Normal standards:

These are standards that may be achieved under normal operating
conditions. The normal activity has been defined as “the number of standard hours which willproduce at normal efficiency sufficient goods to meet the average sales demand over a term
of years”. These standards are, however, difficult to set because they require a degree of
forecasting. The variances thrown out under this system are deviations from normal efficiency,
normal sales volume, or normal productive volume. If the actual performance is found to be
abnormal, large variances may result and necessitate revision of standards.