Guest blog by Prof. Luca Fiorentini and Prof. Luca Marmo

A good investigator collects evidence, analyzes them, finds the root causes and the relations among these causes that lead to the accident and provides suggestions about corrective actions to avoid the reoccurrence of the undesired event. In this blog, Prof. Luca Fiorentini and Prof. Luca Marmo show why its important for investigators to focus on the system rather than the individual.

Going beyond the widget in industrial incident analysis!

When investigating an industrial accident or a near-miss, the primary goal is not to find a concise fault of a well-defined widget, confined to a distinct domain. A rigorous approach to the forensic discipline requires going much deeper in the investigation, not stopping at the main relevant evidence, even if properly gathered and analyzed. It often happens that accident reports are one-dimensional [1]: in other words, they identify only a single cause, usually corresponding to the outer layer of the complexity that surrounds the reconstruction of the incidental dynamics. Even when multiple causes are discovered, the investigator seldom looks beyond them.

The complexity of industrial incidents

In the industrial context, a complex system of relations, information, and people is present, with their peculiarity and hierarchy, creating a structured entity that needs to be considered when investigating an accident or a near-miss. Thus, it becomes necessary to consider an investigation of the management systems as well. Some causes of the accident may be related to management failure and you want to take the corrective actions and to prevent a further similar failure. A good investigator does not find culprits and does not blame. A good investigator collects evidence, analyzes them, finds the root causes and the relations among these causes that lead to the accident. Considering managerial duties, as usually happens, provides suggestions about corrective actions to avoid the reoccurrence of the undesired event.

The onion-like structure of causes

Focusing on the system, rather than the individual, represents the right way to face an investigation, for at least three reasons [2]. Firstly, if equipment and systems provided to persons reveal to be not effective, it is not the individual responsibility that has to be pointed out as the fault cause. Secondly, it is much easier to change a managerial choice rather than a person’s behaviour, which is susceptible to vary daily. Thirdly, human errors may often be the consequence of insufficient training, motivation or attention to safety, all being aspects that the management should promote and monitor.

It is a matter of controllability and reliability, as these are the two most essential ingredients to ensure that the lesson learnt will guarantee an increasing or restoration of the safety level accepted in the industry at the corporate, field and line levels. Metaphorically speaking, an accident investigation is like peeling an onion: this concept[3], gives us a live image of what we are called to solve. Technical problems and mechanical failures are the outer layers of the onion: the immediate causes. Only once you peel these off you can find the inner layers: the underlying causes, like those involving the management weaknesses.

Figure 1: The onion-like structure between immediate causes and root causes

Going beyond the widget is what a professional investigator does. Let us consider a relief valve that fails, causing injuries to the line operators. A neophyte may conclude: “It was a fault in the relief valve. The case is closed, people”. On the contrary, a good investigator may wonder: “Is it a consequence of an unexpected running condition, exceeding the operational limits? Was there an erroneous maintenance procedure? Was it installed correctly? Is it a result of an entire procurement of damaged relief valves?”. The differences between these two extreme examples are clear: it is highly recommended to cover at least the following three levels in the investigation: line, field, and corporate levels. This good practice should suggest what a proper investigation requires: project management and a variously skilled team of investigators.

The incident investigation requires project management skills

Conducting an investigation means to plan the activities, organize meetings, schedule recognitions of the accident area, inform and be informed, commission tests to external laboratories and manage resources (mainly time and budget). However and most of all, conducting an investigation means linking the collected elements in a multidisciplinary network. To do this, you need to combine many different skills. Many people get confused about how to conduct an investigation. The best way to face such a complex challenge is to consider it as an ordinary project in which you require: organizational and managerial skills, listening capacity and a problem-solving attitude. These are the desirable features of the investigator.

Root causes to be identified starting from the complexity of an industrial accident

The recent approach in accident investigation reflects the simple concept discussed in this blog. Over the past decade, a transition has indeed occurred not only in the way accidents are investigated but also in the way they are perceived [4]. Once again the transition has shown an increasing focus on the organizational context, rather than the technical failures and human errors. This transition is also fed by the public opinion, which is formed after an industrial accident. Public, and of course stakeholders, desire to understand the real root causes of an accident, not only the “simple” mechanism or the timeline of the event.

This transition caused new methods to arise for industrial accident analysis. The attention of these methods is focused on the so-called “organisational network”. The main objective is to reconstruct the real accidental phenomenon empirically, exploring the theoretical organisational structures. The goal is very ambitious and hard. It requires a multiplicity of transversal scientific skills, attitude, intuition and managerial capabilities. It requires ground competencies to find, gather and analyse the evidence that may be the trace of precursor events.

Following this investigation methodology, time becomes reversible. In other words, it is always possible to cross the time domain in both its directions, because of the bi-unique relationship between cause and effect. The knowledge is complete, and the perceived complexity is only apparent because of the human incapability in thoroughly reading this world. However, if you insert the idea of a failure in the theory of complexity, then conclusions change. The attention is now focused not only on the individual components of the system but also on their relationships. Facing complexity is a challenge requiring a strong capability to deal with sociotechnical systems, safety systems and resilience engineering. These are the main ingredients for more in-depth accident analysis [6]. Please note, with that being said, the reader should not confuse the attribute “complex” with “complicated”.

Learn more about “Principles of forensic engineering applied to industrial accidents”

The book “Principles of forensic engineering applied to industrial accidents”, recently published by Luca Fiorentini and Luca Marmo intends to present some methods to deal with the complexity associated with industrial accidents exemplified by means of real case studies.

Forensic engineering should be seen as a rigorous approach to the discovery of the root causes that lead to an accident or near-miss. The approach should be suitable to identify both the immediate causes as well as the underlying factors that affected, amplified, or modified the events in terms of consequences, evolution, dynamics, as well as the contribution of an eventual “human error”.

The book “Principles of forensic engineering applied to industrial accidents”, by Luca Fiorentini and Luca Marmo (ed. Wiley) is a concise and introductory volume to the forensic engineering discipline which helps readers to recognize the link among those important, very specialized aspects of the same problem in the global strategy of learning from accidents (or near-misses). Readers will benefit from a single point of access to this very large, technical literature that can be only correctly understood with the right terms, definitions, and links in mind.

Figure 2: Book cover “Principles of forensic engineering applied to industrial accidents”

“Principles of Forensic Engineering Applied to Industrial Accidents” is essential reading material for researchers and practitioners in forensic engineering, as well as graduate students in forensic engineering departments and other professionals“. Pre-order the book on the editor’s website.


[1] Kletz T. Accident investigation – Missed opportunities. Hazards XVI: Analysing the Past, Planning the Future. Manchester: Institution of Chemical Engineers; 2002. p. 3-8.
[2] Sutton I. Process Risk and Reliability Management. Burlington: William Andrew, Inc; 2010.
[3] Kletz T. Learning from accidents. 1st ed. Oxford: Gulf Professional; 2001.
[4] Dien Y, Llory M, Montmayeul R. Organisational accidents investigation methodology and lessons learned. Journal of Hazardous Materials. 2004;111(1-3):147-153.
[5] Dekker S, Cilliers P, Hofmeyr J. The complexity of failure: Implications of complexity theory for safety investigations. Safety Science. 2011;49(6):939-945.
[6] Pasman H. Risk analysis and control for industrial processes. 1st ed. Oxford: Elsevier Butterworth-Heinemann; 2015.