Table 8 Optimum and worst
levels based on summary statistic
of mean for power response
Control factors Levels
Optimum level/value Worst level/value
A. Bending angle concept A2 C10 A4 C20
B. Roller radius (R) (m) B1 0.1 B4 0.22
C. Line velocity (U) (m/s) C4 0.31 C1 0.1
D. Roll inter-distance (m) D1 0.48 D4 0.54
E. Roll gap (% of nominal thickness) E1 1 E4 3.1
Production rate (parts/min) 192.41 84.9
Total power input (W/m) 29.75 43.53
Energy efficiency indicator (m/J-h) 0.3283 0.046
No. of RS 10 6