The design of waist province is related to the hip-waist difference. When the hip-waist difference is greater than 24cm, the front and rear parts are two provinces. When the hip-waist difference is below 24cm, the front and rear halves are collected in one province each.

The role of savings is to solve the hip-waist difference. The size of the province is based on the difference between hip circumference and waist circumference.

H-W= potential of side crack splitting+sum of all savings.