The primary problem associated with a process$-$focus layout $($e$.$g$.,$ job shop$)$ decision is

a$.$

dictated to large extent by scheduling considerations.

b$.$

to achieve equal distribution of work between work centers in order to maintain high efficiency.

c$.$

to be able to bring all necessary resources to a single location.

d$.$

to find the relative location of processing centers to achieve a stated objective within certain constraints.