Introduction to Time Series Forecasting

Slides:



Advertisements
Similar presentations
Decomposition Method.
Advertisements

ECON 251 Research Methods 11. Time Series Analysis and Forecasting.
1 1 Slide © 2011 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole.
Trends and Seasonality Using Multiple Regression with Time Series Data Many time series data have a common tendency of growing over time, and therefore.
Part II – TIME SERIES ANALYSIS C1 Introduction to TSA © Angel A. Juan & Carles Serrat - UPC 2007/2008 "If we could first know where we are, then whither.
Business Forecasting Chapter 10 The Box–Jenkins Method of Forecasting.
CHAPTER 5 TIME SERIES AND THEIR COMPONENTS (Page 165)
Ka-fu Wong © 2003 Chap Dr. Ka-fu Wong ECON1003 Analysis of Economic Data.
Modeling Cycles By ARMA
Chapter 5 Time Series Analysis
Data Sources The most sophisticated forecasting model will fail if it is applied to unreliable data Data should be reliable and accurate Data should be.
Modern methods The classical approach: MethodProsCons Time series regression Easy to implement Fairly easy to interpret Covariates may be added (normalization)
Part II – TIME SERIES ANALYSIS C2 Simple Time Series Methods & Moving Averages © Angel A. Juan & Carles Serrat - UPC 2007/2008.
Time Series Analysis and Index Numbers Introduction to Business Statistics, 5e Kvanli/Guynes/Pavur (c)2000 South-Western College Publishing.
Basic Business Statistics (9th Edition)
Time series analysis - lecture 1 Time series analysis Analysis of data for which the temporal order of the observations is important Two major objectives:
CHAPTER 18 Models for Time Series and Forecasting
© 2003 Prentice-Hall, Inc.Chap 12-1 Business Statistics: A First Course (3 rd Edition) Chapter 12 Time-Series Forecasting.
BOX JENKINS METHODOLOGY
Box Jenkins or Arima Forecasting. H:\My Documents\classes\eco346\Lectures\chap ter 7\Autoregressive Models.docH:\My Documents\classes\eco346\Lectures\chap.
© 2002 Prentice-Hall, Inc.Chap 13-1 Statistics for Managers using Microsoft Excel 3 rd Edition Chapter 13 Time Series Analysis.
1 1 Slide © 2011 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole.
Datta Meghe Institute of Management Studies Quantitative Techniques Unit No.:04 Unit Name: Time Series Analysis and Forecasting 1.
1 1 Slide © 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole.
TIME SERIES by H.V.S. DE SILVA DEPARTMENT OF MATHEMATICS
Examples of Forecasting Applications Service organizations (e.g. fast food restaurant) forecast customer demand to plan staffingService organizations (e.g.
Business Forecasting Used to try to predict the future Uses two main methods: Qualitative – seeking opinions on which to base decision making – Consumer.
Chapter 5 Demand Forecasting.
DSc 3120 Generalized Modeling Techniques with Applications Part II. Forecasting.
McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Time Series Forecasting Chapter 13.
Copyright © 2014, 2011 Pearson Education, Inc. 1 Chapter 27 Time Series.
Time Series Analysis and Forecasting
Lecture 7 Dr. Haider Shah.  Continue understanding the primary tools for forecasting  Understand time series analysis and when and how to apply it.
Week 11 Introduction A time series is an ordered sequence of observations. The ordering of the observations is usually through time, but may also be taken.
1 Forecasting Formulas Symbols n Total number of periods, or number of data points. A Actual demand for the period (  Y). F Forecast demand for the period.
© 1999 Prentice-Hall, Inc. Chap Chapter Topics Component Factors of the Time-Series Model Smoothing of Data Series  Moving Averages  Exponential.
1 Chapter 5 Demand Forecasting. 2 1.Importance of Forecasting  Helps planning for long-term growth  Helps in gauging the economic activity (auto sales,
Welcome to MM305 Unit 5 Seminar Prof Greg Forecasting.
Time Series Analysis and Forecasting. Introduction to Time Series Analysis A time-series is a set of observations on a quantitative variable collected.
COMPLETE BUSINESS STATISTICS
Economics 173 Business Statistics Lecture 25 © Fall 2001, Professor J. Petry
Time Series and Forecasting
Irwin/McGraw-Hill © Andrew F. Siegel, 1997 and l Chapter 14 l Time Series: Understanding Changes over Time.
Forecasting is the art and science of predicting future events.
Components of Time Series Su, Chapter 2, section II.
FORECASTIN G Qualitative Analysis ~ Quantitative Analysis.
1-1 Logistics Management LSM 730 Dr. Khurrum S. Mughal Lecture 22.
Chapter 20 Time Series Analysis and Forecasting. Introduction Any variable that is measured over time in sequential order is called a time series. We.
Managerial Decision Modeling 6 th edition Cliff T. Ragsdale.
Statistics for Business and Economics Module 2: Regression and time series analysis Spring 2010 Lecture 7: Time Series Analysis and Forecasting 1 Priyantha.
Chapter 15 Forecasting. Forecasting Methods n Forecasting methods can be classified as qualitative or quantitative. n Such methods are appropriate when.
Chapter 20 Time Series Analysis and Forecasting. Introduction Any variable that is measured over time in sequential order is called a time series. We.
Ian Newcombe CO 2 LEVEL RISE OVER 26 YEARS. DATASET Quarterly Mauna Loa, HI CO 2 Record Quarterly US gasoline sales Quarterly US car and light truck sales.
TIME SERIES MODELS. Definitions Forecast is a prediction of future events used for planning process. Time Series is the repeated observations of demand.
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.
Energy Consumption Forecast Using JMP® Pro 11 Time Series Analysis
Time Series And Business Forecasting
The role of hierarchical production planning in modern corporations (borrowed from Heizer and Render)
TIME SERIES ANALYSIS.
Chapter 6: Autoregressive Integrated Moving Average (ARIMA) Models
Statistics for Managers using Microsoft Excel 3rd Edition
Time Series and Their Components
Statistics and Modelling 3.8
Time Series and Forecasting
Forecasting Qualitative Analysis Quantitative Analysis.
Forecasting - Introduction
1 1 Slide © 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole.
Chap 1: Time Series Ani Shabri Department of Mathematical Sciences,
Forecasting Plays an important role in many industries
Presentation transcript:

Introduction to Time Series Forecasting Bernard Menezes with inputs from Kalam, Pankaj, Somsekhar, Timma

Time Series A sequence of observations of a quantifiable phenomenon recorded in increasing order of time

Time Series - Examples Stock price, Sensex Exchange rate, interest rate, inflation rate, national GDP Retail sales Electric power consumption Number of accident fatalities

Goals To UNDERSTAND the observed series To look into the future (by deducing from the observed patterns in the past)

Forecasting vs. Extrapolation

Error Measures RMSE MAE MAPE Max error

Patterns in the data Trend (linear, quadratic, S-shaped, etc.) Seasonality (by month or quarter of the year, day of the week or time of the day) Cyclicity (fashions come and go – notice the kinds of spectacle frames “fashionable” over the years)

Stationarity Should we care? Strict stationarity, covariance stationarity

Covariance, ACF, PACF What do these tell us?

Series Decomposition Many time series can be decomposed into following components Trend (T): Non-periodic component of time series Cyclical (C): Periodic component with period longer than seasonal period Seasonal (S): Recurring pattern (periodic component). Irregular (I): Residual after removing all three components above What’s the point?

Some Models for Decomposition Trend, seasonality and irregular component can combine in various ways such as Model 1: T * S * I Model 2: T * (S + I) Model 3: T + S + I The multiplicative model is more appropriate for demand sales

Cyclical Component? Generally trend and the cyclical component are analyzed/estimated together for ease of model construction

Experiment 1: MAPEs for different models

Experiment 2: Does Decomposition help? *indicates use of decomposition.

With and without Decomposition

With and without Decomposition (contd.)

Experiment 3: Which error measure do we use for the decomposed series?

Factoring expert advice How many experts do we select? Which of these is used for a particular point forecast? How do we weigh the advice of the experts? Do we dynamically change the above? How? Why?

AR1 0.5*X(t-1)+eps(t)

AR1 0.9*X(t-1)+eps(t)

AR1 0.2*X(t-1)+eps(t)

0.3*X(t-1)+0.5*X(t-2)+eps(t) AR2 0.3*X(t-1)+0.5*X(t-2)+eps(t)

MA1 0.8*eps(t-1)+eps(t)