Overview
UNOCS and alignment to other ontologies
A holistic safety ontology requires a broad knowledge base and specific domain expertise. Using ontology modularization, UNOCS reduces complexity by dividing the ontology into reusable, purpose-driven modules. This approach enables flexible extensions and simplifies development and maintenance. Organization UNOCS reuses DiCon and OCQA as modules to provide the basic terminologies and concepts related to construction execution and inspection planning, respectively. DiCon is a higher-level domain ontology that generalizes construction workflow knowledge with related entities and properties . The DiCon ontology contains basic concepts for describing components related to construction processes. DiCon aligns with existing relevant ontologies that enable the direct integration of heterogeneous systems in the construction domain like ifcOWL and BOT to integrate building information models, organizational descriptions, and schedules. The OCQA is a formal and comprehensive knowledge representation and terminology for representing and planning inspection plans in construction. The descriptions are relevant due to one of the specified use cases in order to inspect safety equipment on site. In addition, the ontology enables the collection of inspection-related data from heterogeneous sources, which improves interoperability and enables networked and project-related planning between project participants.
Core of UNOCS
The Core Ontology Module of UNOCS establishes the fundamental entities and relationships necessary for managing construction safety knowledge. It connects hazards to incidents through the unocs:causes property, illustrating how hazards can lead to incidents, and models the involvement of victims using unocs:hasVictim. To mitigate these risks, hazards are linked to corrective actions (unocs:CorrectiveAction) that reduce the likelihood of incidents. Safety inspections (unocs:SafetyInspection) play a crucial role in verifying that these corrective actions are effectively implemented and compliant with regulations. The Core Module integrates concepts from established ontologies like DiCon and OCQA, enabling comprehensive representation of locations, activities, equipment, agents, and organizations. This integration allows seamless alignment with construction schedules and resource allocations, enhancing the interoperability of safety and construction knowledge. By incorporating these elements, the Core Module ensures adaptability to dynamic construction environments and supports a variety of safety management scenarios. The modular design also promotes flexibility and reuse across projects, ensuring that the ontology can evolve to meet new requirements.
UNOCS - Hazard
The Hazard Representation Module is a critical part of the UNOCS ontology, designed to model and represent various hazards encountered in construction environments. At its core is the unocs:Hazard class, which provides a structured framework to represent hazards and their associated properties, ensuring alignment with safety regulations. Hazards are connected to risks (unocs:Risk) and incidents (unocs:Incident), enabling detailed representation and analysis of safety scenarios. To classify hazards as controlled or uncontrolled, the module incorporates attributes that evaluate risk levels against predefined thresholds (unocs:ResidualRisk). Controlled hazards meet specific requirements (unocs:Requirements) through corrective actions (unocs:CorrectiveAction) that transform non-conformities into conformance, as per ISO standards. The temporal and spatial aspects of hazards are inherited from dicp:Activity, allowing integration with construction schedules and defining the location, agents, and building objects involved. The module also addresses hazard categorization standards, including frameworks like the Energy Wheel, BG BAU, and PAS1192, providing interoperability across various regulatory systems. Specific subclasses, such as unocs:FallFromLadder and unocs:SlipOrTripOnSameLevel, enable detailed management of fall-related hazards. The Hazard Representation Module facilitates comprehensive hazard analysis, supports compliance with safety regulations, and improves construction safety management. Through its structured design, it provides the flexibility to adapt to diverse standards and project-specific requirements.
UNOCS - Mitigation
The Mitigation Module of UNOCS focuses on managing hazards to ensure they are controlled and their residual risks are reduced to acceptable levels. Controlled hazards meet specific requirements (unocs:Requirements) through planned corrective actions (unocs:CorrectiveAction), which eliminate non-conformities as outlined by ISO:45001 standards. This module addresses the inconsistency in terminology across construction safety by providing a unified framework that encompasses terms such as control measures, mitigation measures, and treatment plans. Corrective actions in UNOCS inherit temporal and spatial attributes from dicp:Activity, enabling integration into construction schedules. These actions specify start and end dates, locations, and assigned workers (unocs:Agent) responsible for execution. Additionally, corrective actions involve building objects (e.g., fall protection systems, hole covers) and equipment (e.g., hard hats, sun protection), which are essential for mitigating hazards effectively. The aggregation of all corrective actions forms the unocs:MitigationPlan, which represents a comprehensive set of activities designed to address known hazards on a construction site. This plan ensures that all safety measures are implemented and validated through inspection processes, providing a structured approach to hazard mitigation. By unifying mitigation concepts and integrating them with existing safety standards, the Mitigation Module enhances the ability to manage safety risks systematically and adapt to diverse construction scenarios.
UNOCS - Safety
Relevant entities for safety inspections address various aspects of inspection processes within the construction safety domain. The central entity, unocs:SafetyInspection, inherits from dicp:Activity to incorporate the temporal aspect, required equipment, and the assignment of a responsible worker to complete the task. The purpose of the inspection is to verify the correct implementation of corrective control actions and the associated corrective control entity. Consequently, the inspection must ensure follow-up on the corrective control action.
The inspection is linked to several requirements outlined in regulations, with each requirement defining the necessary characteristics of corrective control entities. However, the actual characteristics of these entities may differ from the specified requirements. A nonconformity arises if the actual characteristics deviate from the requirements, necessitating the initiation of a new corrective action.
