Based on the above discussion we can understand the definition given by a few statisticians. They are:

“A time series consists of statistical data which are collected, recorded over successive increments”.

“When quantitative data are arranged in the order of their occurrence, the resulting statistical series is called a time series”.

The analysis of time series is of great utility not only to research workers but also to economists, businessmen and scientists etc., for the following reasons:

1) It helps in understanding past behavior of the variables under study.

2) It facilitates in forecasting the future behavior with the help of the changes that have taken place in the past.

3) It helps in planning future course of action.

4) It helps in knowing current accomplishment.

5) It is helpful to make comparisons between different time series and significant conclusions draw therefrom.

Thus, we can say that the need for time series analysis arises because:

• we want to understand the behavior of the variables under study,

• we want to know the expected quantitative changes in the variable under study, and

• we want to estimate the effect of various causes in quantitative terms

In a nutshell, the time series analysis is not only useful for researchers, business research institutions, but also for Governments for devising appropriate future growth strategies.