Q&A Hero

Q: All forecasts should include two estimates: an estimate of the demand and an estimate of the forecasting error.

Q: Which of the following regarding linear regression is correct? A. Linear regression is a form of exponential smoothing. B. Linear regression is the most commonly used qualitative method. C. Linear regression requires use of an independent variable to make estimates. D. None of the above are correct.

Q: Which of the following is NOT one of the important points to remember about collaborative planning, forecasting, and replenishment (CPFR)? A. Any organization entering into a CPFR arrangement must expect to pay for the benefits received. B. Sensitive information is not shared among partners, so proprietary information is not a factor in CPFR arrangements. C. Ongoing management attention will be needed to maintain a long-term CPFR relationship with another organization. D.All are important considerations for CPFR arrangements.

Q: Which of the following best describes the MAPE measure of forecast error? A. Calculate the deviation between the forecast and the actual value for each period. Divide each deviation by the level of demand. Take the absolute value of each deviation, sum all values, and multiply by 100. Divide by the number of forecast errors. B. Calculate the absolute value of the deviation of the forecast from the actual value for all periods. Sum all of the absolute values of the deviations and divide by the number of forecast errors. C. Calculate the difference between the forecasted value and the actual value for all periods. Square each of the differences. Sum all of the squared differences and divide by the number of differences. D.Calculate the difference between the forecast and the actual value for all periods. Sequentially sum up the forecast errors.

Q: A sports equipment retailer needs to forecast sales by product classes one to two years out. Which forecasting model is most appropriate? A. Moving average model. B. Weighted moving average model. C. Informed judgment. D. Econometric model.

Q: The life cycles analogy technique fits best with which of the following applications? A. A retailer wants to develop an overall sales forecast for the coming summer season. B. A cereal manufacturer has to decide how much new plant capacity will be required if it enters a new product category. C. A parts distribution business needs to create a workforce plan for the remainder of the year. D. A fishing lure manufacturer has to decide whether to invest in higher-capacity equipment this year to be ready for the next seasons demand.

Q: A qualitative forecast would be most likely used for A. aggregate planning. B. production scheduling. C. inventory management. D. facilities expansion.

Q: Which of the following is NOT a measure of variance in the forecast error? A. CFE (cumulative forecast error). B. MAD (mean absolute deviation). C. MAPE (mean absolute percentage errors). D. All of the above are measures of variance.

Q: Which of the following is likely to reveal a bias effect resulting from the forecast method in use? A. MSE (mean squared error). B. CFE (cumulative forecast error). C. MAD (mean absolute deviation). D. None of the above.

Q: Measured by the mean absolute deviation, which of the forecast methods (1, 2, or 3) provides the highest degree of forecast accuracy for the five weeks of data shown below? Week Demand Method 1 Method 2 Method 3 1 24 23 26 21 2 19 25 22 20 3 27 21 23 23 4 25 30 29 22 5 31 25 32 28 A. Method 1. B. Method 2. C. Method 3. D. Methods 1 and 2 are equal. E. Methods 2 and 3 are equal.

Q: 35.Assume you discovered from historical records that simple linear regression is an effective means of predicting the labor cost of some project tasks. You found that the weight associated with an item (in pounds) produced in historical projects is an accurate and reliable predictor of labor cost. You develop a linear equation expressing the relationship between item weight and labor cost: estimated demand = 1,300 + 0.25x For an upcoming project that includes the task of manufacturing an item weighing 7,000 pounds, estimate the task cost using this regression equation. A. $1,750 B. $3,000 C. $3,050 D. None of the above are correct.

Q: Using a three-period weighted moving average model with weights of W1 = 0.5, W2 = 0.4, and W3 = 0.1, what is the forecast of demand for week 6 using the same demand information from Problem 32? A. 23.10 B. 28.10 C. 28.50 D. 28.67

Q: Using a simple three-period moving average forecast model, what is the forecast of demand for week 6 given the historical demand levels shown below? Week Demand 1 24 2 19 3 30 4 25 5 31 A. 24.33 units B. 27.67 units C. 28.67 units D. 29.2 units

Q: When selecting a forecasting method, which of the following is true? A. The method with the best fit to historical data (least error) is the best predictive model. B. The existence of complicated data patterns will affect the method chosen. C. Stable data patterns over time are best suited to qualitative methods. D. Time series methods use qualitative data to smooth the forecasts.

Q: The exponential smoothing forecasting technique slowly responds to changes in the mean level of demand when A. a small alpha value is used. B. a large alpha value is used. C. an alpha value of 1.0 is used. D. size of the alpha value does not affect the responsiveness.

Q: The moving average forecasting technique rapidly responds to changes in the mean level of demand when A. a small number of periods is used. B. a large number of periods is used. C. an infinite number of periods is used. D. the number of periods used does not affect the responsiveness.

Q: The major components (patterns) of a time series consist of all of the following EXCEPT A. trend. B. seasonality. C. random error. D. correlation.

Q: Which of the following is INCORRECT about a qualitative approach to forecasting? A. Can include managerial judgment when developing forecast data. B. Is useful when past data are not good indicators of future conditions. C. Typically used for short-range forecasting decisions. D. A market survey is one example method.

Q: Which of the following is NOT a qualitative approach to forecasting? A. Market survey B. Life cycle analogy C. Informed judgment D. Box-Jenkins method

Q: Which of the following statements about forecasting is NOT correct? A. Forecasts should have at least two numbers: one for the best estimate of demand and the other a measurement of forecasting error. B. There is no universal forecasting method for all situations. C. Forecasts of sales and demand will always be equal. D.Forecasting is both an art and a science.

Q: Given the following weekly demand figures, what is the MAD at the end of week 5? A.10.8 B.11.8 C.12.0 D.13.0

Q: Which of the following is NOT true about collaborative planning, forecasting, and replenishment (CPFR)? A.The basic idea is to share forecasting information with the suppliers and customers in the supply chain. B.It is best applied to business-to-business relationships. C.It creates visibility in the supply chain, minimizing the occurrence of the bullwhip in supply chains. D.It requires advanced forecasting tools such as Box-Jenkins to improve the forecasting accuracy.

Q: _____ models are usually more accurate than ______ models for medium-to-long-range forecasts. A.Time series, causal B.Causal, time series C.Time series, qualitative D.Qualitative, time series

Q: Which of the following is NOT one of the most important factors in selecting a forecasting method? A.Nature of the decision. B.Patterns seen in the data. C.Data availability. D.Customer preferences.

Q: A method of forecasting that best describes the flows from one sector of the economy to another is called A.regression. B.econometric model. C.input-output model. D.simulation model.

Q: List and explain the five steps of the DMAIC process.

Q: Name the seven tools of quality control typically used in process improvement. Could all of these tools be applied to service operations? Suggest some possible service operations scenarios wherein we could apply all or some of these tools.

Q: Surveys indicate that p charts are used more frequently than average (mean) and range charts are used.

Q: Lean projects are usually simpler than six sigma projects.

Q: The quality tool that shows the relationship between two variables is a histogram.

Q: There are two indicators of a process shiftpoints outside the control limits and an upward or downward trend in the process average.

Q: If failure costs were very high, a company would still use inspection.

Q: Lean is another term for six sigma process improvement.

Q: Six sigma projects are typically managed by workers certified as black belts.

Q: Six sigma efforts are aimed at eliminating waste.

Q: In process capability analysis, the standard deviation (s) refers to the standard deviation of sample measures.

Q: The seven tools of quality control are equally applicable to both manufacturing and service industries.

Q: The Cp measure requires the process to be centered for an accurate measure of process capability.

Q: The central tendency (mean) of the process is the only information needed to determine if the process is in a state of control.

Q: Attribute control occurs when the product characteristic is measured on a continuous scale.

Q: A production process delivers an unexpectedly large amount of scrap products. Top management has discovered that improper machine maintenance is the reason behind this failure. The above statement is an example of a special cause of variation.

Q: Which of the following statements is NOT correct? A.Six sigma projects require measurement of financial impact be closely tracked, compared to lean projects that do not insist on financial tracking. B. Six sigma relies more on dedicated experts to guide projects as compared to lean. C.Lean projects tend to be smaller and simpler compared to six sigma projects. D.Lean projects tend to support strategic priorities more than is the case for six sigma projects.

Q: A brewer bottles beer labeled net weight 12 ounces. A production employee pulled 20 random samples of 5 bottles each throughout the day and found that the average weight is exactly 12 ounces and the average range of the samples is 0.25 ounce. What is the lower control limit for the averages chart for this process? A.12.144 ounces. B. 11.955 ounces. C.11.856 ounces. D.None of the above.

Q: Which of the following statements is true? A. For a variables control chart, n should be fairly large, frequently 50300 observations. B. For an attribute control chart, n is typically 510 observations, and rarely larger than 24. C. For an attribute control chart, n should be large enough to include at least one defective unit. D. None of the above.

Q: Which statement best represents the key assumption(s) of process control? A.Most processes are affected by common and special causes of variation. B. It is easier to address common cause variation than special cause variation. C.Most processes are found to be in control. D.All of the above.

Q: Which of the following makes the most sense, given todays view of quality control? A.Full-time, certified inspectors are preferred for all critical control points. B. The department receiving the inputs is the preferred location for the critical control point. C. The person doing the job should have the responsibility of inspection. D.The manager of the process should be inspecting quality at critical points.

Q: The work of 20 claims processors is sampled and examined for errors. 100 claims are randomly pulled for each processor with the results shown below. What is the upper limit of the control chart? Sample # Errors Sample # Errors 1 6 11 6 2 5 12 1 3 0 13 8 4 1 14 7 5 4 15 5 6 2 16 4 7 5 17 11 8 3 18 3 9 3 19 0 10 2 20 4 Total errors: 80 A.0.059 (or 0.06). B. 0.084 (or 0.08). C.0.099 (or 0.10). D.None of the above.

Q: Consider the following statements: (1) The primary focus of lean is to reduce waste. (2) The primary focus of six sigma is to reduce defects. A.Only statement (1) is correct. B. Only statement (2) is correct. C.Both statements are correct. D.Neither statement is correct.

Q: Which of the following is the best description of variables data? A.Number of students more than six feet tall in a classroom. B. Ratio of damaged apples to perfect apples in a shipment. C.Downward force required to cause a critical part to fail during a quality test. D.Adequate strength of adhesive applied between two components.

Q: Which of the following statements is NOT correct? A.Control limits represent the voice of the process. B. The average of the measurement data collected is the same as the center line. C.Six sigma equates to 99.74% of output within the control limits. D.A normal distribution of a process under control will include a very small amount outside the control limits.

Q: Put the following statements in the correct order: (1) Decide who should do the inspection. (2) Decide on the type of measurement. (3) Decide on the amount of inspection. (4) Decide on the critical points requiring inspection. A.4, 1, 2, 3. B. 4, 2, 3, 1. C.1, 2, 3, 4. D.2, 4, 1, 3.

Q: Which of the following is the best description of quality control? A.The use of mass inspection in a process to ensure quality and meet customer requirements. B. The continuous improvement of a process to better address customer needs. C.The stabilization and maintenance of a process to produce consistent output. D.Constancy of purpose toward improvement of the product or service.

Q: Which of the following statements about six sigma is NOT correct? A.The six sigma approach is suited only for manufacturing processes. B. Six sigma programs employ full-time specialists called black belts. C.Six sigma employs a structured process improvement technique. D.Data and metrics are vital in a six sigma approach.

Q: The seven tools of quality control include all of the following EXCEPT A.flowcharts. B. Pareto charts. C.DMAIC charts. D.scatter diagrams.

Q: A manufacturer of television wall mounts would like to make a chart to monitor the percentage of defective mounting brackets due to problems with drilled holes. These holes may be defective because they are off-center, out of round, or not drilled. Five samples, each of size 100, have been taken from the production process and the discrepancies are as follows: Sample Percentage Defective 1 2.0 2 7.0 3 5.0 4 3.0 5 4.0 Using this information and a 3 standard deviation chart, the upper control limit is A.0.0025. B. 0.0420. C.0.0602. D.0.102.

Q: One of the first stages in any statistical process control program is to ascertain that the equipment utilized for an operation is inherently capable of producing within the design tolerance. For a particular lathe operation, run under controlled conditions so that no assignable causes of variation have been introduced, the outside diameter of each sampled part was measured, and the operator found that the standard deviation was 0.0075 centimeters (cm). What is the process capability if the upper specification limit is 7.508 cm and the lower specification limit is 7.388 cm? A.2.67 B. 1.00 C.0.375 D.None of the above.

Q: Range charts are used to evaluate A.the variability of data within samples for variable data. B. the variability of data within samples for attribute data. C.the variability of data among (central tendency) samples. D.the variability of process capability.

Q: __________ are ideal for monitoring continuous data. A.p-charts B. x-bar and R-charts C.Ishikawa charts D.None of the above

Q: If the population of items produced does not meet or exceed the upper and low specification limits (all items produced are well within specification limits), the process capability index, Cp, will be A.less than 0.0. B. between 0.0 and 1.0. C.equal to 1.0. D.greater than 1.0.

Q: The figure shown below represents a control chart determined from attribute data. Given this chart and the plotted observations, the most appropriate action would be A.take immediate action to identify potential causes of the variation. B. decrease the confidence interval for the control chart. C.do nothing because the process appears to be operating in control. D.increase the confidence interval for the control chart.

Q: While monitoring a production process that is in a state of statistical control, a control chart that uses a large confidence interval compared to one that uses a small confidence interval will A.classify a process as out of control more frequently. B. classify a process as in control more frequently. C.both A and B. D.neither A or B.

Q: Regarding the design of a quality control system, which of the following statements is correct? A.First, decide on the type of measurement required, then who will collect the data. B. First, decide on the amount of inspection needed, then critical points and type of measurement needed. C.First, decide who will be the inspector, then that person determines the critical points and collects the data. D.Decide on the critical points first, then the type and amount of measurement needed.

Q: Generally, two types of data may be collected from sampling at an inspection point. These two types of data are A.variable and attribute data. B. variable and conditional data. C.constant and attribute data. D.constant and conditional data.

Q: Which of the following is a critical inspection point where inspection and testing of products occur in a quality control system? A.Just prior to an irreversible operation (such as drilling). B. Just prior to a masking operation (an operation that may hide a defect, such as painting or plating). C.Just prior to packaging and shipping a finished product. D.All of the above.

Q: A machining process is capable of producing a component with an average specification of 5 inches and a process standard deviation of 0.1 inch. Supposing the customer accepts the component as long as it falls between 4.8 inches and 5.2 inches, then the process capability is A.1.333. B.1.5. C.0.667. D.1.0.

Q: A process for filling liquid laundry detergent bottles monitors the volume in each bottle. The operations manager has taken 5 samples with 4 observations (bottles) in each sample to determine if the variation in volume is reasonable. The measurement unit is fluid ounces. Calculate the center line for a process control chart that indicates whether the variation within samples is reasonable (in a state of control). Bottle Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 1 11.8 12.0 11.8 11.9 10.7 2 12.1 12.0 11.8 12.0 11.2 3 12.0 11.9 11.9 11.8 11.9 4 12.2 11.8 11.7 11.9 11.7 A.>1.0. B.Between 0 and 1.0. C.Less than 0. D.There is not enough information to determine the correct response.

Q: The chair of the Quality Department at Motorola University wants to construct a p-chart for determining whether the four faculty members teaching the course are in a state of control concerning the number of students who fail in the course. Accordingly, the chair sampled 500 final grades from last year for each instructor, and computed the number of failures per instructor as 13, 11, 0, and 16 respectively. Compute the upper and lower standard control limits for this chart. A.0.9500 and 0.0500. B.0.0600 and 0.1400. C.0.0388 and 0.0012. D.None of the above.

Q: Which of the following statements is NOT true about six sigma quality? A.Six sigma results in 3.4 ppm defects. B.Six sigma corresponds to 3 standard deviations on either side of the mean. C.Six sigma can be applied to administrative and service processes as well. D.Motorola invented the term "six sigma quality" in the mid-1980s.

Q: The ability of the process to meet, or exceed, its specifications can be determined by A.Pareto charts. B.cause-and-effect diagrams. C.histograms. D.Cp index.

Q: Which of the following techniques are used for continuous improvement? A.Pareto charts. B.Cause-and-effect diagrams. C.Process control charts. D.All of the above

Q: For which of the following would a p-chart be used? A.Monitor dispersion in sample data. B.Measure the number of defects per unit. C.Measure the central tendency. D.Measure the fraction defective.

Q: Which of the following quality control sample statistics indicates a quality characteristic that is an attribute? A.Mean B.Proportion C.Variance D.Standard deviation

Q: Which of the following is/are assumption(s) of process control? A.Random variability cannot be eliminated unless the process is redesigned. B.Common causes represent random variability. C.Production processes are not usually found in a state of control. D.All of the above.

Q: The appearance of a restaurant meal that is not satisfactory is an example of A.variable measurement. B.mean chart. C.range chart. D.attribute measurement. E.none of the above.

Q: Of the four choices below, which is the earliest step in designing a quality control system? A.The amount of inspection to use. B.Who should do the inspection. C.The type of measurement to be used. D.Training workers to perform inspection of their own work.

Q: Using the same data as in Question 10, what is the lower control limit for a p-chart? A..0750 B..0191 C..0000 D..0692

Q: Suppose that you have taken 30 samples of 200 units each and calculated the proportion defective as p = .075. What is the upper control limit for a p-chart? A..2192 B..0191 C..1309 D..7500

Q: Using the information from Question 8, what is the upper control limit for the range chart? A.57.7 lbs B.211.5 lbs C.317.25 lbs D.86.55 lbs

Q: Suppose that a process is in a state of control and we have the following information for a human weights measurement study: Average weight of males in the study = 150 lbs. Average range of the male weights = 100 lbs. A2 = .577 D3 = 0 D4 = 2.115 What is the upper control limit for the average (mean) chart? A.207.7 lbs B.92.3 lbs C.361.5 lbs D.175 lbs

Q: Which of the following statements about process capability is accurate? A.Cpk is a better measure of process capability than Cp. B.Cp is exactly equal to Cpk when the mean is centered in the specification limits. C.Given the same process, Cpk is always less than or equal to Cp. D.All of the above are accurate.