- The point estimator of based on the data
is defined by

- The point estimator is said to be unbiased for
if

In general

i.e. there is a drifting, or bias. - For continuous data, the point estimator of based on data
, where is the simulation run length,
is defined by

and is called a time average of*Y(t)*over . - In general

if*b*= 0, is said to be unbiased for - One performance measure of these estimators (point or interval)
is a quantile or a percentile.
- Quantiles describe the level of performance that can be
delivered with a given probability
*p* - Assume
*Y*represents the delay in queue a customer experiences, then the 0.85 quantile (or 85% percentile) of*Y*is the value such that

- Quantiles describe the level of performance that can be
delivered with a given probability