$5.$ Consider two different machines A and B that could be used at a station. Machine A has a

mean effective process time te of $1\mathrm{.}0$ hours and an SCV c$2$

e of $0\mathrm{.}25.$ Machine B has a mean

effective process time of $0\mathrm{.}85$ hour and an SCV of $4.($Hint: You may find a simple

spreadsheet helpful in making the calculations required to answer the following questions.$)$

$($a$)$ For an arrival rate of $0\mathrm{.}92$ job per hour with c$2$

a $=1,$ which machine will have a shorter

average cycle time?

$($b$)$ Now put two machines of type A at the station and double the arrival rate $($i$.$e$.,$ double

the capacity and the throughput$).$ What happens to cycle time? Do the same for machine

B$.$ Which type of machine produces shorter average cycle time?

$($c$)$ With only one machine at each station, let the arrival rate be $0\mathrm{.}95$ job per hour with

c$2$

a $=1.$ Recompute the average time spent at the stations for both machine A and

machine B$.$ Compare with $($a$).$

$($d$)$ Consider the station with one machine of type A$.$

$304$ Part II Factory Physics

i$.$ Let the arrival rate be $1$

$2$ job per hour. What is the average time spent at the station?

What happens to the average time spent at the station if the arrival rate is increased

by $1$ percent $($i$.$e$.,$ to $0\mathrm{.}505)?$ What percentage increase in wait time does this

represent?

ii$.$ Let the arrival rate be $0\mathrm{.}95$ job per hour. What is the average time spent at the

station? What happens to the average time spent at the station if the arrival rate is

increased by $1$ percent $($i$.$e$.,$ to $0\mathrm{.}9595)?$ What percentage increase in wait time does

this represent?