The Action Toy Company has decided to manufacture a new train $?$ ?set, the production of which is broken into six steps. The demand for the train is $4800$ ?units per $?40-$ hour workweek: $$

Task $|$ ?A $-$ ?B $-$ ?C $-$ ?D $-$ ?E $-$ ?F

Performance Time $($ seconds $)|20-30-14-15-12-27$

Predecessors $|\_-$ ?A $-$ ?A $-$ ?A $-$ ?B $,$ C $-$ ?D $,$ E

?

This exercise only contains parts $?$ ?b $,$ ?c $,?$ ?d $,$ ?e $,$ ?and f $.$

Part $2$

$?$ b $)$ ?Given the $?$ ?demand, the cycle time for the production of the new train set $?=30$ ?seconds.

Part $3$

$?$ c $)$ ?The theoretical minimum number of workstations $=4?($ round your response up to the next whole $?$ ?number $).$

d $)$ ?Using the longest operation time $?$ ?rule, the assignment of tasks to workstations should $?$ ?be: $?($ Hint: Number workstations sequentially in terms of precedence relationships and combine any applicable $?$ ?tasks. $)$