Are Call Center and Hospital Arrivals Well Modeled by Nonhomogeneous Poisson Processes?

@article{Kim2014AreCC,
  title={Are Call Center and Hospital Arrivals Well Modeled by Nonhomogeneous Poisson Processes?},
  author={Song-Hee Kim and W. Whitt},
  journal={Manuf. Serv. Oper. Manag.},
  year={2014},
  volume={16},
  pages={464-480}
}
Service systems such as call centers and hospitals typically have strongly time-varying arrivals. A natural model for such an arrival process is a nonhomogeneous Poisson process (NHPP), but that should be tested by applying appropriate statistical tests to arrival data. Assuming that the NHPP has a rate that can be regarded as approximately piecewise-constant, a Kolmogorov–Smirnov (KS) statistical test of a Poisson process (PP) can be applied to test for a NHPP by combining data from separate… Expand
Choosing arrival process models for service systems: Tests of a nonhomogeneous Poisson process
Service systems such as call centers and hospital emergency rooms typically have strongly time-varying arrival rates. Thus, a nonhomogeneous Poisson process (NHPP) is a natural model for the arrivalExpand
Staffing many‐server queues with autoregressive inputs
TLDR
A multiserver queueing system where customer arrivals follow a doubly stochastic Poisson point process whose intensities are driven by a Cox–Ingersoll–Ross (CIR) process is studied, finding that, in order to achieve the designated service level, such an autoregressive feature in the arrival model translates into notable adjustment in the staffing formula, and such an adjustment can be fully characterized by the parameters of the new arrival model. Expand
3 The Relevant Time Scale for Staffing : Short and Long Service Times
Motivated by non-Poisson stochastic variability found in service system arrival data, we extend established service system staffing algorithms using the square-root staffing formula to allow forExpand
STAFFING A SERVICE SYSTEM WITH NON-POISSON NON-STATIONARY ARRIVALS
TLDR
A general model of the non-Poisson non-stationary arrival process is developed that includes as a special case the non -stationary Cox process (a modification of a Poisson process in which the rate itself is a non- stationary stochastic process), which has been advocated in the literature. Expand
Rate-Based Daily Arrival Process Models with Application to Call Centers
TLDR
New stochastic models for the daily arrival rate in a call center, with explicit formulas for the relationship between the correlation between rates and that between counts in two given periods, and for the variance and dispersion index in a given period are proposed. Expand
Queues with Time-Varying Arrivals and Inspections with Applications to Hospital Discharge Policies
TLDR
A queueing system with time-varying arrival rates in which servers who have completed service cannot be released until an inspection occurs and Leveraging insights from an infinite-server model, this work is able to optimize the timing of inspections. Expand
Rare-event analysis of mixed Poisson random variables, and applications in staffing
TLDR
A mixed Poisson arrival process with arrival rates that are resampled every N−α time units, where α>0 and N a scaling parameter is considered, and the asymptotic tail distribution of this doubly stochastic arrival process is analyzed. Expand
Stationary Birth-and-Death Processes Fit to Queues with Periodic Arrival Rate Functions
To better understand what queueing models are appropriate for complex service systems such as hospital emergency departments, we suggest fitting a general state-dependent birthand-death (BD) processExpand
Some results for inhomogeneous birth-and-death process with application to staffing problem in telecommunication service systems
TLDR
It is shown that if the service system is modelled by multiserver queue Mt/Mt/S with state-dependent periodic arrivals, services and breakdown rates, then using obtained results one can calculate the quantities needed for the solution of optimization problem. Expand
Poisson and non-Poisson properties in appointment-generated arrival processes: The case of an endocrinology clinic
TLDR
This analysis supports a new Gaussian-uniform arrival process model, with Gaussian daily totals and uniformly distributed arrivals given the totals. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 49 REFERENCES
Choosing arrival process models for service systems: Tests of a nonhomogeneous Poisson process
Service systems such as call centers and hospital emergency rooms typically have strongly time-varying arrival rates. Thus, a nonhomogeneous Poisson process (NHPP) is a natural model for the arrivalExpand
On the modeling and forecasting of call center arrivals
TLDR
The key issues in building statistical models for the call arrival process in telephone call centers are reviewed, and various types of models proposed so far are surveyed and compared. Expand
Statistical Analysis of a Telephone Call Center
TLDR
An analysis of a unique record of call center operations that comprises a complete operational history of a small banking call center, call by call, over a full year is summarized. Expand
Modeling Daily Arrivals to a Telephone Call Center
TLDR
Stochastic models of time-dependent arrivals are developed, with focus on the application to call centers, including the essential features of the arrival process, the goodness of fit of the estimated models, and the sensitivity of various simulated performance measures of the call center to the choice of arrival process model. Expand
On a Data-Driven Method for Staffing Large Call Centers
TLDR
A simple and computationally tractable method for solving this problem that requires as input only a few system parameters and historical call arrival data for each customer class is proposed; in this sense the method is said to be data-driven. Expand
Estimating the parameters of a nonhomogeneous Poisson process with linear rate
TLDR
Motivated by telecommunication applications, this work investigates ways to estimate the parameters of a nonhomogeneous Poisson process with linear rate over a finite interval, based on the number of counts in measurement subintervals, and develops statistical tests to determine whether the linear Poisson model is appropriate. Expand
Stabilizing Customer Abandonment in Many-Server Queues with Time-Varying Arrivals
An algorithm is developed to determine time-dependent staffing levels to stabilize the time-dependent abandonment probabilities and expected delays at positive target values in the Mt/GI/st + GIExpand
ON PATIENT FLOW IN HOSPITALS: A DATA-BASED QUEUEING-SCIENCE PERSPECTIVE
TLDR
The goal of the research is to explore patient flow data through the lens of a queueing scientist, and exploratory data analysis in a large Israeli hospital reveals important features that are not readily explainable by existing models. Expand
The Impact of Dependent Service Times on Large-Scale Service Systems
This paper investigates the impact of dependence among successive service times on the transient and steady-state performance of a large-scale service system. This is done by studying anExpand
Managing uncertainty in call centres using Poisson mixtures
We model a call centre as a queueing model with Poisson arrivals having an unknown varying arrival rate. We show how to compute prediction intervals for the arrival rate, and use the Erlang formulaExpand
...
1
2
3
4
5
...