f$.$ B and C

g$.$ A$,$ B$,$ and $C$

$11.$ Suppose in the order$-$up$-$to model the target in$-$stock probability is $\mathrm{.}95$ and demand across periods is independent and normally distributed. If the lead time is doubled but the target in$-$stock probabilitreses by more than a factor of $2).$

a$.$ It more than doubles $($itly by a factor of $2).$

b$.$ It doubles $($increases exactor of $2.$

c$.$ It increases but by less than afactor of

d$.$ It decreases.

e$.$ The answer cannot be determined with the given information.

L$014-4$

$12.$ A firm uses the order$-$up$-$to model to manage its inventory. It wants to increase its in$-$stock probability while decreasing its holding costs $($i$.$e$.,$ reducing its average inventory$).$ Which of the following actions will help to achieve this goal? $($Consider each action independently.$)$

A$.$ Decrease the lead time.

B$.$ Increase the order$-$up$-$to level.

C$.$ Increase the average quantity on order.

a$.$ Only A

b$.$ Only B

c$.$ Only C

d$.$ A and $B$

e$.$ A and $C$

f$.B$ and $C$

g$.$ Any of them will help $($i$.$e$.,$ A$,$ B$,$ or C$).$

h$.$ None of them will help.

$13.$ In the order$-$up$-$to model, assume that the mean of demand in a period remains the same and the target in$-$stock probability is kept at a constant level. If the demand uncertainty $($the standard deviation of demand in each period$)$ increases, then:

a$.$ expected on$-$hand inventory increases.

b$.$ expected on$-$hand inventory decreases.

c$.$ expected on$-$hand inventory remains the same.

d$.$ expected on$-$hand inventory may increase or decrease, depending on the demand dis$-$