Simple Linear Regression Simple linear regression measures the relationship between one variable (for example, staffing) against another variable (such as production output) and allows prediction of one variable from the other. For example, measuring the number of units produced against the number of employees producing the units over a period of years would allow the analyst to forecast the number of employees needed to meet an increase in demand.Multiple Linear Regression Multiple linear regression measures the relationship between several variables to forecast another. An application of this model in workforce planning would be to determine whether there is a relationship between lower staffing levels, absenteeism, and production output.