Maximum Production Rate Criterion:

Maximum production rate means the time required to make each component should be minimum. The time per component for a single-pass turning operation is found by substituting Eqs. (8) and (9) in Eq. (5). Thus,

                             ------------- (21)

Assuming that T_l and T_d are lowest possible, the conditions for maximum production rate are evaluated as follows :

For optimum cutting speed,

                                   ∂T_t /∂V  = 0

Following the same procedure as in Section 10.3, solution of the above equation will result in

                                         ------------- (22)

Similarly, for optimum feed rate

                                ∂T_t/∂f   = 0

Solution of the above equation will result in

              ----------- (23)

Eqs. (22) and (23) cannot be satisfied simultaneously hence an unique minimum time per component (i.e., maximum production rate) does not exist. Eq. (10.22) is often presented in the form

                    . . . (24)

where, T_{v p} is the tool life for maximum production rate when speed is optimized. The tool life T_{v p} is found first and speed is found when the feed is selected. In the same say, T f_p using Eq. (23) can be evaluated.