1. List the elements of a good forecast.
-The forecast should be timely.
-The forecast should be accurate.
-The forecast should be reliable.
-The forecast should be expressed in meaningful units.
-The forecast should be in writing.
-The forecast technique should be simple to understand and use.
-The forecast should be cost-effective: The benefits should outweigh the costs.
2. Outline the steps in the forecasting process.
-1. Determine the purpose of the forecast.
2. Establish a time horizon.
3. Select a forecasting technique.
4. Gather and analyze relevant data.
5. Make a forecast.
6. Monitor the forecast.
3. Describe at least three qualitative forecasting techniques and the advantages and disadvantages of each.
-Executive opinions: A small group of upper-level managers may meet and collectively develop a forecast.� It has the advantage of bringing together the considerable knowledge and talents of various managers.� However, there is a risk that the view of one person will prevail, and the possibility that diffusing responsibility for the forecast over the entire group may result in less pressure to produce a good forecast.
Salesforce opinions: The sales staff or the customer service staff is often a good source of information because of their direct contact with consumers.� They are often aware of any plans the customers may be considering for the future.� One disadvantage is that they may be unable to distinguish between what the customers would like to do and what they actually will do.� Another is that these people are sometimes overly influenced by recent experiences.� In addition, if forecasts are used to establish sales quotas, there will be a conflict of interest because it is to the salesperson�s advantage to provide low sales estimates.
Consumer Surveys: Since it is the consumers who ultimately determine demand, it seems natural to solicit input from them.� The obvious advantage of consumer surveys is that they can tap information that might not be available elsewhere. Disadvantages: A considerable amount of knowledge and skill is required to construct a survey, administer it, and interpret the results for valid information.� Surveys can be expensive and time consuming.
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4. Compare and contrast qualitative and quantitative approaches to forecasting.
-Qualitative methods consist mainly of subjective inputs, which often defy precise numerical description.� Quantitative methods involve either the projection of historical data or the development of associative models that attempt to utilize causal variables to make a forecast.� Qualitative techniques permit inclusion of soft (human opinions & hunches) information in the forecasting process.� Those factors are often omitted or downplayed when quantitative techniques are used because they are difficult to quantify.� Quantitative techniques consist mainly of analyzing objective, or hard, data.� They usually avoid personal biases that sometimes contaminate qualitative methods.�
5. Briefly describe averaging techniques, trend and seasonal techniques, and regression analysis, and solve typical problems.
Averaging techniques smooth fluctuations in a time series because the individual highs and lows in the data offset each other when they are combined into an average.� A forecast based on an average thus tends to exhibit less variability than the original data.� This can be advantageous because many of these movements merely reflect random variability rather than a true change in the series.
6. Describe two measures of forecast accuracy.
-� Three commonly used measures for summarizing historical errors are the mean absolute deviation (MAD), the mean squared error (MSE), and the mean absolute percent error (MAPE).� mean absolute deviation (MAD) is the average absolute forecast error.� mean squared error (MSE) is the average of squared forecast errors.� mean absolute percent error (MAPE)� is the average absolute percent error.
7. Describe two ways of evaluating and controlling forecasts.
-A control chart is a visual tool for monitoring forecast errors.� In order for the forecast errors to be judged �in control�, two things must happen.� One is that all errors are within the control limits.� The other is that no patterns, trends, and cycles are present.� A tracking signal is the ratio of cumulative forecast error to the corresponding value of MAD used to monitor a forecast.� It relates the cumulative forecast error to the average absolute error.� The intent is to detect any bias in errors over time.
8. Identify the major factors to consider when choosing a forecasting technique.
- The two most important factors are cost and accuracy.� Other factors to consider in selecting a forecasting technique include the availability of historical data: the availability of computer software: the ability of decision makers to utilize certain techniques: the time needed to gather and analyze data and to prepare the forecast; and any prior experience with a technique.