Q.The time interval between starting the first job and completing the last job including the idle time (if any) in a particular order by the given set of machines is called _______.

A sequencing problem fixes the jobs and their machine route and asks only for the order of jobs that minimises total elapsed time and idle time. For $n$ jobs on two machines ($M_1$ then $M_2$), Johnson's rule is optimal: repeatedly pick the smallest processing time — if it is on $M_1$ place that job earliest, if on $M_2$ place it latest — working inwards. For $n$ jobs on three machines ($M_1 \to M_2 \to M_3$), if $\min A_i \ge \max B_i$ or $\min C_i \ge \max B_i$, define $G_i = A_i + B_i$ and $H_ …