Today, most of the top managers, contractors and workers, who work in construction industry, are aware about the significance of preventing accident.( In fact they know that ignoring safety and health can impose a high penalty on a company -large or small. Also individual accident or injury can mean compensation, time off and lost production and what have seemed to be a minor risk becomes a major liability)(safety at work/compiled by Badrie Abdullah/p.iii). Therefore they know the valuable of occupational safety and health management (OSH), although most of the managers haven’t enough knowledge about OSH. It means that they don’t know what the OSH is and how they must use it. In this report I try to investigate different part of OSH management in addition the need for it.
In current years, construction accident rates have decreased as a result of substantial effort by many parties. Increased pressures from OSHA and owners, and increased cost of accidents raised the contractors’ awareness. In turn, contractors increased safety training and enforcement. These efforts have decline the injury and illness rate from 12.2 in 1993 to 7.9 in 2001.
The recent approach to accident prevention is based on OSHA’s violations approach and focuses on prescribing and enforcing “defenses” that is, physical and procedural barriers that reduce the workers’ exposure to hazards. The violations of the defenses are called “unsafe conditions” and “unsafe behaviors.” (Systems Model of Construction Accident Causation /Panagiotis Mitropoulos1; Tariq S. Abdelhamid2; and Gregory A. Howell3.p.1&2)
Only knowing about the benefits of OSH management isn’t enough, we must be act and apply it. So at first it’s important to understand the necessity of OSH management then definition of OSH management and finally how we can follow its rules to make our workplace safe.
Who are included in the safety value chain?
Maybe, it `s better to ask this question “who should be interested in accident causation and safety system?”
In fact the safety value chain includes students, researchers, technicians, system designers, operators, managers, shareholders, accident investigators and safety inspectors. (Fig.1), all these groups affect to system safety in different time-scale. Educators and researchers play important role in this safety value chain, because educators by teaching safety culture can help students to have awareness before they enter to workplace and they impact on accident prevention in long term.
Short- term Medium-term Long-term
Accident investigators, safety inspectors, and regulators
Organizational/ Managers and company executives
Operational/ Technicians and system designers
Technical/ Engineers and system designers
Research researchers and academics
Fig 1.safety levers and shareholders in the safety value chain
Accident theories based on year:
Multi casual Model
Critical Incident Technique
Combination of Factors Model
Goals Freedom Alertness Theory
Energy Exchange Model
Haddon et al
Hale & Hale
Anderson et al
Fault Tree Analysis II
Hoys & Zimolong
Life Change Unit Model
Hazard Carrier Model
Hoys & Zimolong
Waller & Klein
Multilinear Events Sequencing Model
Systems Safety Analysis
Smillie & Ayoub
Risk Estimation Model
Danger response Model
Hale & Prusse
Incidental Factor Analysis Model
Accident Sequence Model
Quoted in Sanders & McCormick
Corlett & Gilbank
Zabetakis, quoted in Heinrich et al
Stair Step Model
Douglas, quoted in Heinrich et al
Motivation Reward Satisfaction Model
Petersen, quoted in Heinrich et al
Ball, quoted in Heinrich et al
Firenze, quoted in Heinrich et al
Suchman, quoted in Heinrich et al
Updated Domino Model
Bird Jr, quoted in Heinrich et al
Updated Domino Model
Adams, quoted in Heinrich et al
Updated Domino Model II
Weaver, quoted in Heinrich et al
Task Ability Model
Drury & Brill
Kjellen & Hovden
Kjellen & Larsson
Traffic Conflicts Technique
Signals Passed at Danger Decision Tree Model
Taylor, R. K. and Lucas, D.A in ch.8 of Van Der Schaaf , Lucas & Hale
Ergonomic & Behavioral Methods
Human Causation Model
Mager & Pipe
Near Accidents & Incidents
Contributing Factors Model
Sanders & Shaw
Hazard Carrier Model
Hayos & Zimolong
Comprehensive Human Factors Model
View of Workers on Safety Decisions Model
Kriebel, quoted in Cone et al
Federation of Accident Insurance Institution(Finland)Model
Question Tree Model
Hale et al.in Van Der Schaaf, Lucas & Hale
Occurrence Consequence Process Model
Onward Mappings Model based on Resident Pathogens Metaphor
Functional Levels Model
Hurst et al
Attribution Theory Model
Fig.2 Accident theories (Enhancing Occupational Safety and Health, Geofry Taylor, Kellie Easter, Roy Hegney)2004
What is occupational safety and control?
The Occupational Safety and Health management is a management which provides the legislative framework to secure the safety, health and welfare among all workforces and to protect others against risks to safety or health in connection with the activities of persons at work.( Job Seeker Handbook/alaysian Labour Law : Regulation of Employment)
Occupational health and safety is a discipline with a broad scope involving many specialized fields. In its broadest sense, it should aim at:
the promotion and maintenance of the highest degree of physical, mental and social well-being of workers in all occupations;
the prevention among workers of adverse effects on health caused by their working conditions;
The protection of workers in their employment from risks resulting from factors adverse to health;
The placing and maintenance of workers in an occupational environment adapted to physical and mental needs;
The adaptation of work to humans.
In other words, occupational health and safety encompasses the social, mental and physical well-being of workers that is the “whole person”. (Website of International
What is an accident?
It is necessary to define what we mean by the word “accident”, because before anyone can begin to put up any sort of a flight, he must know his enemy. So we must do the same.
An accident is an unplanned event, which could result in injury to persons or in damage to plant and equipment or both. Also accidents are consequent of unplanned (unsafe) acts or unplanned (unsafe) conditions performed or created by people. In fact people cause accidents, by what they do or what they neglect to do and the activity of people, in a factory or any other place of work, are controlled by management. (a safe place of work/D.WB James/p.5&6)
From the linguistic point of view, the word accident is the present participle of the Latin verb accident which means “to happen”, which in turn is derived from ad- + cadere, meaning to fall. The literal meaning of accident is therefore that of a fall or stumble. The derivation from “to fall” is significant, since falling is not something one dose on purpose. If someone falls while walking or while climbing, it is decidedly an unexpected and unwanted event. It is, in other words, what we call an accident: an unforeseen and unplanned event, which leads to some sort of loss or injury.
Other definitions of “accident “, such as they can be found in various dictionaries, concur that an accident is an unforeseen and unplanned event or circumstance that (1) happens unpredictably without discernible human intention or observable cause and (2) leads to loss or injury. Used as an adverb, to say that something happens accidently or happens by accident means that it happens by chance. (Barriers and Accident Prevention/Erik Hollnagel p.3&4/2005)
The need for accident models
It is a truism that we cannot think about something without having the words and concepts to describe it, or without having some frame of reference. The advantage of having a common frame of reference is that communication and understanding become more efficient, because a number of things can be taken for granted. The frame of reference is particularly important in thinking about accidents, because it determines how we view the role of humans. (Barriers and Accident Prevention/Erik Hollnagel p.44&45/2005)
Accident causation models:
Figure 2. Diagram showing the dominate five perceptions of accident causation (Benner 1975).
The single event concept
SINGLE EVENT CONCEPT
What the first opinion of accident causation is the Single Event Concept. This idea concentrates that a single event caused accident. It means that this simple model is the widest
The first perception of accident causation is the single event concept. This concept focuses on the premise that accidents are caused by a single event. This simple model exemplifies the quest for the “cause” of what occurred. The search for a scapegoat and taking care of the scapegoat would solve the problem. This concept is the most widely perceived and least complex. The public and media typically utilize this concept when they ask “what caused the accident?”
The single events concept is limited in its ability to see the accident as a process or sequence of events in time. The factors that may contribute to the accident are not identified or pursued due to the fact that the “real” cause is obvious and visible. Causes that may underline human behavior are rarely determined.
Current applications are primarily apparent in how the public and media view accidents. This viewpoint is reinforced by findings such as when an airline accident was caused by “pilot error”. Police citations are another example of the perception.
CHAIN OF EVENTS CONCEPT
The chain of events concept or domino theory was originally developed by Heinrich (1941). The basic concept implied that accidents resulted from a sequence of events that led to an accident. Like a row of dominos, once the sequence began each event led to the next until an accident occurred. Intervention at any point along the events sequence could halt the accident process and eliminate the unwanted results. An unsafe act starts the chain of events that began with an unsafe condition.
This concept is limited by the linear progression characteristic of the model. Interactions among events, contributing causes, and the duration and timing of each event limit the identification of all causal factors.
The current use of this concept is prevalent in the legal field that attempts to reconstruct the sequence of events that led to the accident.
2.the determinat variable concept
3.the domino theory
4.the fault tree analytical methodology
FAULT TREE ANALYSIS
Heinrich (1941) developed the methodology that preceded and formed the basis for Fault Tree Analysis. He illustrated the linear sequence of factors in accident causation by using a domino theory. The theory stated that a disturbance that caused any one of the five identified components of the sequence to fail would set off a chain-of-events that led to an accident. The five in the sequence were 1) ancestry and social environment, 2) conditions and fault of person, 3) unsafe act, 4) unsafe condition and 5) injury. He showed that by intervention at any point along the sequence an accident/injury could be prevented. This theory has been modified and updated (Baker 1953, Marcum 1978, Heinrich et al 1980), and has wide applicability in current automobile accident and law enforcement investigations.
Similar linear sequence models such as Critical Path Analysis (CPA), Gantt Charts, and Program Evaluation Research Task (PERT), were initially used in the 1950’s and 60’s as planning tools (Lockyer 1964). Though many names were given to their process they were very similar in their goals and methods. They provided a graphical display of activities linked to events by arrows in order to plan complex projects. The process illustrated a flow (path) from one task sequence to the next and incorporated time frames and interrelationships between tasks. Projects could then be analyzed by task, the amount of time needed for each segment and the relationship a task may have with another task. These methods offered an effective means of project planning, costs analysis, and time frame considerations by visually outlining the task process (Lockyer 1964). These processes also provided the means to better understand the interrelationships between and among tasks. This logical depiction of process flow related directly to analyzing an accident sequence and the precursor events.
In the 1960’s Bell Laboratories expanded upon the linear chain of events concept through missile system safety. They arranged events in a flow chart that used a proceed/follow logic pattern. Their concept, Fault Tree Analysis (Figure 11), is generally credited to Watson (1971). Figure 12 illustrates the fault tree concept as applied to a hypothetical accident where a wildland firefighter was burned. This analysis concept helped provide a sense of management by objectives by identifying unwanted events (the top event) and then systematically and sequentially determining the precursor events. The objective is the top event and the identification of the preceding causal factors aid in the management achievement of that objective. Watson’s Fault Tree Analysis investigation methodology provided a visible, easily understood and defendable format (1971). The methodology extended the linear chain of events into a “branched events chains” concept through the use of “and/or” logic gates. It uses basic Boolean logic in a hierarchical tree format. Other Boolean terms such as “not” are not used in Fault Tree Analysis. For example, “C” can only occur when both “A” and “B” occur. If two or more events are required for a cause to