{"actors":["Crane reliability engineer","Crane operator","Maintenance planner","Lifting-equipment safety officer","Strain and motion sensor technician"],"affected_objective":"Schedule inspection or retirement of an overhead-crane hoist rope before decision-relevant fatigue damage is missed, while avoiding unnecessary removal based on coarse usage categories.","arm":"COMMON_P1","authority_safety":{"authorized_first_step":"Run the hybrid model in retrospective, non-controlling shadow mode on one crane's existing sensor and maintenance records; it may produce comparison reports but may not alter operating limits, inspection intervals, or replacement dates.","decision_authority":"The designated lifting-equipment safety officer retains authority over inspection, derating, and retirement decisions, informed by the responsible reliability engineer and existing approved procedures.","excluded_actions":["Automatically extend an inspection interval or service-life limit","Suppress an existing overload alarm or mandatory inspection","Use inferred events as proof that an undocumented lift occurred","Change crane controls, rated capacity, or operator instructions during the first evidence step"],"halt_rollback":"Stop the evaluation if timestamps cannot be reconciled, sensor saturation obscures overloads, or the model would classify a known inspection-triggering event as ordinary flow; retain the current approved maintenance model and discard the shadow model's outputs from operational decisions."},"baseline":"Estimate rope usage from operating hours and aggregate load summaries, apply a continuous fatigue-accumulation calculation to the averaged load history, and separately handle overload alarms as isolated exceptions under fixed inspection rules.","candidate_id":"discrete_continuous_model_selection__engineering_design__COMMON_P1","causal_chain":["A hoist rope experiences gradual fatigue accumulation during ordinary lifting, but overloads, shock loads, emergency stops, reeving changes, and rope replacement create discrete changes in condition or model regime.","A continuous average-load representation can smooth away short events whose sequence or peak character changes an inspection decision.","A purely discrete usage-class model can place similar lifts into different bins and discard within-lift load, duration, and temperature variation.","The intervention represents within-mode fatigue accumulation continuously while preserving defined events and configuration changes as timestamped transitions.","Sampling cadence and event boundaries are selected against the shortest transition that the inspection decision must distinguish, subject to sensor capability.","Retrospective transition validation compares hybrid-model outputs with raw traces, operator logs, alarms, and inspection findings.","If the hybrid representation reduces representation-caused decision disagreements without hiding known events, the safety officer receives a more traceable basis for inspection review; otherwise the baseline remains in force."],"cell_id":"discrete_continuous_model_selection__engineering_design","consequence":"Short, consequential load transitions may disappear into averages, while coarse duty classes may create arbitrary maintenance cliffs; either error can distort which rope histories receive prompt engineering review.","diversity_from_prior_proposals":"No prior proposals were inspected under runtime isolation; this candidate is internally differentiated by focusing on hybrid representation of fatigue flow and discrete load-path events in crane-rope maintenance.","experiment_id":"eoa_inverse_innovation_exp13_second_slot_policy60_20260806","intervention":"Create a shadow-mode hybrid hoist-rope history model. Within each declared operating mode, integrate fatigue-relevant load exposure from time-resolved tension and motion measurements. Record overloads, shock loads, emergency stops, reeving changes, inspections, and rope replacement as discrete events with explicit start, end, merge, and reset rules. Select sampling cadence from the fastest decision-relevant load transition the installed sensors can resolve. For each inspection review, show the continuous accumulation trace, preserved events, uncertain boundary cases, and the maintenance decision produced by the baseline and hybrid representations.","mechanism_mapping":[{"counterfactual_removal":"Without the hybrid model, gradual exposure and discrete shocks remain in separate records with no explicit rule for how events alter subsequent accumulation.","mechanism_slug":"hybrid_discrete_continuous_model","role":"Combines continuous fatigue accumulation within operating modes with discrete shocks, configuration changes, inspections, and replacement resets."},{"counterfactual_removal":"Without an explicit cadence choice, short shock events can fall between observations even if the conceptual model includes them.","mechanism_slug":"sampling_interval_choice","role":"Sets observation cadence and timestamp precision to resolve decision-relevant load transitions within sensor limits."},{"counterfactual_removal":"Without the audit, apparent agreement may conceal missed events, false event splitting, or unstable boundary classifications.","mechanism_slug":"transition_resolution_audit","role":"Tests event detection and continuous interpolation against raw traces, logs, alarms, inspection records, and boundary cases."},{"counterfactual_removal":"Without discrete event records, overloads and configuration changes are smoothed into ordinary exposure and cannot reliably change model mode or reset state.","mechanism_slug":"discrete_event_model","role":"Represents shocks and engineering configuration changes as identifiable state-changing occurrences."}],"nearest_rivals":["Rainflow cycle counting with a cumulative fatigue rule: it summarizes load cycles but need not preserve maintenance-relevant event identities or explicit mode-switch rules.","A standalone overload-threshold alarm: it triggers after a threshold crossing but does not decide how continuous exposure and discrete events should jointly be represented.","A duty-class or workflow-stage maintenance scheme: it supplies legible categories and responsibilities but can introduce boundary cliffs and discard within-class variation.","A higher-frequency continuous condition-monitoring dashboard: it increases temporal detail but can still smooth, interpolate across, or fail to type discrete configuration changes."],"negative_tests":{"intervention_falsifier":"On the bounded replay, reject the intervention if the hybrid model misses any baseline-recognized mandatory-review event, creates event boundaries that cannot be reproduced from the specified data, or fails to change any representation-caused disagreement while adding unresolved classifications.","problem_falsifier":"The inferred problem is weakened if all inspection-relevant transitions are already explicitly preserved and linked to continuous exposure at adequate resolution, or if replayed decisions are invariant across continuous, discrete, and hybrid representations.","risks":["Sensor saturation or clock drift can manufacture, merge, or misorder events.","Event-boundary rules may overfit the replayed crane and fail under another duty profile.","A detailed accumulation trace may imply precision unsupported by material-condition uncertainty.","Operators or reviewers may treat a shadow estimate as permission to defer mandatory action.","Additional event labels may increase review burden without changing decisions."],"strongest_counterevidence":"Existing approved fatigue calculations, alarm records, and inspection rules may already preserve every transition that affects maintenance decisions, making representation change unnecessary."},"next_evidence_step":"Using only existing records from one crane, replay a bounded set of 20 consecutive instrumented shifts containing at least one logged alarm or inspection-triggering event. Before examining outcomes, specify event boundaries, continuity assumptions, sampling cadence, missing-data handling, and decision comparison criteria. Have two blinded engineering reviewers compare baseline and hybrid inspection-review classifications against raw traces and logs; report missed events, false events, boundary disagreements, unresolved cases, and whether either representation would alter a review decision. Do not operationalize the model from this step.","observable_state":"For each lift, timestamped rope tension, hook motion, hoist speed, motor current, alarm status, emergency-stop status, crane configuration, and sensor-quality flags are available alongside operator logs, inspection findings, and rope installation or replacement records.","prior_art_status":"UNSEARCHED","problem":"The maintenance model for an overhead-crane hoist rope treats fatigue as smooth accumulation from aggregate load history while treating overloads and configuration changes in separate logs. This granularity can hide short load shocks, leave ambiguous when several sensor excursions constitute one event, and create inconsistent treatment of gradual exposure near fixed duty-class boundaries.","proposal_index":1,"remaining_contrastive_claim":"For hoist-rope inspection review, an explicitly validated hybrid representation can preserve continuous fatigue exposure and discrete state-changing events in one decision record in a way that a smoothed accumulation model, an overload trigger, or a duty-class state scheme does not by itself.","revision_record":{"claim_changes":["Initial version; no prior claim was revised."],"conceptual_changes":["Initial version maps mixed rope-fatigue dynamics to a hybrid step-flow representation."],"evidence_changes":["No evidence is claimed; a bounded retrospective replay is specified."],"operational_changes":["Initial version restricts use to non-controlling shadow mode with retained human safety authority."],"parent_version":null,"progress_targets_addressed":["Concrete decision task and actors","Observable mixed change signature","False-smoothness and false-discreteness costs","Explicit hybrid boundaries and sampling cadence","Transition validation and falsifiers","Authority, safeguards, rollback, and bounded evidence step"]},"schema_version":1,"structural_mapping":[{"archetype_element":"Decision Need","domain_realization":"Determine which rope histories require inspection, engineering review, derating, or retirement under existing safety procedures."},{"archetype_element":"Process Change Signature","domain_realization":"Fatigue exposure accumulates over time within a lifting mode, while shocks, stops, reeving changes, inspections, and replacement occur as discrete transitions."},{"archetype_element":"Cost of False Smoothness","domain_realization":"Averaging can erase a short overload, shock sequence, or mode change that should remain visible during inspection review."},{"archetype_element":"Cost of False Discreteness","domain_realization":"Duty classes or load bins can separate nearly identical histories and conceal consequential variation within a bin."},{"archetype_element":"Granularity Choice","domain_realization":"Use continuous time-resolved accumulation inside declared modes and discrete records only for events that can change condition, accountability, or model parameters."},{"archetype_element":"Step Boundary","domain_realization":"Define when a shock or overload starts and ends, how adjacent excursions merge, when a configuration change takes effect, and when replacement resets the rope history."},{"archetype_element":"Continuity Assumption","domain_realization":"Interpolate load only across intervals with valid sensor data and no logged stop, alarm, configuration change, or gap exceeding the predeclared limit."},{"archetype_element":"Measurement Resolution","domain_realization":"Choose sampling cadence and timestamp tolerance sufficient to distinguish the shortest load transition relevant to inspection review, without claiming resolution beyond sensor bandwidth."},{"archetype_element":"Hybrid Boundary Rule","domain_realization":"A qualifying event closes the current continuous segment, records the transition, and opens a new segment with retained or reset state according to the specified event type."},{"archetype_element":"Transition Validation","domain_realization":"Compare modeled transitions with raw sensor traces, alarms, operator logs, configuration records, and inspection findings."},{"archetype_element":"Approximation Error Check","domain_realization":"Compare inspection-review classifications under the baseline and hybrid representations, emphasizing missed known events, false events, and unstable boundary cases."}],"title":"Hybrid Event–Exposure Ledger for Crane Hoist-Rope Inspection","version":0}