Alright so, this is a qualitative question, there is really no number here

that you could crunch into the waiting time formula.

Nevertheless, I think it's helpful to remind ourselves of the waiting time

formula. Tq is equals to P divided by m.

Utilization raise to the 2m+1 minus one divided by one minus u times CVa squared

plus CVp squared divided by two. Alright, now let's look at the suggestions

that I put up here of adding more servers. So, adding more servers is a good idear,

right? You notice a larger m here will decrease

Tq. Now I want to be careful here in reminding you that the utilization, which

we defined as flow rate divided by capacity, and as one over the

inter-arrival time times m over P and then P divided by a times m, I want to just

emphasize that the utilization is also a function of m and so if you're taking the

sensitivity analysis derivative of Tq with respect to m, you cannot just look at this

term. Also u is changing as you're adding

servers, but, either way, adding servers is a good thing.

It will shorten the waiting time, Decreases service coefficient of

variation, That one is fairly straightforward.

You see the marginal impact here. Cvp shows up just linearly in here, and

everything that you do to CVp will be reducing the wait time, so this one also

makes sense. Decreasing the average service time.

You see this will help through P here in the formula.

That same comment is on mP, is also sitting in u, and will also have an x3

effect by allowing you to operate at a lower level of utilization.

And so, that one is certainly true as well.

Now, the last one, option D, is a little tricky here.

Leveling the demand. Why would that matter, and how do you

think about that? For that place, remember that if you plot

the time and the cube as a function of the utilization u, you have this very steep,

nonlinear effect. And so right now, in the morning hours, we

have a very high level of utilization. So, say, say, we are, we are here, high

level of utilization. And in the afternoon hours, we have a low

level of utilization. Now, conceptually, you see that if we

could now bring this together, and level the demand,

So we move some of the demand from the morning into the afternoon hours,

Well, the folks who had previously a super short wait time, well, they will lose a

little. They wait a little longer here, right?

So, you see, there's a little increase here in the waiting time, for these guys.

But the morning people with really, really benefit, right?

And so, you notice that, on average, it's nice to actually have a constant level of

utilization as opposed to having half of the customers get really high level of

utilization, and half of the customers having a really low level of utilization.

So, leveling the demand because of these convexities, of steep increase of the

waiting time as a function of u will be a good thing.

And thus, we can check option E, all, all of the above.