100regel

100regel is a term used in planning and evaluation to describe a rule of thumb that reduces complexity by focusing analysis on a limited set of elements. In its general form, the rule suggests that examining around 100 items—such as features, cases, or factors—provides a practical proxy for the behavior of a larger system, while adding more detail yields diminishing returns. The concept appears in Dutch, Scandinavian, and northern European professional contexts, with the exact interpretation of the number 100 varying by domain.

The origin of the term is not tied to a single identifiable source. It is described as a pragmatic heuristic that arises in fields such as project management, product design, and risk assessment to balance thoroughness with limited resources. In practice, it is used to guide where to invest time and effort during analysis and decision making.

Applications of 100regel include sampling strategies, prioritization, and testing. For example, teams may concentrate validation on the 100 most-used features or on the 100 most probable failure modes, aiming to capture the majority of outcomes without exhaustive checking.

Variants of the concept exist, with adjustments to the threshold (such as 50regel or 200regel) to fit project size and risk tolerance. Some versions emphasize practical, hands-on heuristics rather than formal statistical methods.

Criticism focuses on the potential for oversimplification. Fixed numbers can neglect long-tail effects, rare but important scenarios, or contextual nuances, leading to a false sense of completeness. Proponents counter that, when used with awareness of limitations, 100regel can improve efficiency without sacrificing essential insight.

See also: Pareto principle, heuristics, sampling theory.