OM 7011 Assignment 2 Summer 2014

Natural Blends case

Complete all questions in the case; show all calculations that accompany your logic and embed the spreadsheets that you develop in the Word document. This is a very long exercise so make sure you give yourself adequate time for it.

Chapter 6: Quality management

1. Open the attached spreadsheet titled Deming’s funnel experiment and concludes on the results of the four different responses to changes. What can you conclude from these results?

2. Question 18, page 192

3. Find and summarize at least 3 examples of Poka-yoke in services (see page 186 as well)

4. You are the plant manager of a company that makes the steel balls that are used in ball bearings. Your process is capable of producing balls with a 3-sigma process capability of ?0.0003", which is also the tolerance specified by your existing customers. Business is slow, but a new customer has offered to buy approximately 65-70% of your output if you can deliver balls with a tolerance of ?0.0001". You figure you can sell the remainder of your output to your existing customers. One of your employees suggests you try sorting the balls by size after they are made, by sifting them through a series of grates with appropriately sized openings. The ones within ?0.0001" will be shipped to the new customer, the ones within ?0.0003" are sent to your existing customers, and the remainders are scrapped.

a) Is this plan feasible? Can you deliver 65-70% of your output to the tolerance demanded by your new customer? Justify your answer.

b) What will be the expected scrap rate?

c) After a few months, both your new customer and your existing customers complain that bearings built with your balls do not run as smoothly as bearings built with balls produced in Japan, even though the specifications are the same. Explain why this might be the case.

5.Customer expectations on pizza delivery are such that most people are happy with a 20 minute delivery and very upset if it takes more than 40 minutes. You have observed the delivery time for a random sample of customers for two days as follows:

Day 1 2 3 4 5 6 7 8 9 10

1 15 23 22 28 34 10 55 20 37 41

2 32 23 27 40 12 48 45 22 35 31

a) Competition is really cut-throat and in an effort to improve service delivery quality, one proposal calls for disciplining and/or reprimanding the delivery person who takes more than 40 minutes for delivery. What do you think about the proposal?

b) What is the capability of the process? Is a control chart useful for this situation? Why or why not?

c) Suggest the upper and lower control limits of a control chart that would monitor the pizza delivery process?

d) How would you use the control chart?

e) Explain whether the following is true or false: It is impossible for a process to be in control if it does not meet customer specifications.

Chapter 7: Supply chain management

6. Question 10, page 225

7 Question 14 and 15, page 225

8. Question 17, page 225.

9. Find at least one example of a firm currently redesigning it’s supply chain and summarize the main arguments for the change in one paragraph.