Prepare an initial plan $(4$ marks$)$

$($b$)$ Prepare an alternative plan $(5$ marks$)$

$($c$)$ Which plan is better $($a$)$ or $($b$)?$ Why? $(2$ marks$)$

$($d$)$ How many units should be produced using overtime hours in the alternative plan?

What is the adequate timing for overtime production? Explain. $(4$ marks$).$