在本文中，我們主要研究的目標是Ｅm/Ｅk/１模型的離去過程之相關性。 在此之前，不少學者作了很多有關M/G/1模型和G/M/1模型離去過程的相關性研究，但當等候理論中的“失憶性”(memoryless)這個重要的性質不再適用後，會產生什麼結果呢？ 為了解Ｅm/Ｅk/１的相關性，我們引入N-階段離去時間分配”(N-step interdeparture time distribution)的方法。藉由這個方法，我們可以計算出系統中離去間隔時間的期望值，E(DN)，二階期望值， E(D2N)，變異數，Var(DN)，共變異數，Cov(D1,DN)，和相關係數，Corr(D1,DN)。 / In this thesis, our goal is to study the correlation coefficients of the departure process in the E_m/E_k/1 model. Many authors conduct a lot of researches about the correlation coefficients of M/G/1 models and G/M/1 models. But what if the property of “memoryless" fails ? To realize the correlation coefficient of E_m/E_k/1, we derive the methodology of N-step interdeparture time distribution which was presented by Luh in 1999. By adopting it, we can calculate the expectation, E(D_N), second order expectation, E(D_N^2), variance, Var(D_N), covariance, Cov(D_1,D_N), and correlation coefficients, Cov(D_1,D_N) of the system.