Based on the context of workplace accidents in Romania, as well as European and global perspectives, the development of this work was guided by several research questions: Q1. How can Bird’s Pyramid and the 5M Method be applied to effectively manage workplace health and safety (WHS) risks? Q2. How does the Weighted Composite Score (WCS) algorithm improve upon and compare with the classic risk assessment model? Q3. What benefits does the Composite WCS model provide over the Classic model in terms of risk identification and mitigation? Q4. What challenges or obstacles are associated with implementing these risk assessment methods in industrial environments?
2.1. Workplace Accident in Romania: European and Global Perspective
Workplace accidents represent one of the most serious challenges for the labor market, directly affecting workers’ health and lives, as well as the productivity and sustainability of organizations [
45]. In this context, Romania, together with other European countries and the international community, acknowledges the importance of implementing effective and well-structured occupational health and safety management systems (OHSMSs), such as the ISO 45001 standard.
Table 2 provides a comparative overview of workplace accidents and the adoption of occupational health and safety standards, based on the most recent data available.
According to official data from the Territorial Labor Inspectorate from Romania and the annual report of the Ministry of Labor and Social Protection, Romania recorded 4862 workplace accidents in 2023, with a population of 17.943 million people over the age of 18. These figures underscore the urgent need for the implementation of a structured and proactive OHS management system, as prescribed by ISO 45001, which advocates a systematic approach to risk identification and control, alongside active engagement of all personnel in maintaining a safe working environment [
48].
Across most countries, the primary causes of serious accidents remain consistent: inadequate training and education, insufficient or inappropriate protective equipment, and hazardous working conditions [
51]. Higher-level preventive measures are proactive actions aimed at eliminating or reducing hazards at the source, including hazard elimination, substitution with safer alternatives, and workplace design to minimize or remove risks.
Statistical data clearly highlight the necessity of implementing occupational health and safety management systems that operate on proactive, systematic, and integrated principles within organizational processes. The international standard ISO 45001 provides a comprehensive framework for identifying, assessing, and controlling occupational risks, as well as for the active involvement of all personnel in creating and maintaining a safe working environment [
8].
In Romania, the implementation of ISO 45001 is essential for aligning with legislative requirements and reducing workplace incidents. Equally important is the improvement of legal provisions to ensure the systematic reporting not only of severe incidents but also of minor accidents and near misses, which are often underreported. Such comprehensive reporting would enhance prevention strategies and strengthen the effectiveness of occupational health and safety management systems. At the European level, the widespread adoption of this standard supports the strengthening of a shared safety culture, thereby contributing to accident reduction and enhanced economic competitiveness. On a global scale, ISO 45001 is recognized and applied primarily in multinational companies and high-risk sectors, where social responsibility and legal compliance are key [
52].
Romania records statistical patterns comparable to European and global. The apparently lower number and rate of accidents is largely due to national reporting practices, where only severe incidents are systematically reported to the authorities, while minor cases remain at organizational level. Nevertheless, the considerable number of severe accidents and fatalities underlines the need for consistent implementation of ISO 45001 requirements as a key tool for accident prevention and employee protection [
53].
Risk analysis and assessment represent a fundamental component of the OHSMS, aiming to identify hazards, evaluate the risks associated with workplace activities, and implement prevention and protection measures, in accordance with ISO 45001 principles and national legislation, in order to ensure a safe, healthy, and efficient working environment.
OHS Risk Management is a crucial component in the legislative landscape of most countries and for any business. Existing harm reduction methodologies are primarily based on risk methodology, namely, reducing the consequences or the likelihood of harm. The implementation of the ISO 45001 standard involves establishing OHSMS within an organization.
2.2. Managing WHS Risks Based on Bird’s Pyramid and the 5M Method
According to the adapted Bird Pyramid [
54], for every fatal accident there are approximately 30 serious accidents, 300 minor accidents, 30,000 hazardous incidents, and 300,000 near-miss events. This pyramidal structure demonstrates that low-severity events serve as significant indicators of the overall safety level within an organization. Neglecting these early warning signals facilitates the accumulation of risk factors, thereby increasing the likelihood of severe accidents.
The practical relevance of Bird’s Pyramid lies in its value for effective risk management, emphasizing the need for systematic reporting and documentation of all incidents, including those that may appear insignificant, the careful analysis of near-miss events as valuable sources of organizational learning, and the development of a proactive safety culture focused on prevention and continuous improvement.
Thus, Bird’s model [
55] highlights that preventing and controlling minor incidents has a direct impact on reducing the probability of serious accidents, positioning the pyramid as a strategic reference that supports the transition from a reactive to a preventive and systematic approach to workplace safety.
The cause of a workplace incident is defined as the set of practices, factors, and situations that contribute to the occurrence or aggravation of a hazard during operations, affecting equipment, materials, goods, or the working environment, and thereby endangering the health and safety of employees.
In identifying the causes that may lead to a potential risk, the cause-and-effect diagram is used, based on the 5M analysis and the “5 Whys” method.
Table 3 provides an example of hazard identification that may generate risks associated with occupational health and safety, using the Ishikawa diagram. The analysis enables the structuring of hazards according to the five M factors (Man, Machine, Method, Material, Medium) and their correlation with possible consequences and applicable preventive measures.
Table 3 provides a clear overview of the main hazards, potential consequences, and preventive measures associated with each factor analyzed using the 5M method. It facilitates the identification and management of workplace risks and supports the implementation of a proactive safety culture.
Example: Risk analysis of a slip accident in a warehouse.
This structure shows how each 5M category contributes to hazard identification, the assessment of potential consequences, and the determination of preventive measures, exactly as the Ishikawa diagram is applied in OHS.
Based on the hazards identified in
Figure 1, potential consequences are determined, and preventive measures are proposed for each of the five M factors to ensure effective risk management in work activities (
Table 4).
The integration of Bird’s Pyramid and the 5M method as a means to identify workplace hazards supports a proactive safety culture and helps prevent accidents.
2.3. Occupational Risk Assessment: Classical Model
The case study was conducted in a production facility with a mixed industrial profile, encompassing mechanical, electrical, and logistics operations. The facility maintains an average of approximately 150 active employees per day, working in environments with varying degrees of occupational risk. The identified hazards include the operation of industrial machinery, handling of chemical substances, and the use of electrical equipment—each presenting specific potential threats to the safety and health of the workers.
Table 5 presents the occupational safety performance of the production unit over the last five years.
According to the presented data, there is a noticeable reduction in the severity of incidents, reflected by the absence of fatalities after 2021 and the very low number of lost-time accidents (LTAs). At the same time, an increase in the total number of incidents and reported situations, including near misses and risky situations, can be observed. This trend may indicate either a higher exposure of employees to occupational hazards or an improvement in the reporting and monitoring system of safety events.
Occupational risk assessment is a fundamental pillar of OHSMS, and conducting a comparative analysis between the classic methodology—based on the product of Severity × Probability—and a proposed weighted composite algorithm represents a solution for optimizing the assessment process and ensuring compliance with the requirements of the international ISO 45001 standard.
Table 6 presents the classical risk assessment, defining risk classes, their impact, and recommended control measures.
Table 7,
Table 8,
Table 9 and
Table 10 provide a summary of the risk assessment for occupational injuries and illnesses, adaptable to all workplaces within an organization, covering all components of the work system. The assessment was carried out using a standardized grid based on the combination of the severity class of consequences and the probability class of risk occurrence [
56]. In accordance with the requirements of the OHSMS, risks are classified according to their main source: production means (technical execution); work environment; work task, and human factors (the worker). Each category is detailed in the corresponding tables, presenting the identified risk factors, specific manifestations, possible causes, maximum foreseeable consequences, severity class, probability class, and the associated risk level.
Table 7 identifies and evaluates risks generated by the use of technical production means, such as equipment and machinery, within the work process. Mechanical, thermal, electrical, and biological hazards are analyzed, along with their causes, consequences, and associated risk levels.
Table 8 highlights physical and chemical risk factors present in the environment where workers carry out their activities (air currents, ozone, chemical substances). It details their forms of manifestation, causes, consequences, and the assessment of the associated risks.
This section analyzes the risks arising from how work tasks are designed and executed. It includes inappropriate work content, physical and mental overload, and their impact on worker safety.
Table 10 identifies human errors (wrong actions and omissions) as risk factors in the work process. It analyzes inappropriate behaviors, lack of training or attention, and the associated consequences. Additionally,
Table 11 presents a prevention and protection plan specifically targeting the risk of electrocution, including technical and organizational measures aimed at reducing or eliminating this risk, in line with best practices and legal requirements.
Table 11 presents specific technical and organizational measures for preventing the risk of electrocution, both through direct and indirect contact. It includes solutions such as equipment insulation, use of personal protective equipment (PPE), and safe working procedures, especially applicable to activities involving electrical installations.
2.4. New Risk Assessment Structure
We proposed an exploratory conceptual framework—the Weighted Composite Score (WCS)—which integrates not only severity and probability but also operational and organizational dimensions (frequency of exposure, extent of workforce exposed, organizational response capacity, and history data).
The WCS model is presented as an illustration rather than a full validation, emphasizing its potential usefulness and the need for further empirical calibration:
where S—severity (1–10), P—probability (1–10), F—frequency of exposure (0–5, dimensionless ordinal), N—extent of exposure (0–4, dimensionless ordinal), R—response/prevention capacity (−2 to +2, dimensionless ordinal; negative = strong measures, positive = weak measures), and H—incident history (0–5, dimensionless ordinal).
All parameters are expressed on normalized ordinal scales (dimensionless), ensuring mathematical consistency. In this formulation, F, N, R, and H act as influencers that adjust the baseline S × P score.
Table 12 presents the risk assessment based on the proposed composite algorithm, outlining the risk classes, their impacts, and the recommended control measures.
As part of the risk assessment using the composite algorithm, four additional variables were defined beyond the classic model (S × P), in order to more accurately reflect the operational reality of the workplace. These variables are:
1. Frequency of exposure (F) variable reflects recurrence of the risk event, rated. It is rated on a scale from 0 to 5, based on the nature and recurrence of the activity: a value of 5 (Daily) is assigned to activities that occur every day, such as machine operation or repetitive manual handling; a value of 4 (Weekly) corresponds to tasks that happen regularly but not daily—these are recurring, such as weekly logistics operations; a value of 3 (Monthly) applies to periodic tasks, for example, monthly technical maintenance; a value of 2 (Quarterly) is used for occasional activities that take place once every few months; a value of 1 (Rare/Exceptional) represents very rare tasks performed only in special circumstances or emergencies; a value of 0 (None) is used for no accidents have occurred.
The model, while developed for a specific case, can also be applied to similar cases and adapted to the specific characteristics of each context, with numerical results adjusted accordingly.
Example: For the risk of falling objects in the logistics area (e.g., pallet handling), the frequency was rated 4, as these operations are performed on a weekly basis in a continuous flow.
2. Extent of exposure (N) variable indicates workforce potentially. It is assessed on a scale from 0 to 4.
Example: For the risk of electric shock, N was rated as 1 (only technical team).
Note: N could also be embedded into S, since broader exposure increases severity. However, we separate them to explicitly distinguish individual injury severity (S) from workforce exposure extent (N).
3. The Response capacity (R) variable: Revised to cover both protection and prevention. Rated −2 (excellent) to +2 (deficient). Example: Electric shock = −1 due to PPE and procedures.
4. The Incident history (H) variable takes into account past events related to the analyzed risk. It was assessed using accident records, incident reporting forms, and interviews with (OHS) personnel. Incident history is rated on a scale from 0 to 5, based on the severity and frequency of previous events: a value of 0 indicates no reported incidents; 1 corresponds to minor events with negligible consequences; 2 reflects one to two moderate incidents; values between 3 and 5 indicate repeated or severe incidents.
Example: For the risk of falling objects, a minor incident was recorded in the previous year (resulting in a superficial injury), so H was rated as 1.
To illustrate the contrast, we compared results obtained using both the classical and WCS models.
Table 13 presents ranking by WCS, showing differences in prioritization.
The table illustrates how the prioritization of workplace risk factors changes when using the WCS composite index versus the classical method. Differences in ranking reflect the impact of weighting and scoring criteria applied in the WCS approach, highlighting risks that have been re-prioritized.
The highest-scoring risk—crushing or pinching by unstaked products (score 18)—represents a serious and frequent hazard with documented historical incidents. This underscores the urgent need for both technical interventions (such as proper stacking and designated storage areas) and organizational measures (including handling procedures and targeted training). Notably, organizational risks like unplanned operations and omission of safety measures also scored highly, highlighting the vital role of organizational culture and ongoing training in preventing accidents.
This approach enables objective prioritization of risks based on a clear numerical index, easily comparable across different activities or hazard types. Integration of contextual factors, such as the number of exposed individuals or the presence of already implemented mitigation measures, provides a realistic view of the current risk level. Consideration of incident history (H) as a corrective factor directly reflects operational realities and field trends.
This methodology directly aligns with the principles promoted by ISO 45001, which emphasizes a systematic approach to risks and opportunities through a comprehensive, multidimensional risk assessment—not limited to consequences or probability alone. Integration of risks into organizational processes means the composite score offers an operational tool that can be correlated with performance indicators, prevention plans, and occupational safety investments. Continuous improvement is enabled, as data can be periodically updated, allowing for monitoring risk evolution over time and adjusting preventive measures accordingly. Therefore, the use of the composite score is not merely a classification technique but a strategic occupational health and safety management tool, aligned with the requirements and philosophy of ISO 45001, which calls for a holistic and proactive vision of workplace safety.
The analysis results, ranked in descending order by composite score, enabled identification of the most critical risks—such as electrocution or unauthorized operations—and provide a foundation for developing a prevention and protection plan with clear priorities focused on technical, organizational, and educational interventions.
To illustrate the comparative application of the two risk assessment methods, two representative risk types were selected:
Risk 1: Electric shock through direct contact.
Risk 2: Falling objects from height.
- (a)
Assessment Using the Classical Method (S × P)
The classical risk assessment model involves calculating the risk score by multiplying two factors: S = Severity of consequences (scale: 1–minimal, 10–fatal) and P = Probability of occurrence (scale: 1–unlikely, 10–inevitable).
Risk 1: S = 7 (potentially fatal accidents) and P = 1 (strong protection measures) → Risk Score: R = 7 × 1 = 7.
Risk 2: S = 6 (moderate to severe trauma) and P = 2 (partially controlled conditions) → Risk Score: R = 6 × 2 = 12.
- (b)
Assessment Using the WCS
Risk 1: S = 7, P = 1, F = 3, N = 1, R = −1 and H = 2 → Score: (7 × 1) × (1 + 3 + 1 − 1 + 2) = 7 × 6 = 42.
Risk 2: S = 6, P = 2, F = 4, N = 3, R = −1 and H = 1 → Score: (6 × 2) × (1 + 4 + 3 − 1 + 1) = 12 × 8 = 96.
As shown in
Table 14, the composite model provides a much more realistic picture of the risk level by taking into account essential operational factors. The classical model tends to underestimate risks in dynamic industrial environments like the one analyzed.
The application of the composite algorithm contributes to the transition from a reactive to a proactive approach, allowing continuous adjustment of prevention plans based on real data and the dynamics of risks in the field.
To assess the robustness and relevance of the proposed WCS model, a sensitivity analysis was carried out by varying each component parameter (S–severity, P–probability, F–exposure frequency, N–number of exposed persons, R–response capacity, and H–incident history) by ±1 unit.
We select a risk (ex: Falling objects from a height). The results of this analysis are presented in
Table 15, which shows how the final WCS changes depending on parameter variations. It can be observed that the model is most sensitive to probability, followed by severity, while the operational variables (F, N, R, and H) influence the score to a moderate extent. This approach confirms that the proposed method allows the identification of critical factors and the proper prioritization of risks in the context of OHSMS and ISO 45001 principles.
The simplified sensitivity analysis highlights that the Weighted Composite Score (WCS) model reacts differently to variations in its input parameters. The results show that probability is the most influential factor, as a ±1 variation changes the score by ±50%. Severity also has a significant impact (±16.7%), while the operational parameters–exposure frequency (F), number of exposed persons (N), response capacity (R), and incident history (H)–have a more moderate but consistent effect (±12.5%).
This pattern indicates that the model places strong emphasis on the likelihood of occurrence and the potential severity of incidents while still accounting for contextual and organizational factors. Such a structure supports effective risk prioritization in line with OHSMS and ISO 45001 principles, ensuring that critical hazards are identified and addressed first, while operational factors refine the overall risk evaluation.
While some parameters of the WCS model (e.g., Response capacity, Incident history) involve subjective evaluation, the influence of Probability and Severity on the WCS is largely objective and can be applied across different contexts. The approach can be extended by adapting context-specific parameters and incorporating empirical data, allowing the model to support risk prioritization and decision making in various real-world applications.
However, it should still be noted that the simplified sensitivity analysis (
Table 15) shows that Probability and Severity have the strongest impact on the WCS. This analysis is limited to the studied context and may be extended in future research to broader applications.