Poisson and non-Poisson properties in appointment-generated arrival processes: The case of an endocrinology clinic

Previous statistical tests showed that call center arrival data were consistent with a non-homogeneous Poisson process (NHPP) within each day, but exhibit over-dispersion over multiple days. These tests are applied to arrival data from an endocrinology clinic, where arrivals are by appointment. The clinic data are also consistent with an NHPP within each day, but exhibit under-dispersion over multiple days. This analysis supports a new Gaussian-uniform arrival process model, with Gaussian daily totals and uniformly distributed arrivals given the totals.