A systems framework for safety and security: The holistic paradigm

New discoveries coupled with the incessant desire to improve performance and reduce cost of products and services tend to encourage the deployment of novel technologies, which are often more complex in nature than their earlier counterparts. However, recent experience bears witness to the need for better vision and foresight in appreciation of the detrimental aspects alongside seemingly beneficial and rewarding facets of modern systems, processes, and products. Among many aspects to the performance of systems, safety is a human‐focused and complex socio‐technical issue. The classical view of safety is largely biased towards the causality of hazardous states and failure of products, processes, and systems, often taking a narrow technical reliability perspective in place of sensitivity to human dimension. Later philosophies have advocated the extension of failure‐based approaches to take into account assessment of likely accidents and consequent harm to people. Against this setting, security, which is a major and more recent concern, is analogous to safety, differing mainly in malicious intent and deliberate causation rather than unplanned random or systematic causes. This paper proposes a new paradigm for holistic systems assurance, of which safety performance and security/vulnerability are key aspects. While principally focused on safety assurance, the proposed paradigm is broadly applicable to any facet of a system's performance and goes beyond the current horizons of systems safety landscape. It develops and proposes a more inclusive approach and extension of current systems safety domain, comprising scope and issues beyond accident causation and consequential loss. It further advocates a more extensive view of loss, encompassing harm to people and damage to the natural habitat as well as detriment to a business enterprise or society at large. References to safety assurance in this paper are synonymous with ensuring health, safety, and welfare of people. © 2004 Wiley Periodicals, Inc. Syst Eng 7: 99–112, 2004