Business Rules - Trekking and Mountaineering

This document lists the fundamental rules of the trekking/mountaineering domain, each identified by a unique BR-NNN code. Every rule is technology-independent and describes an invariant constraint on planning, safety, navigation and the management of a hike.

> Informational note: These rules are for educational and domain-modeling purposes. Mountain safety information does not replace specialized training or the judgment of a professional mountain guide.

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BR-001 - Mandatory planning before departure

Code: BR-001 Name: Every hike must have a validated march schedule before starting Description: An Itinerary cannot transition to the IN_PROGRESS state without a march schedule listing departure, intermediate stages with elevation and estimated time (Naismith's rule), total elevation gain/loss (D+/D–) and a weather window. Planning includes verifying the CAI difficulty grade (T/E/EE/EEA) against the hiker's experience. Motivation: Prevent unassessed starts on terrain beyond capability; enable the calculation of a safe return window. Priority: HIGH Actors: Hiker, Mountain Guide Violation: The hike stays in PLANNED state until the schedule is complete. Traceability: Naismith's rule; CAI difficulty scale; plan-hike.md.

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BR-002 - Avalanche bulletin check in winter conditions

Code: BR-002 Name: With snow cover present the EAWS avalanche bulletin must be consulted and recorded Description: For any hike on snow-covered terrain, planning must include the EAWS avalanche danger level (1–5 scale) for the area and elevation involved. From level 4 (High) outings on steep slopes are discouraged; at level 5 (Very high) the hike is not started. Motivation: Avalanche release is the primary cause of fatal accidents in winter mountaineering; risk assessment is essential. Priority: CRITICAL Actors: Hiker, Mountain Guide, Mountain Rescue Traceability: EAWS 5 levels; AINEVA; BR-001.

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BR-003 - Equipment matched to the route grade

Code: BR-003 Name: EEA sections require compliant belay equipment Description: A Trail or Stage classified EEA (equipped, via-ferrata type) requires the HikingEquipment to include a via-ferrata set compliant with the EN 958 standard (Y lanyard with energy absorber, helmet, harness). Progression on equipped sections without an absorber is forbidden by the model. Motivation: In a fall on a via ferrata, the energy absorber keeps the peak force below the injury threshold (6 kN); its absence makes the fall potentially fatal. Priority: CRITICAL Actors: Hiker, Mountain Guide Traceability: EN 958; CAI difficulty scale (EEA); BR-001.

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BR-004 - Return margin within the daylight window

Code: BR-004 Name: The estimated return time must precede sunset with a safety margin Description: The march schedule must ensure that the planned ReturnCompleted event occurs with at least 1 hour of remaining daylight. If the Naismith calculation plus breaks exceeds this threshold, the itinerary must be shortened or departure brought forward. Motivation: Progression in the dark dramatically increases the risk of getting lost and falling, especially on EE/EEA terrain. Priority: HIGH Actors: Hiker, Mountain Guide Traceability: Naismith's rule; BR-001; plan-hike.md.

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Code: BR-005 Name: Navigation must have at least one backup method to GPS Description: Every hike on EE terrain or above must rely on a topographic map + compass as a backup to the GPS device, applying the local magnetic declination. In fog (visibility < 1 km) navigation relies on instruments, not sight. Motivation: Battery drain or GPS failure must not leave the hiker without orientation capability. Priority: HIGH Actors: Hiker, Mountain Guide Traceability: Magnetic declination; WGS84; handle-weather-event.md.

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BR-006 - Position traceability in an emergency

Code: BR-006 Name: A rescue request must carry WGS84 coordinates, elevation and a description Description: The SOSSent event must include the position in decimal WGS84 coordinates (lat/lon), approximate elevation, a description of the injury and local weather conditions, addressed to the single emergency number 112 (or 118 for medical). The alpine signaling triangle (3 signals/minute) is the optical/acoustic fallback when there is no coverage. Motivation: Rescue services can locate and reach the casualty only with a precise position; an SOS without coordinates delays rescue. Priority: CRITICAL Actors: Hiker, Mountain Rescue (CNSAS) Traceability: CNSAS; single emergency number 112; alpine signaling triangle; BR-005.

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BR-007 - Reporting of trail conditions

Code: BR-007 Name: An impassable or closed trail must be reported and propagated Description: When a hiker or hut keeper detects an interrupted Trail (landslide, collapsed bridge, off-season snow), they emit TrailConditionReported; the relevant CAI section may close the trail (TrailClosed) and update the registry. Planned itineraries including that trail must be recomputed. Motivation: Prevent other hikers from facing dangerous sections not yet updated in maps. Priority: MEDIUM Actors: Hiker, Hut Keeper, Mountain Rescue Traceability: CAI trail network; trail registry; report-trail-condition.md.

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BR-008 - Mandatory hut booking in high season

Code: BR-008 Name: Overnight stays in a hut in high season require a confirmed booking Description: A multi-day Itinerary planning a stop at a MountainHut must have a confirmed booking for each night in high season or in adverse weather. The hut capacity (beds) is a constraint limiting the number of hikers accommodated. Motivation: Avoid finding the hut full at altitude as evening falls, a potentially dangerous situation. Priority: MEDIUM Actors: Hiker, Hut Keeper Traceability: CAI hut; bed capacity; plan-hike.md.

Knowledge Domain Database - Trekking