Conventional way needs 5 WIPs, which are insole cementing, number stamping, tuck board skiving, tuck board cementing, insole and tuck boards pressing and attaching.
These processes require 5 labors and 4 machines.
After the prototype has been field tested on mass production line in shoe factories and approved by shoe brands QC, it's then become available for mass orders to help shoe factories reduce labors and WIP and increase product quality and profit with standardization.
