“…If environmental factors such as economic and marketing conditions change during the product life and have a significant effect on the demand, then the assumption that the demand in each period is a random variable and is independent of environmental factors apart from time will be incorrect. In such real life situations, the Markov chain approach provides a flexible alternative for modeling the demand process [55,276,321,335,336,[339][340][341][343][344][345][346]; not only does it significantly generalize the Poisson process [55,272,278,280,281,287,290,297,303,304,307,308,316,333,338,341], but it is also a convenient tool for modeling both the renewal and non-renewal demand arrivals. However, despite this fact, the Markovian assumption holds for demand processes with relatively low variation coefficients, i.e., in cases where high demand variances are observed, the non-stationary assumption does not hold in the Markovian environment because standard periods of constant length may introduce memory and generate correlated demand distributions within periods.…”