Shewhart Control Charts for Yarn and Fabric Properties
topic
Shewhart X-bar and R charts plot subgroup mean and range of yarn count, tenacity, elongation, and fabric weight measurements against three-sigma control limits calculated from process baseline data, with Western Electric run rules detecting non-random patterns including trends, cycles, and stratification that precede out-of-control process shifts.
Role
Provides the primary real-time process monitoring tool for spinning and weaving quality control rooms, enabling operators to identify developing process problems from statistical signals in routine quality measurement data before defect rates exceed customer specification limits and non-conforming product is produced.