Technical investigations rarely begin with complete information or an obvious answer. The methodology applied is therefore designed to develop a reliable understanding from the available evidence while remaining transparent about assumptions, uncertainties, and limitations. The individual steps outlined below do not necessarily occur sequentially and may be revisited as new information becomes available.
Review Available Evidence
Engineering investigations begin with a review of the available evidence. Depending on the assignment, this may include physical evidence, technical documentation, operating records, inspection findings, maintenance records, correspondence, witness accounts, photographs, test results, or other relevant information.
Particular attention is given to the quality, completeness, relevance, and traceability of available evidence, as these factors ultimately influence the confidence that can be placed in subsequent conclusions.
Identify Assumptions
No investigation is entirely free of assumptions. Assumptions may arise from incomplete information, unavailable evidence, limitations in testing, or uncertainty regarding historic events and operating conditions.
Relevant assumptions are identified explicitly wherever practicable and are revisited as additional information becomes available.
Consider and Develop Alternative Explanations
Initial observations often permit more than one plausible explanation. Developing and evaluating alternative explanations helps reduce the risk of premature conclusions and ensures that explanations are tested against the available evidence rather than selected because they appear intuitive or convenient.
Competing hypotheses are considered, developed, and compared on the basis of technical merit and evidentiary support.
Assess Causality
Identifying a failure mechanism is not necessarily the same as identifying its cause. Technical, operational, organizational, and environmental factors often interact and contribute simultaneously to an outcome.
Causality is assessed by examining the relationship between observed evidence, contributing factors, and resulting consequences, with the objective of establishing technically credible and defensible conclusions.
Document reasoning
Conclusions are most valuable when the reasoning leading to them can be understood and independently reviewed. Documentation therefore aims not only to record findings, but also to explain how those findings were reached.
This traceability supports transparency, consistency, and the ability of others to evaluate the strength of the conclusions presented.
Communicate Limitations
Every investigation is subject to limitations. Evidence may be incomplete, degraded, unavailable, contradictory, or influenced by practical constraints.
Such limitations are identified and communicated together with their potential impact on findings, conclusions, and recommended actions.
Cognitive Bias Awareness
Engineering investigations are performed by people and are therefore susceptible to cognitive biases that may influence judgement and interpretation. Examples include confirmation bias, anchoring, hindsight bias, and availability bias.
Awareness of such influences is actively fostered through critical review of assumptions, consideration of alternative explanations, and continuous evaluation of whether conclusions remain supported by the available evidence.