Forecasting IME 451, Lecture 2. Laws of Forecasting 1.Forecasts are always wrong! 2.Detailed forecasts are worse than aggregate forecasts! Dell forecasts.

Slides:



Advertisements
Similar presentations
Forecasting OPS 370.
Advertisements

Operations Management Forecasting Chapter 4
Forecasting 5 June Introduction What: Forecasting Techniques Where: Determine Trends Why: Make better decisions.
Forecasting Ross L. Fink.
Chapter 12 - Forecasting Forecasting is important in the business decision-making process in which a current choice or decision has future implications:
Forecasting 1 Linkages How much we are going to sell is obviously important to marketing Forecasts help us to plan investments - or to determine if an.
Forecasting.
CHAPTER 3 Forecasting.
Chapter 3 Forecasting McGraw-Hill/Irwin
Chapter 13 Forecasting.
FORECASTING. Types of Forecasts Qualitative Time Series Causal Relationships Simulation.
Forecasting & Time Series Minggu 6. Learning Objectives Understand the three categories of forecasting techniques available. Become aware of the four.
Demand Management and Forecasting. Types of Forecasts Qualitative Time Series Causal Relationships Simulation.
Operations Management R. Dan Reid & Nada R. Sanders
Operations Management Forecasting Chapter 4
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J Operations Management Forecasting Chapter 4.
Forecasting McGraw-Hill/Irwin Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved.
FORECASTING Operations Management Dr. Ron Lembke.
McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. 3 Forecasting.
Mr. David P. Blain. C.Q.E. Management Department UNLV
Demand Forecasts The three principles of all forecasting techniques: –Forecasting is always wrong –Every forecast should include an estimate of error –The.
Slides 13b: Time-Series Models; Measuring Forecast Error
Fall, 2012 EMBA 512 Demand Forecasting Boise State University 1 Demand Forecasting.
BIS Application Chapter two
LSS Black Belt Training Forecasting. Forecasting Models Forecasting Techniques Qualitative Models Delphi Method Jury of Executive Opinion Sales Force.
Samuel H. Huang, Winter 2012 Basic Concepts and Constant Process Overview of demand forecasting Constant process –Average and moving average method –Exponential.
Group No :- 9 Chapter 7 :- Demand forecasting in a supply chain. Members : Roll No Name 1118 Lema Juliet D 1136 Mwakatundu T 1140 Peter Naomi D 1143 Rwelamila.
Introduction to Forecasting COB 291 Spring Forecasting 4 A forecast is an estimate of future demand 4 Forecasts contain error 4 Forecasts can be.
The Importance of Forecasting in POM
Demand Management and Forecasting
Forecasting Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill.
Operations Management
3-1Forecasting William J. Stevenson Operations Management 8 th edition.
Forecasting Professor Ahmadi.
DSc 3120 Generalized Modeling Techniques with Applications Part II. Forecasting.
1 DSCI 3023 Forecasting Plays an important role in many industries –marketing –financial planning –production control Forecasts are not to be thought of.
DAVIS AQUILANO CHASE PowerPoint Presentation by Charlie Cook F O U R T H E D I T I O N Forecasting © The McGraw-Hill Companies, Inc., 2003 chapter 9.
MBA.782.ForecastingCAJ Demand Management Qualitative Methods of Forecasting Quantitative Methods of Forecasting Causal Relationship Forecasting Focus.
Operations Research II Course,, September Part 6: Forecasting Operations Research II Dr. Aref Rashad.
Forecasting February 26, Laws of Forecasting Three Laws of Forecasting –Forecasts are always wrong! –Detailed forecasts are worse than aggregate.
Demand Management and Forecasting Module IV. Two Approaches in Demand Management Active approach to influence demand Passive approach to respond to changing.
McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. 3 Forecasting.
1 1 Slide Forecasting Professor Ahmadi. 2 2 Slide Learning Objectives n Understand when to use various types of forecasting models and the time horizon.
Forecasting. 預測 (Forecasting) A Basis of Forecasting In business, forecasts are the basis for budgeting and planning for capacity, sales, production and.
Forecasting Chapter 9. Copyright © 2013 Pearson Education, Inc. publishing as Prentice Hall Define Forecast.
Reid & Sanders, Operations Management © Wiley 2002 Forecasting 8 C H A P T E R.
15-1 Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall Forecasting Chapter 15.
McGraw-Hill/Irwin Copyright © 2010 by The McGraw-Hill Companies, Inc. All rights reserved. 3 Forecasting.
Business Processes Sales Order Management Aggregate Planning Master Scheduling Production Activity Control Quality Control Distribution Mngt. © 2001 Victor.
Welcome to MM305 Unit 5 Seminar Prof Greg Forecasting.
15-1 Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall Forecasting Chapter 15.
© Wallace J. Hopp, Mark L. Spearman, 1996, Forecasting The future is made of the same stuff as the present. – Simone.
Forecasting Demand. Forecasting Methods Qualitative – Judgmental, Executive Opinion - Internal Opinions - Delphi Method - Surveys Quantitative - Causal,
MGS3100_03.ppt/Feb 11, 2016/Page 1 Georgia State University - Confidential MGS 3100 Business Analysis Time Series Forecasting Feb 11, 2016.
1 1 Chapter 6 Forecasting n Quantitative Approaches to Forecasting n The Components of a Time Series n Measures of Forecast Accuracy n Using Smoothing.
Forecasting is the art and science of predicting future events.
CHAPTER 12 FORECASTING. THE CONCEPTS A prediction of future events used for planning purpose Supply chain success, resources planning, scheduling, capacity.
Forecasting Demand. Problems with Forecasts Forecasts are Usually Wrong. Every Forecast Should Include an Estimate of Error. Forecasts are More Accurate.
Forecasting Production and Operations Management 3-1.
McGraw-Hill/Irwin Copyright © 2009 by The McGraw-Hill Companies, Inc. All Rights Reserved. Chapter 3 Forecasting.
Demand Management and Forecasting Chapter 11 Portions Copyright © 2010 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill/Irwin.
Forecas ting Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill.
Forecast 2 Linear trend Forecast error Seasonal demand.
Demand Forecasting Production and Operations Management Judit Uzonyi-Kecskés Ph.D. Student Department of Management and Corporate Economics Budapest University.
Chapter 11 – With Woodruff Modications Demand Management and Forecasting Copyright © 2010 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill/Irwin.
3-1Forecasting Weighted Moving Average Formula w t = weight given to time period “t” occurrence (weights must add to one) The formula for the moving average.
Demand Forecasting Production and Operations Management Judit Uzonyi-Kecskés Ph.D. Student Department of Management and Corporate Economics Budapest University.
Welcome to MM305 Unit 5 Seminar Dr. Bob Forecasting.
Welcome to MM305 Unit 5 Seminar Forecasting. What is forecasting? An attempt to predict the future using data. Generally an 8-step process 1.Why are you.
Demand Management and Forecasting
Presentation transcript:

Forecasting IME 451, Lecture 2

Laws of Forecasting 1.Forecasts are always wrong! 2.Detailed forecasts are worse than aggregate forecasts! Dell forecasts 410,000 orders for new computer systems in 2004 and 465,000 in 2005 Forecasts for the percentage of laptops vs. desktops are less reliable, as are configurations of processor speed, monitor style, hard drive size 3.The further into the future, the less reliable the forecast will be! In 2015 will 750,000 computer orders be filled, or 890,000?

Importance of Forecasting Forecasts provide the only sensible way to plan for future production and inventory Strive for robust forecasting decisions e.g., with agile manufacturing, plants can better respond to changes in product types and volumes, despite forecasting errors Cross-train workforce Shorten manufacturing cycle times to reduce dependence on forecasts

Forecasting Methods Qualitative – attempts to develop likely future scenarios using human expertise Delphi method – survey experts about likelihood of future events (technology introduction, industry trend) until consensus or stability is attained Quantitative – attempts to predict future based on a mathematical model Causal – predict a parameter as a function of other parameters (e.g., interest rates, GNP growth, etc) Time Series Models – predict a parameter as a function of its past values (e.g., historical demand)

Causal – Simple Linear Model Y – parameter to be predicted X i – predictive parameters b i – constants that are statistically determined from data (and b 0 is the Y-intercept of the straight line that best fits the data) Regression analysis is used to fit a function to the data

Time Series – Moving Average Simple average method Assumes no trend Moving average eliminates older data and considers only the last m time periods Higher values of m make model more stable, but less responsive to actual process changes Underestimates increasing trends; Overestimates decreasing trends

Exponential Smoothing Alpha is chosen by the user, 0 <  < 1 Lower values of  make model more stable, but less responsive to actual process changes Underestimates increasing trends; Overestimates decreasing trends Try different values for  and see which one generates a curve that follows historical data

Exponential Smoothing with a Linear Trend Tracks data with upward or downward trends  and  are smoothing constants between 0 and 1

Winters Method for Seasonality Tracks data with seasonal trends – ice cream, snow shovels, air conditioners, etc.   and  are smoothing constants between 0 and 1 c(t) is ratio of demand during period t to average demand during the season (the sum of c(t) factors = N if there are N periods in the season)

Evaluating Forecasting Models Mean absolute deviation, mean square deviation, or bias are used to evaluate models Minimize MAD and MSD, which are always positive BIAS should be as close to 0 as possible. But, this only indicates that errors are balanced +/-, not accurate

Final Note: Forecasting is an art…