A simple run sequence plot of the original time series with time on *x*-axis and the variable on *y*-axis is good for indicating the following properties of the time series:

- Movements in mean of the series
- Shifts in variance
- Presence of outliers

The following figure is the run sequence plot of a hypothetical time series that is obtained from the mathematical formulation *x _{t} = (At + B) sin(t) + Є(t)* with a time-dependent mean and error

**that varies with a normal distribution**

*Є*(t)*N(0, at + b)*variance. Additionally, a few exceptionally high and low observations are also included as outliers.

In cases such as this, a run sequence plot is an effective way of identifying shifting mean and variance of the series as well as outliers. ...