The purpose of the provisions set forth in § 778.415 is to provide an exception from the requirement of computing overtime pay at not less than one and one-half times the regular rate for hours worked in excess of the applicable maximum hours standard for a particular workweek and to allow, under specified conditions, a simpler method of computing overtime pay for employees paid on the basis of a piece rate, or at a variety of hourly rates or piece rates, or a combination thereof. This provision is not designed to exclude any group of employees from the overtime benefits of the Act. The intent of the provision is merely to simplify the method of computation while insuring the receipt by the affected employees of substantially the same amount of overtime compensation.