EBK OPERATIONS MANAGEMENT
13th Edition
ISBN: 8220103675987
Author: Stevenson
Publisher: YUZU
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Chapter 3, Problem 30P
The classified department of a monthly magazine has used a combination of quantitative and qualitative methods to
a. Compute a tracking signal for months 11 through 20. Compute an initial value of MAD for month 11, and then update it for each month using exponential smoothing with α = .1 What can you conclude? Assume limits of ± 4.
b. Using the first half of the data, construct a control chart with 2s limits. What can you conclude?
c. Plot the last 10 errors on the control chart. Are the errors random? What is the implication of this?
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The following data are for calculator sales in units at an electronics store over the past nine weeks:
Week
1
2
3
4
5
Obtain the error measures. (Enter your responses rounded to two decimal places.)
CFE
MSE
Sales
Find the coefficient of determination (²).
The coefficient of determination r² = 0. (Enter your response rounded to two decimal places.)
44459
46
51
58
Use trend projection with regression to forecast sales for weeks 10-13. What are the error measures (CFE, MSE, 6, MAD, and MAPE) for this forecasting procedure? How about r²?
Obtain the trend projection with regression forecast for weeks 10-13. (Enter your responses rounded to two decimal places.)
Forecast, Ft
Period
10
11
12
13
Week
6
69809
7
Sales
54
63
53
61
MAD
U
MAPE
%
The following table gives the number of pints of type A blood used at Damascus Hospital in the past 6 weeks:
a) The forecasted demand for the week of October 12 using a 3-week moving average =
Week Of
August 31
September 7
September 14
September 21
September 28
October 5
pints (round your response to two decimal places).
Pints Used
345
389
408
381
371
374
The following table gives the number of pints of type A blood used at Damascus Hospital in the past 6 weeks:
Week Of
August 31
September 7
September 14
September 21
September 28
October 5
Pints Used
350
370
410
381
371
378
a) The forecasted demand for the week of October 12 using a 3-week moving average = 376.67 pints (round your
response to two decimal places).
b) Using a 3-week weighted moving average, with weights of 0.20, 0.35, and 0.45, using 0.45 for the most
recent week, the forecasted demand for the week of October 12 =
pints (round your response to two decimal
places and remember to use the weights in appropriate order the largest weight applies to most recent period and
smallest weight applies to oldest period.)
Chapter 3 Solutions
EBK OPERATIONS MANAGEMENT
Ch. 3.15 - Prob. 1.1RQCh. 3.15 - Prob. 1.2RQCh. 3.15 - Prob. 1.3RQCh. 3 - What are the main advantage that quantitative...Ch. 3 - What are some of the consequences of poor...Ch. 3 - List the specific weaknesses of each of these...Ch. 3 - Forecasts are generally wrong a. Why are forecasts...Ch. 3 - What is the purpose of establishing control limits...Ch. 3 - What factors would you consider in deciding...Ch. 3 - Contrast the use of MAD and MSE in evaluating...
Ch. 3 - What advantages as a forecasting tool does...Ch. 3 - How does the number of periods in a moving average...Ch. 3 - What factors enter into the choice of a value for...Ch. 3 - Prob. 11DRQCh. 3 - Explain how using a centered moving average with a...Ch. 3 - Contrast the terms sales and demand.Ch. 3 - Contrast the reactive and proactive approaches to...Ch. 3 - Explain how flexibility in production systems...Ch. 3 - How is forecasting in the context of a supply...Ch. 3 - Which type of forecasting approach, qualitative or...Ch. 3 - Prob. 18DRQCh. 3 - Choose the type of forecasting technique (survey,...Ch. 3 - Explain the trade-off between responsiveness and...Ch. 3 - Who needs to be involved in preparing forecasts?Ch. 3 - How has technology had an impact on forecasting?Ch. 3 - It has been said that forecasting using...Ch. 3 - What capability would an organization have to have...Ch. 3 - When a new business is started, or a patent idea...Ch. 3 - Discuss how you would manage a poor forecast.Ch. 3 - Omar has beard from some of his customers that...Ch. 3 - Give three examples of unethical conduct involving...Ch. 3 - A commercial baker, has recorded sales (in dozens)...Ch. 3 - National Scan, Inc., sells radio frequency...Ch. 3 - A dry cleaner uses exponential smoothing to...Ch. 3 - An electrical contractors records during the last...Ch. 3 - A cosmetics manufacturer s marketing department...Ch. 3 - Prob. 6PCh. 3 - Freight car loadings ova a 12-year period at a...Ch. 3 - Air travel on Mountain Airline for the past 18...Ch. 3 - a. Obtain the linear trend equation for the...Ch. 3 - After plotting demand for four periods, an...Ch. 3 - A manager of a store that sells and installs spas...Ch. 3 - The following equation summarizes the trend...Ch. 3 - Compute seasonal relatives for this data the SA...Ch. 3 - A tourist center is open on weekends (Friday,...Ch. 3 - The manager of a fashionable restaurant open...Ch. 3 - Obtain estimates of daily relatives for the number...Ch. 3 - A pharmacist has been monitoring sales of 2...Ch. 3 - New car sales for a dealer in Cook County,...Ch. 3 - The following table shows a tool and die companys...Ch. 3 - An analyst must decide between two different...Ch. 3 - Two different forecasting techniques (F1 and F2)...Ch. 3 - Two independent methods of forecasting based on...Ch. 3 - Long-Life Insurance has developed a linear model...Ch. 3 - Timely Transport provides local delivery service...Ch. 3 - The manager of a seafood restaurant was asked to...Ch. 3 - The following data were collected during a study...Ch. 3 - Lovely Lawns Inc., intends to use sales of lawn...Ch. 3 - The manager of a travel agency has been using a...Ch. 3 - Refer to the data in problem 22 a. Compute a...Ch. 3 - The classified department of a monthly magazine...Ch. 3 - A textbook publishing company has compiled data on...Ch. 3 - A manager has just receded an valuation from an...Ch. 3 - A manager uses this equation to predict demand for...Ch. 3 - A manager uses a trend equation plus quarterly...Ch. 3 - ML MANUFACTURING ML Manufacturing makes various...Ch. 3 - ML MANUFACTURING ML Manufacturing makes various...Ch. 3 - HIGHLINE FINANCIAL SERVICES, LTD. Highline...
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