And make sampling randomly. Each Department staff (milling and cutting Department, Assembly Department, forming, painting and polishing and quality inspection departments, and packaging).
And by random sampling. Each department employees (Department handlers and cutting, molding department, assembly department, department scrub and paint. And quality inspection department and packing).
The sampling randomly. Each employee Department (Department of planing and cutting department, assembly department, molding department ชิ้นง, scrub and paint, and quality inspection departments and packing products).