The reject rates at the company's footwear production facilities are a function of such factors as

per worker expenditures for best practices training, the number of models$/$styles being produced, the number of hours of overtime pay production workers receive, and whether the production facility has installed production improvement option D$.$

the size of production workers' total compensation package, the percentage use of superior materials, and the $\frac{S}{Q}$ rating of the pairs being produced.

the $\frac{S}{Q}$ rating of the pairs being produced, the percentage use of superior materials, per worker expenditures for best practice training, and the installation of production improvement option $C.$

the size of worker's annual base pay, year$-$end incentive bonuses, the number of hours of overtime pay, the $\frac{S}{Q}$ rating of the pairs being produced, and the number of models$/$styles comprising the company's product line.

the size of the incentive payment per non$-$defective pair produced, per pair spending for TQM$/$Six Sigma quality control efforts, the number of models$/$styles comprising the company's product line, and the installation of production improvement upgrade option A$.$