Cause and Effect Diagram aka Fishbone or ishikawa

1
Cause and Effect Diagram (aka Fishbone or
ishikawa
2
Why Fishbone?

• Helps insure a balanced list of ideas have been
  explored during brainstorming.
• Sort and relate the factors affecting a process
  when little quantifiable data is available
• Assists in determining root cause
• Helps overcome the theme effect

3
Fishbone How?

• Describe the problem of interest
• Decide the major causes typically the 6 Ms
  Manpower, Machines, Materials, Methods,
  Measurements, Mother Nature (Environment)
• Brainstorm more detailed causes Ask why 5 times
• Discuss causes and decide which are most
  important
• Drive those most important to root cause

4
Avoiding Group Think
5
Fishbone diagram example
Minitab
6
Use the 5 whys to determine root cause

• Ask Why 5 times
• The radio failed to transmit Why?
• The TCXO was off frequency Why?
• The crystal was not oscillating properly Why?
• There was a crack in the epoxy holding the
  crystal to the mount Why?
• The supplier was using an improper cure
  temperature for the epoxy. - Why?
• Suppliers cure oven is out of calibration.

7
Force Field Analysis

• Forces creative thinking on the issues of change
• Builds organizational consensus concerning the
  fuel for and the barriers to change
• Demonstrates to others that you have carefully
  considered your recommended course of action.

www.mindtools.com
8
Pareto Chart
9
Stakeholder Analysis
http//www.mindtools.com
10
Failure Modes, Effects, and Criticality Analysis
(FMECA)

• Locating the high-leverage opportunities
• Quantifying the potential risks

MIL-STD-1629
11
Learning Objectives

• Understand the use of the FMEA
• Learn the steps to develop the FMEA
• Summarize the different types of FMEA/FMECA
• Exercise to actually perform a FMEA

12
Aerospace FMECA Examples

• Satellite instrument redundancy analysis
• System level FMECA
• Functional circuit FMECA
• Piece part FMECA
• Military equipment fault detection and isolation
  analysis
• Process FMECA

13
What is a failure mode?

• The way in which something can fail

14
What is a FMEA/FMECA?
15
Why perform a FMECA?
16
The FMECA Process
17
The FMECA Form
18
The FMECA Procedure
19
The FMECA Procedure (Cont.)
20
(No Transcript)
21
Severity, Occurrence and Detection
22
Severity, Occurrence and Detection

• Severity
• 1 Not Severe 10 Very Severe
• Occurrence
• 1 Low Probability of occurrence 10 High Prob.
• Detection
• 1 Likely to detect 10 Not likely to detect

23
Risk Priority Calcuations
24
Excel Example
25
Homework 4 30 points

• Use the FMEA Homework 4 Excel spread sheet
• HWK 4 tab
• Complete cells B18-I25 inclusive
• Complete the rest of the row for the highest 2
  RPNs
• Notes Brainstorm 2 potential failure modes, each
  of which has two causes. Each cause has 2
  controls.
• May work with a partner
• Reading 20.11-20.18

Due January 31