Problem

For this week Problems activity, you will complete and submit the following items:

Chapter 7

· Problem 1

· Problem 6

· Problem 12 (Hint: Use Descriptive Statistics tool in the Excel Data Analysis menu)

· Problem 15 (Hint: Use the Taguchi Template)

· Problem 18

· Problem 24

· Problem 29

Note 1 : A few of the problems above will use the data sets found in C07Data.xlsx. In addition, the Excel Templates folder on the course home page contains 'templates' that will aid in solving a few of these problems.

Note 2 : In order to earn credit for your answers to the problems, you are required to show all supporting work . Also, you may be expected to use Microsoft Office applications (Excel, Word, and/or PowerPoint) when showing your supporting work. If you use a 'template', save all of the information (numerical/visual).

PROBLEMs

PROBLEM 1. A hospital developed a design process consisting of the following steps: Plan, Design, Measure, Assess, and Improve. Below is a list of specific activities that comprise these five steps in random order. Place the activities in the most appropriate order within the correct step of the design process.

Pilot or test design

Submit proposal

Define measures to assess design performance

Implement design

Identify potential solutions to reduce out of control conditions

Develop business plan

Disseminate improvements throughout the organization

Monitor process performance Select the best solution to improve control Identify out-of-control conditions Propose new concept Create design to meet requirements Identify new improvement opportunities Monitor the new process design Implement the best solution to improve control

Verify proposal alignment with strategic objectives

Establish design team Identify causes of out of control conditions Analyze causes Identify and validate customer requirements Identify and evaluate best practices

PROBLEM 6

A blueprint specification for the thickness of a refrigerator part at Lafrigeradora, Inc. is 0.040 ` 0.035 centimeters (cm). It costs $30 to scrap a part that is outside the specifications. Determine the Taguchi loss function for this situation.

PROBLEM 12

An automatic cookie machine at ACM, Inc. must deposit a specified amount of 25 ` 0.3 grams (g) of dough for each cookie on a conveyor belt. It costs $0.03 to scrap a defective cookie. A sample of 50 cookies was drawn from the production pro- cess, which has been determined to be approxi- mately normally distributed, and the results, in grams, can be found in worksheet tab Prob. 7-12 in the Excel file C07Data.

a. What is the value of k in the Taguchi loss function? b. Determine how much the process varies from the target specification, based on the mean difference and standard deviation of the Sample results. What is the expected loss per unit?

PROBLEM 15

At Elproparts Manufacturers’ integrated circuit

business, managers gathered data from a customer focus group and found that any output voltage that exceeds 60 ` 3.5 volts was unacceptable to the customer. Exceeding these limits results in an esti- mated loss of $90. However, the manufacturer can still adjust the voltage in the plant using a quick diagnostic test that costs $3.75.

a. Determine the Taguchi loss function. b. Suppose the nominal specification remains at 60 volts. At what tolerance should the integrated circuit be manufactured?

Problem 18

Massive Corporation’s tested five motors in a 900- hour test. Compute the failure rate if, three failed after 200, 475, and 750 hours (about 1 month) and the other two ran for the full 900 hours each.

PROBLEM 24

A manufacturer of MP3 players purchases major electronic components as modules. The reliability of components differ by supplier (see the system diagram below). Suppose that the configuration of

the major components is given by:

The components can be purchased from three different suppliers. The reliabilities of the components are as follows:

Component Supplier 1 Supplier 2 Supplier 3

A 0.98 0.96 0.95

B 0.95 0.97 0.98

C 0.99 0.96 0.94

Transportation and purchasing considerations require that only one supplier be chosen. Which one should be selected if the player is to have the highest possible reliability?

PROBLEM 29

CajaGigante, a large department store, has a very successful and profitable package-wrapping depart- ment. The department uses two complex bow- making machines that work inline to make the bows for the packages. There is one skilled operator who knows how to operate the machines. She had been very reliable, but recently has had increasing health problems which caused her to miss work about 10 percent of the time. Bow-making Machine 1 has a reliability of 0.97. Machine 2 has a reliability of 0.90.

a. What is the current reliability of the system, including the operator?

b. Management is considering either scrapping Machine 2 and replacing it with a new machine which has a reliability of 0.97 at a cost of $5,000, or training another operator to fill in when the first operator is absent at a cost of $5,100. The prospec- tive trainee has an excellent attendance record and has only been absent 4 days out of 250 work days for the department, last year. Management estimates that profits from the department would increase by $6,000 per year, if the bow- making line operated at 100 percent of capacity. If management wants to pay off its investment in the first year, determine the expected net profit for each alternative, and recommend which one will be the most profitable to management.