Stress-testing systems: A guide to the assessment of compound and cascading risk

Stress tests are a useful method for measuring a system’s exposure to multiple threats. In stress tests, scenarios are crucial, however the ones frequently utilised usually fail to consider inner, more contextual and social elements. Consequently, adaptation opportunities may be lost and hazards may be underestimated. Stress testing reveals the vulnerabilities of specific systems (projects, plans, etc.) to different risk scenarios, both climatic and non-climatic. Furthermore, traditional stress testing exercises are often limited in the stakeholder engagement. More collaborative and multi-hazard stress testing helps connect risk information with scenario planning and adaptation options by examining a wide range of scenarios. As a result, the information leveraged by projects from the humanitarian and development sectors can strengthen this approach by identifying weak points in projects and the design of activities.

This stress testing guide is a collaborative exploration to define where and how potential impacts may put excessive stress on a system. In some cases, it can also be used to test adaptation options. This guide is intended as a bottom-up exploratory approach to identifying the vulnerabilities of specific systems to various possible stressors and scenarios. It is envisioned as a flexible and generally applicable guidance document. As a flexible tool, the implementation and format of the test can vary depending on the system or unit of analysis being tested (e.g. size, type and core functions of a system), what stressors are taken into consideration (e.g. climate, urbanisation, economic, shocks, etc.), whether adaptation options should be included, and what type of information and other resources are available.

The stress testing guide provides a clear step by step process to apply this method in multi hazard risk context, including cartoons and reference to a series of hands-on processes that can be used in the testing process.