OSC exam 1

Let's say you get an email or text every 5 minutes on average. It takes only 30 seconds to respond, so 6 minutes per hour in total for the answer itself. But every time you are interrupted to answer, it costs you 30 seconds of lost concentration. If you want to maximize the time you have to work on things other than email, what should you do?

"Batch" your emails/texts and only answer them once every hour or so.

Imagine a simple process in which 5 ticket booths are selling tickets for an opera. If customers are coming at a rate of 15 / hour, and the utilization of the 5 booths is 50%, then how long does a customer spend at a booth, aside from any waiting time (each customer goes to only one booth)?

10 min

same question as last answer (green iguana). what is the waiter's total time required to process the orders for the entire table?

170 seconds

A process operates for 10 hours a day. The process experiences demand of 1200 / day (meaning customers wish to purchase 1200 units per day). How many units does the process need to produce per operating minute in order to meet the demand?

2

Let's say a restaurant sells a meal for $20;spends 20% ($4) for the food ingredients;spends 40% ($8) for the labor directly involved in cooking and serving one meal;gets 60 customers per each of 30 days per month; andincurs monthly fixed costs of $12,000. What is the restaurant's monthly profit?

2,400, variable cost is ($4 + $8) (60/day) (30 days/mo) = $21,600. total sales is ($20/dish) (60 dishes/day) (30 days/mo) = $36,000/mo.Profit = $36,000 - $21,600 - $12,000 = $2,400

If it takes a clerk at a grocery store 5 minutes to check someone out on average, and a second clerk is added, then what is the capacity of the checkout function at the grocery store?

24 jobs per hour

If we say it takes 5 minutes to process a job at some given process stage, and then further say there are 2 resources at this process stage, we mean that it takes 5 minutes to process the job assuming only one of the resources works on the job. What is the total processing capacity at the stage described above?

24 jobs per hour

A party of 5 goes to the Green Iguana. The waiter takes 10 seconds to get from the kitchen to the table (or vice versa), and takes 30 seconds to manually take each person's order at the table. The waiter always starts in the kitchen, goes out to a table, takes the order for the batch (whatever the batch size), and then delivers the order for only that batch back to kitchen. If the waiter takes the table's orders in batches of 1 (only taking the order of 1 person), what is the waiter's total time required to process the orders for the entire table?

250 seconds

A pharmacy has two types of customers: those who are there to pick up a repeat prescription (this takes on average 1 minute), and those who are there to pick up a first-time prescription (this takes on average 6 minutes as it requires some explanation). On average 20 customers arrive per hour who want a repeat prescription, and also 20 who want a first-time prescription. How many employees should this pharmacy hire at the bare minimum?

3

In the Week 3 Process Flow video showing queueing, what was the average time in the queue for a job when the arrivals were variable (i.e., when the inter-arrival times were either 1 second, or 5 seconds, or 9 seconds)? You do NOT need to actually calculate anything or closely time anything to answer this question; just watch the video and think about what you saw. Only one answer will be reasonable.

3 seconds

At a Mexican fast-food chain, a customer a) decides what type of food s/he wants (e.g., burrito, salad, or tacos), b) decides what fillings s/he wants (e.g., chicken, fish, or vegetable), c) decides what toppings s/he wants (e.g., lettuce, guacamole, or cheese), and d) pays for the order that may or may not include a drink. One employee works at each of the steps a) through c), and two employees take care of the payment. Per customer, step a) takes 2 minutes on average, step b) takes 3 minutes on average, step c) takes 1 minute on average, and step d) takes 4 minutes on average. By how much would the system capacity increase if another person is hired for step b)?

50%

Stage 1 has a total capacity of 60 jobs per hour, and there are 3 processors at stage 1. Stage 2 has a total capacity of 60 jobs per hour and has 4 processors. How long will it take a job to get through the system, assuming there is no waiting time, and each job is processed by only one resource at each stage? Hint: just take the processing time at stage 1, and add it to the processing time at stage 2.

7 min

What is the output for a law firm?

A case that is resolved in some way (maybe it was dropped, or settlement achieve, or a court decision rendered)

What is the input for a hospital?

A sick or injured patient

What happens in a system in which the job arrival rate (R) exceeds the system capacity (m c)? (For example, a Professor sometimes comes across a student who represents such a system: the student is working full time, plus has responsibilities at home, plus is trying to take an overload of courses, plus pursues a social life.)

All are correct, The implied utilization will be greater than 100%, Eventually, either R will have to go down or (m c) will have to go up. For example, R goes down if some work just never gets done (the work effectively "reneges," leaving the system without getting processed). Or, for example, capacity is increased by "cutting corners" (i.e., by inappropriately reducing process time). Absent a reduction in R or an increase in (m c), jobs will "back up" (a queue will form), resulting in lateness (excessive throughput time for a job).

In going through life, you will continually face "bottlenecks" that constrain you from achieving your most-aggressive goals (whatever those goals may be). If you were to model good operations practice, how would you approach this issue?

All of the answers, Recognize that when you alleviate a bottleneck, another will likely (invariably?) materialize. Find (identify) the bottleneck. Figure out how how to alleviate the bottleneck.

What resource(s) does an airline use to create their output?

All of them, passengers, pilots, airports

According to the article "In Pursuit of Product Modularity...", what is an example of a product where most users have the same basic preferences in product features, but there is wide disparity in the need for updating of the various "pieces" of the product?

An inkjet printer

Numerous parties of size 5 go to the Green Iguana at random times. The Green Iguana employs 5 waiters. A waiter takes 10 seconds to get from the kitchen to the table (or vice versa), and takes 30 seconds to manually take each person's order at the table. A waiter always starts in the kitchen, goes out to a table, takes the order for the batch (whatever the batch size), and then delivers the order for only that batch back to kitchen. In which case will the implied utilization be higher for the waiters - for batch sizes of 5 where there is only one waiter per table who takes the order of all 5 people before going back to the kitchen, or for batch sizes of 1 where 5 waiters go to each table and each waiter takes the order of only 1 person and then delivers that order to the kitchen (and then the 5 waiters go take orders at the next table in similar fashion)?

Batch size 1

Which of these is associated in the TIRP article with a lack of transparency in the supply chain?

Bullwhip effect (e.g., swings in diaper demand at P&G)

Which of these is one of IDEO's reported mottos?

Fail often in order to succeed sooner

In the IDEO video, what was Dave Kelly's description of the process?

Focused chaos.

In the article "The Cost Conundrum," what was the conundrum?

Healthcare costs across two seemingly similar cities were vastly different

Consider a system with multiple stages, where one stage is the bottleneck. Let's say that the arrival rate (e.g., customers per hour) increases by 10%, keeping everything else the same. The stage that was the bottleneck:

Is then by definition still the bottleneck

We call your current set of BCOR courses an "integrated core." Does this mean that your undergraduate education is a fully-integral product and not a modular product?

It means that the BCOR curriculum is a platform (module) that is itself (internally) an integral design, but then this integral platform couples with a module representing the curriculum for your chosen major to collectively (at a "higher level") constitute a modular design.

Which of the following was the key explanation for the conundrum in "The Cost Conundrum" article?

Lack of incentive compatibility across the supply chain.

What is the cause of Double Marginalization?

Myopic profit maximization

Starting with the base case below, let's say a restaurant executes a successful marketing campaign and thereby increases its demand by 5%. The higher demand necessitates renting additional restaurant space and adding equipment and personnel, such that all costs go up by the corresponding 5% (both fixed costs and variable costs go up by 5%). Under these assumptions, does the demand increase yield the "multiplier effect" on profit similar to what we found for the 5% operational improvement?

No, the marketing campaign yielding a 5% increase in demand yields the same 5% increase in profit.

To "keep your options open," you might want to declare your major as late in the process as possible. In the context of our framework, this would be called:

Postponement

Which Project Management methodology is better-positioned to avoid a situation where late changes in customer needs necessitate delaying the entire project?

Scrum

If you reduce the number of processors at any given stage, the "highway analogy would be that you?

Shut down a lane of the highway.

Let's say you get an email or text every 5 minutes on average. It takes only 30 seconds to respond, so 6 minutes per hour in total for the answer itself. But every time you are interrupted to answer, it costs you 30 seconds of lost concentration (this lost concentration time is associated with the email task). What is the tradeoff you face in deciding whether to use a batch size of 1, or a larger batch size?

Smaller batch size increases utilization associated with the email task, but reduces the response time (also called lead time).

In a system with two subsequent stages, stage 1 has two processors, each with a capacity of 10 units per hour, and stage 2 has three processors, each with a capacity of 7 units per hour. Which of these two stages is the bottleneck?

Stage 1

If Apple switched from its current iPhone design to one where you could readily replace the battery and the camera and the processor, this would represent:

Switching from a more-integral design to a bit-more-modular design.

If you add a resource to a particular stage of a system, what happens to the bottleneck?

The bottleneck may or may not shift, depending on the capacities and numbers of the processors at each stage.

WIP (work-in-progress) is:

The name for the inputs that are not yet outputs

In scrum, the burndown chart plots:

The remaining process time versus elapsed time.

In the class discussion, which industry was used as an example of use of the waterfall method?

The skyscraper construction industry

Which of the following combinations does NOT have a utilization of 50%?

The system is a Doctor's office. Capacity = 5 per minute; Demand = 600 / hour.

What is a major difference between the scrum approach and the waterfall approach to project management?

The waterfall approach has one comprehensive product release whereas the scrum approach has multiple iterative releases.

IDEO is a firm that designs products. (If you haven't already seen it, below is a link to a video describing how they went about designing a new shopping cart.) Here is a quote from IDEO's founder, Dave Kelley: "The point is, we're not expects in any given area. We're expects on the process of how you design stuff. So we don't care if you give us a toothbrush, a tractor, a space shuttle, a chair, it's all the same to us." What does Dave Kelley mean by this?

They have found what they believe to be the best set of process steps for designing new products, and they methodically follow those process steps regardless of the type of product they are designing.

Hammon's is contemplating opening a little stand-alone satellite store. After a careful analysis, managers have concluded that 25 customers per hour will need to check out at the satellite store (this will be the long-run average demand at the store). They are considering hiring two cashiers, each of whom can check out a customer in 5 minutes on average. What can you say about this system? Hint: we'll refer to a system with utilization above 100% as being "unworkable;" for example you cannot work 25 hours per day.

This system will be unworkable. The managers at Hammon's need to do something.

Starting with the base case below, let's say a restaurant takes out non-value-adding process steps and thereby cuts direct labor time by 5%. (Coincidentally, workers are happier, however we don't factor that effect into our analysis here.) By how much does it increase its absolute profit? Same base case as question 5

Total sales = ($20/dish) (60 dishes/day) (30 days/mo) = $36,000/mo.Variable cost = [$4 + (0.95 x $8)] (60/day) (30 days/mo) = $20,880.Profit = $36,000 - $20,880 - $12,000 = $3,120. % increase in profit = ($3,120 - $2,400) / $2,400 = 30%

The Financial technology (fintech) industry might frequently do which of the following?

Use Scrum in conjunction with the modular/upgradeable products it develops.

In the IDEO video, when did someone "get the bell"?

When they criticized an idea in a brainstorming session.

In the IDEO video, what was said to have been clocked at 35 mph?

a shopping cart

Starting with the base case below, let's say a restaurant improves its inventory management practices and thereby reduces the variable cost of ingredients by 5%. By how much does it increase its absolute profit?

answer 15%, Total sales = ($20/dish) (60 dishes/day) (30 days/mo) = $36,000/mo. Variable cost = [(0.95 x $4) + $8] (60/day) (30 days/mo) = $21,240. Profit = $36,000 - $21,240 - $12,000 = $2,760. % increase in profit = ($2,760 - $2,400) / $2,400 = 15%

Starting with the base case below, let's say a restaurant implements a lean op's initiative such that it is able to increase capacity (the maximum throughput rate) by 5% without an increase in fixed costs (that is, variable cost per meal does not change but the number of meals sold increases by 5% but with no increase in fixed costs). Assuming the demand exists to take advantage of the 5% capacity boost, by how much does the restaurant increase its absolute profit? same base case

answer= 30%. The new revenue is $20 x (1.05 x 1800) = $37,800 while the new variable cost is $12 x (1.05 x 1800) = $22,680 and fixed costs remain at $12,000 yielding total costs of $34,680 and profit of $$3120 which is an increase of $720 which is 30% of $2400.

In the Week 3 Process Flow video showing queueing, how many jobs were in the server at any INSTANT in time? (If you just freeze the video at any point and count the number of jobs in the server, how many jobs are in the server at that instant?)

either zero or 1

According to the article "In Pursuit of Product Modularity...", what is an example of a product where users have disparate preferences in product features, and there is wide disparity in the need for updating of the various "pieces" of the product?

iphone software

What is the utilization of a typical city fire truck over the duration of 8760 hours in a year, considering only the primary function of a fire truck which is to fight fires within that city's boundaries (within its city limits)?

less than 25%

What is the utilization of one of the elevators in SFEBB averaged out over the entire day? (Reference the class discussion on this question.)

less than 25%

Which project management tool uses the analogy "skateboard-bicycle-motorcycle-car"?

scrum

According to the article "In Pursuit of Product Modularity...", what is an example of a product where users have disparate preferences in product features, but there is little disparity in the need for updating of the various "pieces" of the product?

the automibile

According to the article "In Pursuit of Product Modularity...", what is an example of a product where most users have the same basic preferences in product features, and there is little disparity in the need for updating of the various "pieces" of the product?

the iphone hardware

"Enlighted trial and error succeeds over the planning of _____" (fill in the blank, as per the IDEO video).

the lone genius.

Which project management tool did the Shopping Cart Project more-closely follow, in terms of product releases?

waterfall