Worstcase

Worstcase, often written as worst-case, is a concept used across disciplines to denote the most adverse outcome possible under a defined set of conditions. It contrasts with best-case and average-case analyses and with typical real-world observations. In probability and statistics, the worst-case outcome refers to the maximum value of a random variable within its sample space and is used to establish conservative bounds and safety margins.

In computer science, worst-case analysis describes the upper bound on resources such as time or memory for any input of size n. The worst-case running time provides a guarantee that the algorithm will not exceed that bound, regardless of input distribution. Worst-case space complexity concerns the maximum memory usage.

In risk assessment and engineering, worst-case planning considers the most damaging plausible events and their consequences to guide mitigation, resilience, and contingency planning. It is a core element of safety standards, reliability engineering, and disaster preparedness.

Limitations: focusing exclusively on worst-case scenarios can be overly pessimistic or unrepresentative of typical conditions. Analysts often supplement worst-case analysis with probabilistic, average-case, or stress-testing approaches to obtain a fuller picture.