Solution to the indexing problem of frequency domain simulation experiments

The authors discuss why the global simulation clock time is the most natural choice for the frequency-domain simulation experiment (FDE) oscillation index. The reasons behind the failure of past efforts to reference all the frequencies in a FDE to the global simulation clock are also presented. A novel methodology for performing frequency-domain analysis of discrete-event simulation experiments is proposed. This methodology is based on the Fourier (spectral) analysis of stochastic systems and uses the global simulation clock time as the oscillation index. The histogram method for implementing this methodology is discussed. Using this method, it is possible to analyze stochastic systems subject to nonstationary inputs, a difficult analytical problem. The effectiveness of this method is demonstrated by applying it to a single-server FIFO queue and a network of single-server queues. The method is efficiently implementable, resilient to noise, and lends itself efficiently to any simulation model being analyzed using frequency-domain methods