1. Stats Tools for Analyzing Data
Chapter 18

2. Objectives Review of hypothesis Testing Overview of FMEA
Overview of Design of Experiment
Class Exercise

3. Hypothesis testing Definition
Procedure that summarizes data so you can detect differences among groups

4. Data Types
Discrete
Continuous

5. Hypothesis outcomes Truth Conclusion or Decision Groups Same
Groups Different
Accept Ho:
groups are same
No Error
Type II Error
Reject Ho:
groups are different
Type I Error

6. Procedure Null vs. Alternative Hypothesis
When comparing groups from different processes we assume:
Each process is stable
No time related changes are involved
Data is unbiased

7. Stat testing Data Type Test Purpose Continuous T – test
Compare Average
ANOVA
Compare 2 or more group averages
F- test
Compare 2 or more variances
Discrete
Chi-square
Compare 2 or more proportions

8. F test Is the ratio of 2 variances Is skewed with a tail to the right.
The lower bound is 0
The mode is almost 1
Depends on 2 separate d.f.
Assumes each group of data is a Normal distribution

9. FMEA (Failure Modes & Effects Analysis)
Purpose
A structured approach to identify, estimate, prioritize, and evaluate risk
Conducting FMEA
Brainstorm potential failure
Identify impact
Identify courses
Determine rate of ability to detect future failure
Calculate RPN
Focus on high RPN and reduce or eliminate those risks

10. Design of Experiment (DOE)
Identify “vital few”
Root cause analysis
DOE procedure
Class exercise

11. Any questions?