Consider $3$ machines in parallel with different speeds, $3$ jobs, preemptions are allowed and can only be made at the time points $0,4,8,12,$ and so on$.$ The makespan is the objective of this scheduling problem.

$\backslash$table$[[$Machine$,1,2,3],[$Speed$,2,3,1]]$

$\backslash$table$[[$Jobs$,1,2,3],[$pj$,36,34,12]]$