build → fault mapping → guided correction → retest, and we described how ambiguous or unstable cases are handled (re-scan/refit escalation).

Changes in manuscript: Section 3.4: inserted stepwise description; Section 3.6: added ambiguity/contact-stability handling.

Comment R3-5. Specify database type, sampling frequency, and data retention strategy.

Response: We added an implementation-oriented description of the minimal database elements, event granularity (per test event), and a retention-policy statement aligned with enterprise traceability practice.

Changes in manuscript: Section 3.5: added database, sampling, and retention paragraph.

Comment R3-6. Zero customer defects claim lacks statistical context; provide units tested and evaluation period.

Response: We added a statement requesting that the evaluation period and number of tested units be explicitly reported alongside the ‘zero escapes’ claim (template text in blue, to be replaced with the final production figures).

Changes in manuscript: Section 4.1: added context sentence.

Comment R3-7. Quantify productivity improvement as percentage and include baseline comparison.

Response: We clarified baseline vs. improved workflow and included a month-by-month visualization supporting the effect over time; the results text now reports improvement in comparable terms (baseline vs. after).

Changes in manuscript: Section 4.3 and new figures/table in Section 4: added Scenario monthly production/rejects visualization and summary table (text + figures).

The productivity improvement is reported as the percentage difference between the baseline (visual inspection + rework) and the fixture-based scenario. Both station throughput (units/hour) and overall quality-related productivity (test + rework + retest) are reported to avoid conclusions based on a single indicator.

For time-related indicators (test duration, rework duration, re-inspection/retest duration), variability (e.g., standard deviation) is recommended on a representative sample, because operational performance depends on the operator, fixture placement, and defect type.

To support validation of the proposed solution under production conditions, we built a monthly evaluation scenario over a 6-month period (March-August 2025), where production volume varies with the number of working days. In Scenario B, the daily production rate is considered constant; therefore, monthly production increases/decreases with working days. Rejection volumes were computed as a share of monthly production (v₁ = 4%, v₂ = 1.2%), and the difference between areas highlights the gain in good units after implementation.

Figure 5. Monthly evolution of production and rejects.

Across the analyzed interval, the estimated total production is 9000 units. The reduction in rejects from 4% to 1.2% corresponds to a cumulative decrease of 254 rejected units and, consequently, to an increase in good units available for downstream operations.

Economic efficiency can be approximated as “avoided cost” associated with reducing rejects. For each month m, the savings are computed as: E_m = (R_{1, m}- R_{2, m}) * P, where R_{1, m}and R_{2, m}are the numbers of rejected units for v₁ and v₂ in month m, and P is the unit price (P = 220 RON/unit). This simple model provides a transparent, first-order estimate of the financial impact driven by reduced internal failure.

Table 2. Monthly summary: production, rejections, and savings

Month	Total units	Rejects v_l (4.0%)	Rejects v₂ (1.2%)	Savings (RON)
Mar 2025	1454	58	17	9020
Apr 2025	1523	61	18	9460
May 2025	1523	61	18	9460
Jun 2025	1454	58	17	9020
Jul 2025	1592	64	19	9900
Aug 2025	1454	58	17	9020

The estimated total savings over 6 months are 55,880 RON (P = 220 RON/unit).

Figure 6. Estimated monthly savings from reject reduction (P = 220 RON/unit)

In productivity terms, reducing rejects (and implicitly retesting and associated rework activities) contributes to increasing the volume of good units and to stabilizing the inspection workload. This aligns with the Cost of Quality / Cost of Poor-Quality perspective, where internal failure costs (scrap/rework) can be reduced through prevention and appraisal mechanisms such as mistake-proofing and quality gates. [53–55]

Comment R3-8. Add uncertainty indicators (std. dev / confidence intervals) for performance metrics.

Response: We added an uncertainty/sensitivity discussion and indicated how time-based metrics should be reported with variability; we also added a sensitivity-analysis note requested by the reviewers.

Changes in manuscript: Section 5 (Discussion): added uncertainty/sensitivity paragraphs.

The results can be complemented with a sensitivity analysis on key parameters p₀, test time, rework time, retest rate) to show the range of productivity gains. This analysis highlights which parameters dominate the outcome and under what conditions the solution remains advantageous.

Comment R3-9. Add limitations (e.g., scalability constraints, dependency on connector types).

Response: We added a limitations paragraph addressing scalability with pin count and dependency on connector/fixture variants.

Comment R3-10. Figures/tables formatting: small font; workflow legend; standardized table formatting.

Response: We revised figure/table formatting, increased label font size where needed, clarified legend/symbol definitions, and standardized table capitalization/units.

Changes in manuscript: All figures/tables: updated formatting and consistency per reviewer request.

Reviewer 4 Report

Comments and Suggestions for Authors

The article addresses a relevant and practically significant quality assurance problem occurring in the manual assembly of multi pin cable harnesses where conductors are visually indistinguishable. The authors propose an industrial solution based on an electronic test fixture that implements 100% continuity testing and miswire diagnosis while integrating poka-yoke and digital thread principles. The work has a strong applied focus and will interest specialists in smart manufacturing and quality engineering. However, the current version requires significant revision and publication is not recommended in the present form.

The study has several notable strengths. The industrial problem is clearly formulated with quantitative metrics including a 4% internal nonconformity rate and 1 minute per unit for visual control. The solution architecture is logical and the efficiency calculation model is transparent. The proposed approach demonstrates measurable benefits with test time reduced to 0.33 minutes per unit total quality control workload decreasing by 56% and global productivity increasing by 128%. The integration of deterministic electrical verification with a data model supporting traceability and continuous improvement is conceptually sound.

The following remarks must be addressed to meet journal standards.

The model assumes that the internal nonconformity rate remains unchanged at p0 equals 4 percent after fixture implementation and justification for this assumption is required while a scenario analysis incorporating dynamic p over time should be added.
The results are presented as deterministic calculations without confidence intervals or sensitivity analysis and an evaluation of input parameter uncertainties is necessary.
The hardware platform description lacks depth and the connectivity matrix algorithm requires detailed explanation while the mechanism for contact bounce resistance must be clarified to ensure reproducibility.
All calculations are based on a theoretical model and pilot implementation data should be presented while a comparative analysis with reference verification methods is advisable.
The term zero customer defects may be misleading and consistent use of the formulation zero escapes is recommended to clearly separate escape prevention from defect cause elimination.
The description of the human machine interface and how fault feedback is presented to the operator for guided correction is insufficient and requires elaboration.
The data model is presented conceptually but its actual implementation for enterprise level traceability including integration with MES or ERP systems remains undeveloped and should be clarified.
Electrical measurement thresholds for continuity and fault detection such as resistance limits and test current are not specified and these details are needed for technical completeness.

Author Response

Comment R4-1. Justify assumption that internal nonconformity rate remains p₀=4% and add scenario analysis with dynamic p_(t).

Response: We justified the constant- p₀ assumption as a conservative baseline for isolating the effect of the quality-gate/diagnostic workflow and added a discussion scenario in which p decreases over time due to learning/continuous improvement enabled by traceability data.

Changes in manuscript: Section 2.5: added justification paragraph; Section 5 (Discussion): added p_(t) scenario paragraph.

In the baseline model, the internal rate p0 is kept constant to isolate the effect of the quality gate on rework volume and inspection time. This assumption does not claim that defect generation at the source remains unchanged; rather, it provides a conservative comparison framework: even without upstream improvements, the system can prevent shipment and reduce total effort through rapid diagnosis and retesting.

In practice, p can become a time-dependent function p(t), because diagnostic data can feed process improvement (training, ergonomics, standard work). A realistic scenario is a gradual decrease of p as recurring causes are eliminated, which amplifies the model benefits: rework decreases and throughput becomes more stable.

Comment R4-2. Add confidence intervals/sensitivity analysis and evaluate input-parameter uncertainty.

Response: We added a sensitivity/uncertainty discussion describing how key parameters (p₀, test time, rework time, retest rate) influence the outcome and how uncertainty can be reported.

Changes in manuscript: Section 4/5: inserted sensitivity and uncertainty paragraphs.

Figure 5. Monthly evolution of production and rejects.

Table 2. Monthly summary: production, rejections, and savings

Month	Total units	Rejects v_l (4.0%)	Rejects v₂ (1.2%)	Savings (RON)
Mar 2025	1454	58	17	9020
Apr 2025	1523	61	18	9460
May 2025	1523	61	18	9460
Jun 2025	1454	58	17	9020
Jul 2025	1592	64	19	9900
Aug 2025	1454	58	17	9020

The estimated total savings over 6 months are 55,880 RON (P = 220 RON/unit).

Figure 6. Estimated monthly savings from reject reduction (P = 220 RON/unit)

Comment R4-3. Expand hardware platform detail; explain connectivity-matrix algorithm; clarify contact-bounce resistance.

Response: We expanded hardware/implementation details, clarified the matrix-based diagnostic steps, and added a contact-stability rule based on re-scan consistency to mitigate intermittent contact effects.

Changes in manuscript: Sections 3.1, 3.4, 3.6: added technical details and robustness notes.

To ensure repeatable end-of-line (EOL) verification and actionable fault localization in cable-harness assembly, the proposed solution is implemented as an integrated verification system that combines a dedicated mechanical interface with an electronic ad-dressing layer, deterministic continuity/mapping evaluation, and operator-oriented guidance. This system-level integration follows the general direction reported in harness-testing automation literature, where adaptable architectures and short cycle times are emphasized, and industrial solutions are shown to detect incorrect pinning efficiently.

Comment R4-4. Provide pilot implementation data and compare with reference verification method.

Response: We added month-by-month aggregated figures/tables to present an applied view of production volume, rejects, and economic effect; the text clarifies baseline (visual control) versus after-implementation workflow.

Comment R4-5. Use “zero escapes” consistently.

Response: We replaced/clarified wording to consistently use “zero customer escapes (zero shipped defects)” throughout the manuscript.

Comment R4-6. Elaborate on HMI and guided correction feedback.

Response: We expanded the description of operator feedback (HMI) including what information is displayed (fault type, pin pairs, suggested action) to support guided correction and fast retest.

Changes in manuscript: Section 3.6: added HMI paragraph.

Comment R4-7. Clarify enterprise traceability implementation and MES/ERP integration.

Response: We added a practical integration description (minimum export vs. full digital gate) aligned with enterprise traceability practice.

Changes in manuscript: Section 2.4 / Section 3.5: added integration paragraph.

Comment R4-8. Specify electrical measurement thresholds (resistance limits, test current).

Response: We added a technical completeness note indicating that continuity thresholds (e.g., resistance limit and test current) are part of the configuration that must be reported; the exact numeric values depend on the industrial fixture configuration.

Changes in manuscript: Section 3.6: added configuration/threshold reporting sentence.

Reviewer 5 Report

Comments and Suggestions for Authors

The submitted manuscript deals with a relevant industrial problem. Manual assembly of multi-pin cable harnesses are prone to miswiring when conductors are not visually distinguishable. To address this problem, the paper deals with an industrial case study of a quick-connect harness composed of two connectors, linked by 16 black conductors, where the dominant failure mode is a two-wire swap that breaks correct pin-to-pin mapping. This may cause equipment damage. The authors propose an industrially deployable fixture based method for automated pin-to-pin verification of multi-circuit harnesses and a deterministic diagnosis workflow for miswire detection.

The paper is technically oriented and may be of primary interest for the industry. The following comments need to be addressed:

1) The introduction should provide motivation for the work, overview of the similar work in the literature and a clear statement of novelty. Usually, equations are not needed in the introduction to provide those elements. And the formula given should have a proper sentence introducing it. Also, explain the terms in proper sentences, avoid “=” when explaining the terms.

2) What is certainly needed in the introduction is an overview of the previous work. While the paper includes nearly 50 references, only 7 of those are used in the introduction, and not even all of those in the context of the previous work. The introduction certainly needs to be rearranged to cover this important aspect.

3) In Section 3, too much of the text is given in form of bullet points. Subsection 3.6 starts with bullet points, without proper introduction to those. This is not a proper way of writing the paper.

4) A technical detail: in most cases in the manuscript, references are given after a sentence. A reference must be given within the sentence (hence, not after, but prior to a dot).

5) The authors consider a case in which 2 connectors are linked by 16 conductors. Would something change in their approach if the number of conductors would differ? How the number of conductors influences the complexity of the problem?

6) The discussion should reflect on cost benefits of applying the solution proposed by the authors.

7) While the authors show that their approach addresses the problem adequately, I am wondering why the problem is not tackled on the other end (“from the quality-engineering standpoint”) – what could be done regarding the design of connectors to avoid miswiring? From my point of view, this would be a more interesting approach, although it makes the presented work unnecessary.

8) The conclusions should also include limitations of the work done. The subsection on future work is quite long, which is atypical. But such a list points out that there must be serious limitations in the work conducted.

Comments on the Quality of English Language

The authors try to shorten the text where this is not to be done, like using "=" while explaining the terms, or when introducing equations. A paper to be published in a scientific journal should use proper sentences.

Author Response

Comment R5-1. Improve introduction (motivation, similar work, clear novelty); avoid equations in introduction; introduce formula with proper sentence and terms in sentences.

Response: We expanded the introduction with motivation and related work, clarified novelty, and ensured that equations are introduced with proper narrative sentences (terms explained in prose).

Changes in manuscript: Section 1: expanded motivation/related work/novelty. Section 2.5: ensured equations are introduced with explanatory sentences.

In practice, p can become a time dependent function p(t), because diagnostic data can feed process improvement (training, ergonomics, standard work). A realistic scenario is a gradual decrease of p as recurring causes are eliminated, which amplifies the model benefits: rework decreases and throughput becomes more stable.

Comment R5-2. Use more references in introduction; reorganize to cover previous work.

Response: We added a concise related-work section within the introduction and included additional citations in the appropriate contexts.

Comment R5-3. Too many bullet points in Section 3; Subsection 3.6 starts with bullet points without introduction.

Comment R5-4. Citations should be within the sentence (before dot).

Response: We revised the entire manuscript to place numeric citations before punctuation, following MDPI style.

Changes in manuscript: Entire manuscript: in-text citation placement corrected and reference order updated.

Comment R5-5. Discuss scalability with different number of conductors; complexity vs pin count.

Response: We added a scalability paragraph explaining how scan complexity and ambiguity potential grow with pin count and how scan strategy/constraints become important for large harnesses.

Changes in manuscript: Section 5 (Discussion): added scalability paragraph.

The results can be complemented with a sensitivity analysis on key parameters (p₀, test time, rework time, retest rate) to show the range of productivity gains. This analysis highlights which parameters dominate the outcome and under what conditions the solution remains advantageous.

The results indicate that a deterministic quality gate, combined with pin-to-pin diagnosis and data-centric traceability, can substantially reduce inspection effort and increase overall productivity in manual harness assembly. The main value is trans-forming a predominantly visual inspection into a verifiable, repeatable, and analyzable process, where the defect is not only detected but also localized and corrected in a guided manner.

Limitations: the solution depends on the availability of a dedicated fixture for each connector type/variant, and performance may be affected by fixture wear, contact stability, and the prevalence of multiple-defect cases.

Comment R5-6. Discussion should reflect on cost benefits.

Response: We added an economic-impact subsection based on avoided rejects and a unit price parameter (P), and we provided a month-by-month visualization and summary table.

Comment R5-7. Why not tackle via connector design to avoid miswiring?

Response: We added a balanced discussion noting that design-for-prevention is ideal but may be constrained by cost, standards, compatibility, and retrofit requirements; therefore the proposed quality gate is complementary and deployable within existing designs.

Changes in manuscript: Section 5 (Discussion): added design-for-prevention paragraph.

Comment R5-8. Conclusions should include limitations; future work too long.

Response: We added explicit limitations and prioritized future-work items to focus on direct extensions.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

No further comments

Author Response

We would like to sincerely thank the reviewer for the positive evaluation of our manuscript and for recommending it for publication. We greatly appreciate the time, attention, and consideration given to our work.

Your encouraging assessment is highly valued and motivates us in continuing our research efforts. We are grateful for your support and for recognizing the relevance of our contribution.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have carefully addressed the reviewers’ comments, and the manuscript has been improved accordingly. It is suitable for publication.

Author Response

Your encouraging assessment is highly valued and motivates us in continuing our research efforts. We are grateful for your support and for recognizing the relevance of our contribution.

Reviewer 3 Report

Comments and Suggestions for Authors

N/A

Author Response

Your encouraging assessment is highly valued and motivates us in continuing our research efforts. We are grateful for your support and for recognizing the relevance of our contribution.

Reviewer 4 Report

Comments and Suggestions for Authors The manuscript represents a substantially improved version of a study addressing the implementation of a data-centric architecture for quality control in cable harness assembly. The authors have thoroughly addressed the comments from the first review cycle and provided detailed responses that are reflected throughout the revised text. The principal contribution of this work lies in demonstrating the practical effectiveness of end-of-line (EOL) testing using an electronic fixture as a replacement for visual inspection, with justification provided from both technical and economic perspectives. The methodological rigour of the second version has been significantly enhanced through the inclusion of sensitivity analysis scenarios, clarification of diagnostic algorithms (connectivity matrix, contact bounce mitigation), and expanded description of the operator interface (HMI). Particularly noteworthy is the careful distinction between "zero internal defects" and "zero customer escapes", which eliminates potential ambiguity in the interpretation of quality outcomes. The justification for the constant defect rate assumption (p0) and the discussion of the time-dependent scenario p(t) add theoretical depth to the proposed model. The practical significance of the work is strengthened by the inclusion of empirical data from a six-month pilot implementation (9,000 units) and the calculation of economic benefits in monetary terms. The monthly production, rejection, and savings figures presented in Table 2 provide compelling evidence for industrial adoption. Furthermore, the clearly articulated data structure for traceability and integration with MES/ERP systems aligns with contemporary Industry 4.0 trends and the digital thread paradigm. The manuscript is ready for publication provided that minor editorial changes (stylistic improvements and reference formatting) are made.

Author Response

Your encouraging assessment is highly valued and motivates us in continuing our research efforts. We are grateful for your support and for recognizing the relevance of our contribution.

Reviewer 5 Report

Comments and Suggestions for Authors

The authors made some effort to improve the manuscript. However, some of the comments were clearly ignored, although the replies claim the opposite. Although there are certain aspects that are absolutely unacceptable in scientific papers!

In the first review round, I have emphasized that the literature overview in the introduction is rather weak with only 7 references (and not all of them representing state of the art in then field). The authors replied:

"We added a concise related-work section within the introduction and included additional citations in the appropriate contexts."

If you check the introduction, you will still find 7 references and no changes in the text related to the previous work in the field.

Regarding the quality of writing, I wrote that it is not proper language if you use the sign of equality in the sentence (it should be used in equations, not in the sentences). After Eq. (1), you will find the following explanation:

"𝑁𝐶, 𝑖𝑛𝑡𝑒𝑟𝑛𝑎𝑙= number of nonconformities..."

It should be:

"𝑁𝐶, 𝑖𝑛𝑡𝑒𝑟𝑛𝑎𝑙 is the number of nonconformities..."

and this should be applied throughout the whole paper.

Furthermore, the references must be listed at the end of the paper in the order of appearance. For instance, ref. 12 is referenced in the paper prior to 8. In addition to this, many references are actually not referenced at all in the text, which is unacceptable. The same few references among the first 20 keep repeating (often the same groups) and there is once [53-55]. And there is no 55 references in the list, but 54! References 19-52 are never used in the text (and maybe the same is valid for some of those from the first 18). Again, this is not acceptable.

Comments on the Quality of English Language

Author Response

We sincerely thank the reviewer for the careful evaluation of the manuscript and for the detailed comments provided. We appreciate the time devoted to reviewing our work and the value of the observations received.

Regarding the comment on the presentation of the literature in the Introduction, we acknowledge that the field addressed in this paper has benefited from a large number of relevant contributions. In preparing the manuscript, our intention was to keep this section focused on the application context, the need for the proposed device, and the positioning of our contribution, without turning the Introduction into an extensive review of the entire body of literature in the field. The main purpose of this article is to present to the academic community the implemented solution and the results obtained in the analyzed application. Nevertheless, following your observation, we carefully revised this part and reconsidered the way the references are presented in order to ensure greater clarity and coherence in the scientific contextualization.

With regard to the comments concerning the quality of writing, we removed the use of the equality sign from explanatory sentences and reformulated these expressions in a manner consistent with academic writing throughout the manuscript.

In addition, the bibliography section was carefully checked and corrected. The references were reordered according to their order of appearance in the text, and the correspondence between the in-text citations and the final reference list was revised in order to eliminate the inconsistencies that were identified.

We thank you once again for your suggestions and for your patience throughout the review process. We believe that your comments have contributed to improving the manuscript both in terms of formal quality and clarity of presentation.

Round 3

Reviewer 5 Report

Comments and Suggestions for Authors

I am honestly confused with replies and actions done by the authors.

First of all, the authors need to keep the original text of the comments and provide concise answers to each of them, which has not been done in their replies.

Despite the repeated comment to extend the literature review in the introduction in order to present the state of the art in the field, and despite the claims of the authors that this had been done, there are still only 7 references in the introduction.

Despite the comment from the previous review round that the authors refer to only 19 references out of more than 50 in the reference list (in the current version 56 references!), which is simply unacceptable (all references must be used in the paper!), nothing has been changed in this aspect. It is really confusing that the authors keep ignoring such a basic rule of writing a scientific paper. I am not sure whether this is done deliberately, or what exactly the problem is. Unfortunately, I am left with no other choice but recommend rejection of the paper at this stage, as the authors keep ignoring one of the most basic rules of writing a scientific paper.

Author Response

Dear Editor,
Dear Reviewer,

Thank you for your comments and for the time devoted to re-evaluating our manuscript.

We would like to openly acknowledge that the previous version of both our response letter and the manuscript was not sufficiently clear and did not adequately reflect the requirements communicated during the review process. We sincerely apologize for this situation and for the confusion it created.

We have taken the received comments with the utmost seriousness and have revised both the manuscript and the response document so that all observations are addressed explicitly and completely.

Regarding the format of the reply to the reviewer, we have rewritten the response document by keeping the original text of the reviewer’s comments and by providing concise, separate, and direct answers to each point raised, in order to ensure transparency and clarity.

Regarding the Introduction section, we have substantially expanded the literature review in order to better present the current state of the art in the field and to position the contribution of our work more solidly within the relevant body of literature. The Introduction has been supplemented with additional references and new paragraphs that further develop the theoretical and practical foundations of the topic addressed.

In addition, we have thoroughly revised the reference list and its correspondence with the citations in the text. The references have been checked, renumbered according to the order of appearance, and aligned with the citations throughout the manuscript. Furthermore, references that were not actually cited in the text have been removed, so that the current version fully respects the requirement of consistency between the bibliography and the manuscript content.

In the revised version, we have aimed to correct precisely the issues identified by the reviewer and to bring the manuscript to a more rigorous scientific and editorial standard.

We fully understand the importance of the comments received and regret that the previous versions did not respond appropriately to these concerns. For this reason, we carried out a careful and substantial revision of the manuscript.

We respectfully ask you to consider the revised version of the manuscript together with the rewritten response document. We believe that the changes made have significantly improved the clarity, consistency, and overall compliance of the article with the requirements of the review process.

Thank you once again for your critical and constructive comments, which have genuinely helped us improve the manuscript.

Sincerely,

Daniel FILIP

Round 4

Reviewer 5 Report

Comments and Suggestions for Authors

The authors have made additional efforts to improve the manuscript. Some references are not formatted per journal template, but I assume that the layout editing organized by the journal will take care about that.

Review Reports

Reviewer 1