Problem #$3$: Use Johnson's rule, develop a processing sequence and calculate the minimum makespan for the jobs given in Table $3.$

Table $3$: Details of Processing Times

Job

P

Q

R

S

T

Time on Processor $1($hours$)$

$5$

$5$

$9$

$3$

$10$

Time on Processor $2($hours$)$

$3$

$8$

$5$

$4$

$7$

At what hour was job Q finished on machine $2?$

At what hour was job T started on machine $2?$

What was the amount of idle time on machine $2$ between the completion of job Q and starting of job T$?$

At what hour was job T finished on machine $2?$

At what hour was job R started on machine $2?$

What is the total amount of idle time on machine $2?($Hint: You need to look at the complete schedule and identify idle time slots and add them up$)$