Incident Analysis Methods
VIJAIARASAN P.A(MIIRSM)(Tech IOSH)
Environment, Health and Safety Manager at Danieli Group
Introduction:
The models used in accident investigation can typically be grouped into three types: sequential, epidemiological, and systemic models. Although the sequential and epidemiological models have contributed to the understanding of accidents; they are not suitable for clarifying the complexities and dynamics of modern sociotechnical systems.
In these systems, the interactions and events are connected in complicated ways, and standard safety engineering techniques alone are not sufficient to comprehend the accident causation. When analyzing major accidents in process industries, a more systematic and professional model is needed than when supervisors and workers are investigating a normal minor accident in a simple setting.
What are incidents?
An incident is an unplanned event or chain of events that results in losses such as fatalities or injuries, damage to assets, equipment, the environment, business performance, or company reputation. A near miss is an event that could have potentially resulted in the above-mentioned losses, but the chain of events stopped in time to prevent this. These incidents can be classified in all kinds of severities and types, and thus into categories. Investigation and cause analysis should take these different categories into consideration.
Purpose of investigation:
The purpose of this Incident Investigation Guide is to provide employers a systems approach to help them identify and control the underlying or root causes of all incidents in order to prevent their
recurrence.
The Bureau of Labor Statistics reports that more than a dozen workers died every day in American workplaces in 2013, and nearly 4 million Americans suffered a serious workplace injury. And tens of
thousands are sickened or die from diseases resulting from their chronic exposures to toxic substances or stressful workplace conditions. These events cause much suffering and great financial loss to workers and their families and also result in significant costs to employers and to society as a whole. Many more “near misses” or “close calls” also happen; these are incidents that could have caused serious injury or illness but did not, often by sheer luck. Practically all of these harmful incidents and close calls are preventable.
All incidents – regardless of size or impact – need to be investigated. The process helps employers look beyond what happened to discover why it happened. This allows employers to identify and correct shortcomings in their safety and health management programs.
Incident investigations help employers:
The Need for a Methodology:
One fascinating yet troubling phenomenon that often goes unnoticed during incident investigations is that individual beliefs play a major determining role in the outcome because those outcomes depend partly on where the investigators believe the root cause lies. This includes opinions and
assumptions the investigator has at the beginning along with prejudices formed along the way. It goes even deeper than individual beliefs about how accidents happen, however. Even experienced and well-trained safety professionals sometimes are biased in that they support causation models which may not tell the full story of how incidents came about.
Frequently, an investigation team’s bias can result in narrowly-focused cause analysis. This shortcoming can result in avenues of investigation being left unexplored, which can happen when investigation teams are influenced by their preconceived notions, or jump to conclusions.
Rarely is a single factor to blame in isolation for an event that results in serious harm. An important lesson is that “disasters are very rarely the product of a single monumental blunder.” Thorough root cause analysis often uncovers surprising results, which underscores the reason letting preconceived notions guide the process may result in never finding the real cause. Worse yet, failing to mitigate the actual root cause puts lives and assets at continued, preventable risk. Indeed, there’s prevailing and persistent misinformation in the industry, causing many EHS professionals to mismanage their incident investigation initiative.
Getting past assumptions:
Many practitioners are misguided by a persistent myth in the industry. The myth that’s persisted for at least half a century is that workers committing unsafe practices are the cause of most incidents in the workplace. It has been stated2 that the causes of industrial accidents could be broken down in this way:
Believe it or not, many of the incident investigations performed even today are permeated by this 88-10-2 formula. It’s still?taught in educational programs at universities and is therefore extremely entrenched in the incident management community. Due to a lack of knowledge and bad beliefs, many EHS Professionals are not using effective causation models.
The persistence of this type of misconception is one of the major reasons why companies find a rigorous incident investigation methodology to be an incredibly helpful and powerful addition to their EHS program. A well-defined investigation methodology assists investigators in finding the ac that can be implemented.
METHODOLOGIES & MODELS:
n investigation methodology is how you think about, understand and resolve the root causes of an incident. While software can support the process, the right methodology must first be selected and implemented.
The incidents we investigate— accidents and near misses—almost never result from one cause. Most of them involve multiple, interrelated causal factors. This complexity should also be reflected in the investigation methodology used. Selecting the right one for your situation can be challenging.
Before we dive into some example methodologies, let’s look at some analytical models. This will help us think about the methodologies in the following sections.
Systemic models
focus on the systems and processes of the organizational culture and leadership to understand accident causes as mismatches or failures between those components.
Logical tree models
attempt to analyze the causes of accidents as a set of events and conditions, paying particular attention to the logical relationships between them.
Sequence-of-Events
(Domino, or Causal-sequence) models evaluate accidents as a continuous set of failures that set off a chain reaction.
Epidemiological models
from the medical term for the spread of disease, investigate accidents as emanating from hidden failures across all organizational components, including management, procedure, and design.
Energy model
rooted in epidemiology, focuses on the transfer of energy causing injury to a person, and therefore seeks to find ways to prevent such a transfer.
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Process models
focus on ways in which a production system can deteriorate over time, making a clear distinction between a sequence of events and any underlying causal or contributing factors.
Human information-processing models
analyze the situation from the perspective of a human operator and his interaction with his environment.
SYSTEMATIC CAUSE ANALYSIS TECHNIQUE (SCAT)
The International Loss Control Institute (ILCI) developed SCAT about 20 years ago for the purpose of occupational health and safety incident investigations.
SCAT is a systemic Model focused on the systems and processes of the organizational culture and leadership and is based on root cause analysis methods. This methodology provides a chart with a
series of cross-referenced categories. The investigator must identify the relevant factors by working systematically through the chart and identifying the contributing factors within each category.
Issues that lead to an incident are described as points at which the organization loses control over deficiencies, which in turn led to the undesired outcome.
In other words, SCAT asks investigators to go back before the cause of the problem to where the roots of that cause were formed. One cause might be inadequate leadership, for example. The following figure depicts the pathway of investigation in the SCAT method. As illustrated below, five main points - lack of control, basic causes, immediate causes, incident, and loss - are used in this type of?systemic technique.
?SCAT: Systematic Cause Analysis Technique
MANAGEMENT OVERSIGHT & RISK TREE (MORT)
The Management Oversight and Risk Tree (MORT) is an analytical procedure for determining causes and contributing factors. It arose from a project undertaken in the 1970s to provide the U.S. Nuclear industry with a risk management program competent to achieve high standards of health and safety.
MORT, a logical tree model, is based on Fault Tree Analysis (FTA), a top-down, deductive failure analysis procedure used to analyze causes and related factors of an undesired state using Boolean logic to combine a series of lower-level events and precursors.
Fault tree analysis maps the relationship between faults, subsystems, components, and controls by creating a logic diagram of the overall system.
Every sufficiently complex system is subject to failure as a result of one or more individual components failing.
MORT uses a comprehensive analytical procedure that provides a disciplined method for determining the causes and contributing factors of major accidents. The method can also be used to proactively evaluate the quality of an existing system.
Accidents are defined as unplanned events that produce losses when a harmful agent comes into contact with a person or asset. This contact can occur because of a failure of prevention or as an unfortunate, but acceptable, the outcome of a risk that has been properly assessed and assumed. Most of the effort is directed at identifying problems in the control of a work process and deficiencies in the barriers involved, as in:
1. a vulnerable target exposed to...
2. an agent of harm in the...
3. absence of adequate barriers.
The MORT methodology is less used today as a whole, but the charting technique is fairly common.
SEQUENTIAL TIMED EVENTS PLOTTING (STEP):
A technique that can be used to depict a basic timeline of an incident is the Sequential Timed
Event Plot5 is also known as a STEP diagram. Events, activities, and state changes can be organized into a single diagram in a sequence-of-events analytical model.
The timeline can focus primarily on ‘what’ happened (the events) and less on why things happened (the causes). This is because there may be multiple (interacting) causes for any event on the timeline and causes may not be close together in time or place.
While other methodologies may be more helpful to identify the root causes of accident consequences, STEP can be extremely beneficial for understanding the interaction between multiple factors and outcomes. The timeline-based approach clearly and concisely gives a picture of the ‘what’ and ‘when’ to allow investigation teams to work backward the ‘why’ and the ‘how’.
STEP is a multilinear systems approach that views accidents as multiple avenues of causal factors that are interrelated and interact with other factors throughout the system to ultimately lead to an accident.
The STEP procedure relies on a worksheet that provides structure, visibility, and organization to data gathering and analysis. It graphically represents the beginning and end of an accident sequence, detailing actors and actions over time. The procedure accommodates events that occurred at the same time. These events allow investigators to visually recreate the mental map of a sequence of events and determine gaps.
MANY OTHER AVAILABLE METHODS
There are several popular methodologies available which require license fees and are strictly controlled under copyright. Therefore, the use of such a methodology might limit your options when obtaining training for your staff, and your ability to modify or evolve the methodology for your
particular industry or organization. However, if you are looking for an out-of-the-box solution, these
methodologies are fairly common and well-respected by many organizations.
Still, other tools are prevalent and not so strictly controlled. Consider these if you want some readily available training, yet also the flexibility to modify the methodology for your own unique circumstances.
Some examples include
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