An Event-Scale Fermi Estimation Model (ES-FEM) for Rapid Feasibility Assessment of Public Park Events

Evaluating feasibility and attendance projections for public park events is crucial for municipal planning, crowd safety, and resource allocation. Due to inherent uncertainty and lack of historical data in early-stage planning, precise forecasting is challenging. This paper proposes a rapid feasibility-screening framework—the Event-Scale Fermi Estimation Model (ES-FEM)—to evaluate whether projected attendance levels are physically and demographically plausible. By integrating spatial parameters, simultaneous crowd density, temporal turnover rates, demand-side marketing funnels, and infrastructure bottlenecks (min(N_space, N_infra, N_market)), ES-FEM provides an order-of-magnitude assessment under limited-information conditions. Drawing epistemological parallels with finite element method (FEM) preliminary sizing and cross-disciplinary order estimation, the model bridges the gap between rough back-of-the-envelope calculations and urban engineering constraints.