This article explores forensic engineering from the perspective of failure investigation. It highlights what constitute an engineering failure and how the forensic engineer approaches a failure investigation.
Failure investigation is a crucial process undertaken across various industries to identify the root causes of failures and prevent their recurrence. Whether it’s in engineering, manufacturing, or any other field, failures can lead to significant losses in terms of time, resources, and even lives.
When we think of failures within the context of structural engineering, many simply take it that the word failure simply implies catastrophic structural collapse, which most often will lead to the devastating loss of lives. This can be seen even by the way humanity react to failures. A failure that doesn’t involve the loss of lives does not relatively get as much clout as one that does. Even the featured image of this article depicts a failure as a catastrophic building collapse. However, just because a failure is not catastrophic shouldn’t imply that it is less of a failure. The leaning tower of Pisa is an engineering failure even though it has stood for centuries – of course the designers did not envisage it leaning status at the design stage. Thus, the ASCE expands the scope of what constitute an engineering failure by defining it as follows:
“Failures are not all catastrophic, such as when a building collapses, but include facilities or parts of facilities that do not perform as intended by the owner, design professional, or constructor.”
American Society of Civil Engineer’s
By the above definition, a failure doesn’t have to be catastrophic to constitute a failure. A simple deficiency in the building material used could pass for a failure. Gerald Leonard’s succinctly put it that: “a failure is an unacceptable difference between expected and observed performance.”
To effectively address failures, a structured approach is necessary. An entire niche of engineering has been formed, dedicated to the practice of investigating engineering failures known as forensic engineering. Forensic engineering is the application of engineering principles to the investigation of failures or other performance problems. Forensic engineering also involves testimony on the findings of these investigations before a court of law or another judicial forum, when required2.
This article is concerned with the guidelines of failure investigation. It provided five common steps as posited by ASCE for failure investigation known as the forensic investigation process. This includes investigation planning and coordination, data collection, development of testing protocol, data analysis and interpretation, and presentation of opinions and conclusions.
The Forensic Investigation Process
The forensic investigation process has been listed in the last section. Depending on the nature and magnitude of the failure and the suitability of the approach to the investigation, some of these steps may be altered, expanded, or occasionally omitted as long as it does not compromise the findings of the investigation. For minor failures of a single component or part of a structural system, this process may be conducted by a single investigator in a matter of hours. However, for a major structural collapse, this process may require the collaborative efforts of a multidiscipline team of investigators for several years. Most failures involve multiple contributing factors, requiring multiple forensic consultants.
Investigation Planning and Coordination
The first step in any failure investigation process is meticulous planning and coordination. This involves defining the scope of the investigation, setting objectives, and assembling a multidisciplinary team with the requisite expertise. Clear communication channels must be established, and roles and responsibilities should be defined to ensure efficient collaboration.
It is at these phase that a forensic engineer must determine if they have the required staffing requirement, experience and competence to conduct the investigation. If the engineering failure is outside the core competence of the engineer, the assignment should be declined or referred to a more competent hand. As the forensic engineer, you’re also required to consider if there is any conflict of interest that may arise in the discharge of your duties. Or any legitimate concerns that may lead to your opinions been perceived as bias.
The next thing to consider at this stage is the budget allowed giving the scope of the investigation. What is the importance of conducting the investigation given the economic consequences? A limited budget should not result in a hog-wash investigation. Even with a limited budget the investigation must be conducted to with integrity and the conclusion reached must be based on facts of evidence found and not uncertainty. Thus, the budget must be realistic to ensure that the failure investigation is worthwhile.
Also, during this phase, it’s essential to gather all available information related to the failure, including incident reports, historical data, and any relevant documentation. Conducting initial interviews with personnel involved in the incident can provide valuable insights and help in framing the investigation approach.
Data Collection
The investigation of failures in almost every field has one thing in common – the requirement for data analysis in other to understand what went wrong. In the context of forensic engineering process, data is used to understand what went wrong and to understand the circumstances leading to the failure and any contributing factors involved.
Data collection is a critical step that involves gathering relevant information and evidence related to the failure. This may include physical evidence, such as failed components or materials, as well as documentation, maintenance records, and witness accounts. Careful documentation of the collected data is essential to ensure its integrity and traceability throughout the investigation process.
Various techniques and tools may be employed during data collection, such as visual inspection, non-destructive testing, and forensic analysis. It’s crucial to adhere to established protocols and standards to preserve the integrity of the evidence and prevent contamination or tampering.
Development of Testing Protocol
Once the relevant data has been collected, the next step is to develop a testing protocol to systematically analyze the evidence and identify potential causes of the failure. What is the goal of collecting data which would typically include samples from the engineering failure, if not to conduct test?
At the initial stages of planning and coordination and even data collection, many hypotheses would’ve been formed, many of which can only be accepted or discarded by conducting tests. If any benefit is to be derived from conducting tests during a failure investigation, it must be based on appropriate testing standards A sound testing protocol is critical so that the interpretation of the results can be used as a firm foundation for drawing conclusions as to the cause of the failure.
A testing protocol should be carefully designed to address specific hypotheses and research questions formulated during the investigation planning phase. It’s essential to consider factors such as sample size, testing methodology, and statistical analysis techniques to ensure the validity and reliability of the results.
Data Analysis and Interpretation
Having conducted investigations, collected data, tested some of this data, the forensic engineer is now ready to analyze this data and interpret them. These include information collected from the site of the failure, project documents, literature research, and eyewitness account.
Data Analysis and interpretation is conducted based on Scientific Methods. The scientific method is an investigative process in which a problem is identified, relevant data are gathered, a hypothesis is formulated from the data, and the hypothesis is empirically tested. When a hypothesis is confirmed to an acceptable level of confidence it may be presented as a conclusion. In some cases, a level of confidence in the findings may be difficult to establish. In either case, a proper and thorough investigation and a fair presentation of the findings are necessary to prevent exposure of the investigator to questions regarding the validity of their investigation.
Thus, data analysis is a critical phase in the forensic investigation process where the collected evidence is scrutinized, and patterns or trends are identified to elucidate the root causes of the failure. This may involve quantitative analysis, such as statistical modeling or finite element analysis, as well as qualitative techniques, such as root cause analysis or fault tree analysis.
Interpretation of the data requires expertise and domain knowledge to discern relevant insights and draw meaningful conclusions. It’s essential to consider multiple perspectives and hypotheses while critically evaluating the evidence to avoid premature conclusions or bias.
Presentation of Opinions and Conclusions
The final step in the failure investigation process is the presentation of opinions and conclusions based on the findings. This may involve preparing detailed reports, presentations, or expert testimony to communicate the results of the investigation to stakeholders, regulatory authorities, or the public. Clarity, accuracy, and transparency is very essential when presenting opinions and conclusions to ensure credibility and facilitate informed decision-making.
The report should provide a narrative and graphic overview of the investigative process and findings, including opinions. Reports commonly include the history of the project, a description of the incident or failure, design considerations, analysis of the mode and causes of the failure, hypotheses or conclusions as to the causes of the failure and, in some cases, recommendations for remedial measures. Recommendations for corrective actions or preventive measures should be provided based on the identified root causes to mitigate the risk of future failures.
Conclusion
The failure investigation process is a systematic approach to identifying the root causes of failures and preventing their recurrence. By following the five common steps outlined in this article – investigation planning and coordination, data collection, development of testing protocol, data analysis and interpretation, and presentation of opinions and conclusions – structural engineer or intending forensic engineers can effectively address failures and improve the reliability and safety of their procedures of investigating failures. Effective collaboration, adherence to established protocols, and critical thinking are essential throughout the investigation process to ensure thoroughness and accuracy in identifying and addressing the underlying causes of failures.
Also See: Human Factors and Structural Failures
Sources & Citation
- Committee, on Forensic Investigations. Guidelines for Failure Investigation, edited by Richard Barrow, et al., American Society of Civil Engineers, 2018. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/istructe/detail.action?docID=5559980.
