1. IENG 423 Design of Decision Support Systems Modeling with Excel Excel Basics Data Analysis

2. Dealing with Data So, what does this tell you? Can you answer the question – which supplier is supplying us with better quality parts?

3. Dealing with Data What if I told you that the Mean time to failure for parts from Supplier A is 187.27, and Supplier B is 176.07 Now, can you answer the question?

4. Dealing with Data..but are there any limits to your conclusion? … this may say something about last week’s parts shipments,…

5. Dealing with Data..but what about next week’s or the rest of the year

6. Dealing with Data Having the data may not be enough Too much data Complex data No obvious answer Subtle differences or relationships We need to tools to boil down the data to something meaningful

7. Dealing with Data Data Analysis (or Statistical Analysis) Two major types Descriptive Statistics – describes a set of data Inferential Statistics – allows you to draw inferences, make conclusions about data

8. Dealing with Data Descriptive Statistics – describes a set of data A value that “best” represents character of a set of data For example, the arithmetic mean is the most representative value of a set of data What does that means? Is it always the best?

9. Dealing with Data Inferential Statistics Analytic technology to help you make inferences, draw conclusions.. …what are you making inferences about?

10. Data Analysis Excel has a wide variety of statistical functions in its function library Also, Excel has a substantial collection of Data Analysis Program available as an optional Add-in

11. Data Analysis Add-in Programs in Excel Anova – Single Factor Anova – Two Factor without replication Anova – Two Factor with replication Correlation Covariance Descriptive Statistics Exponential Smoothing …

12. Data Analysis Add-in Programs in Excel F-Test – Two sample for variances Fourier Analysis Histogram Moving Average Random Number Generator Rank & Percentiles Regression …

13. Data Analysis Add-in Programs in Excel Sampling t-test: Paired two sample for means t-test: two sample assuming equal variances t-test: two sample assuming unequal variances z-test: two sample for means …

14. Dealing with Data Some widely used statistical/data analysis packages SAS  http://www.sas.com/ SPSS  http://www.spss.com/ S-Plus  http://www.insightful.com/products/splus/default.asp R  http://www.r-project.org/ http://www.r-project.org/ STATISTICA  http://www.statsoft.com/index.htm http://www.statsoft.com/index.htm

15. Dealing with Data An a ton of others See http://en.wikipedia.org/wiki/List_of_statisti cal_packages http://en.wikipedia.org/wiki/List_of_statisti cal_packages

16. Dealing with Data …a little rusty with statistics? You might want to check out.. http://www.statsoft.com/textbook/stathome.html An $80 book, online for free