Define "crash priority" orders as those that must be completed as soon as possible $($no waiting or delay is allowed$).$ Will a crash priority order cause disruption to current order$($s$)$ that is$/$are already being processed in the following cases? $($Disruption means the progress of current orders is affected as they have to give way to the crash priority order.$)$ For simplicity, assume there is only one order currently in the process.

a$.$ The only current order is in the cooling stage;

b$.$ The only current order has been baked for $4$ minutes;

c$.$ The only current order just entered the oven;

d$.$ The only current order is in the mixing stage.

Define pending orders as all orders you have received but not finished yet $($some could be in the process already, while others are waiting to enter the process$).$ Suppose the number of pending orders is the only information you have $($i$.$e$.,$ you do not know the status

of any of the pending orders$)$ when someone calls in to place an order.

a$.$ Assume that the process is in a steady state. Given that you know the number of pending orders and the CT of the process, what is a VERY SIMPLE way for you to quickly estimate the time to complete the caller's order?

b$.$ Is this estimate always sufficient for you to complete his order? If not, how much more time should you add to the estimate so that you can certainly finish his order within this augmented estimate? $($Hint: the process may not be in a steady state when you receive the new order. Consider the worst$-$case scenario. Keep it simple, do NOT

consider any possible disruptions or burnt cookies.$)$Answer the following question. Draw a process flow diagram. Ignore step$($s$)$ whose time is negligible. Indicate in the diagram who $($Kristen or her roommate$)$ performs each task. Also draw a Gantt chart for at least $4$ complete orders.

How long will it take you to fill a rush order?

How many orders can you fill in a night, assuming you are open for $4$ hours each night? $($The whole production line is empty, i$.$e$.,$ there is no WIP, when you start the night. In other words, the process is not in a steady state when you start the night.$)$

How much of your own and your roommate's valuable time will it take to fill each order? Define valuable time as the productive time, i$.$e$.,$ it is the time when Kristen or her roommate is working on something.

Because your baking trays can hold exactly one dozen cookies, you will produce and sell cookies by the dozen. Let us now explore the impact of multi$-$dozen orders.

a$.$ For simplicity, consider a case where every order is $2$ dozen $($same flavor$).$ Does this change the cycle time of the whole process? Draw a Gantt chart for the case of $2-$ dozen orders $($complete at least $2$ orders, i$.$e$.,4$ dozen$).$

b$.$ Compared with two one$-$dozen orders, can a two$-$dozen order $($same flavor$)$ reduce the valuable time? If so$,$ how much is the reduction $($in minutes$)?$

c$.$ If a customer orders a dozen chocolate cookies and a dozen peanut cookies, would this two$-$dozen order affect the cycle time of the whole process? Is there any reduction in valuable time? If so$,$ how much?

Given that there is only one oven, how many mixers will you need? What is the minimum number of baking trays you need so that the process is not constrained by the trays?

$($Hint: for the baking tray question, use your Gantt chart to verify your answer $-$ but make sure your Gantt chart is drawn in a sensible way.$)$

What is the capacity of the process if another oven is added? Draw a Gantt chart to show what the new cycle time of the whole process is$.$ Also identify the MLT based on the Gantt chart you draw.

What is the bottleneck of the process?

$($Hint: the roommate can only do one activity at a time $-$ she cannot be packing and setting the timer concurrently. Also, make sure the CT and MLT based on your chart are consistent with your conclusions. For instance, you cannot claim CT is $x$ in your report while your Gantt

chart shows a CT of y$.)$

If you $($Kristen$)$ are trying to do this by yourself without a roommate, what is the impact on the capacity and MLT$?$ Draw a Gantt chart to illustrate the new process cycle time, and identify the bottleneck of the process. $($Hint: when drawing the Gantt chart, keep in mind that Kristen can only do one activity at a time$)$