This paper critically examines time series basics which are comprised of the assumptions, principles as well as conditions necessary for the analysis, and also the processes coupled in the use of MA, ARIMA and also ARMA or even AR. The data in this analysis was secondary obtained information of a flash tank of a given plant. The variable hourly, digester flow cut, low-pressure heater swap, and high-pressure FT online; each of which was distinct from one another. The named variables were analyzed separately. The number of observations on hourly data was 2990; digester flow cut 10096, high-pressure FT online 7295, and low-pressure heater swap 10096 records.