Problem Solving

Tools for solving problems

                       

Overview

• Tools
  • Root Cause (Fishbone) Diagram
  • Reverse Fishbone Diagram

NOTE: Content here are my personal opinions, and not intended to represent any employer (past or present). “PROTIP:” here highlight information I haven’t seen elsewhere on the internet because it is hard-won, little-know but significant facts based on my personal research and experience.

Tools

There are several conceptual and practical tools:

7 QC Tools used in Six Sigma:

1. Flowchart
2. Check Sheets
3. Pareto Charts with a cumultive line (to separate the vital few from the trivial many)
4. Fishbone Diagram (5 Whys)
5. Histogram
6. Scatter Diagrams (XY Scatter Chart) and Correlation
7. Control Charts

Root Cause (Fishbone) Diagram

The fishbone diagram visually presents the results of brainstorming exercise aimed at identifying root causes of a problem.

VIDEO: Deming describes use of what he calls the (Kaouru) Ishikawa diagram, which others call a fishbone (or herringbone) diagram.

1. The starting point is a short description of a single problem, in a box at the right side of the page.

   State as a question, such as “why did the website crash”?

   Alternately, the problem can be associated with a KPI (Key Performance Indicator), such as:

   • Cycle Time too slow
   • Time to Retore too high
   • Changes take too much time
   • People are waiting for others too often

   • Too many work items “dropped through the cracks” - no accountability (no aging reports for management)

   • Too many work items for the number of resources assigned
   • Changes take too much effort

   • Costs too high

   • Quality (Availability) too low - not meeting SLAs/SLOs
   • Too many errors
     
     

   The problem can be the biggest bar (the largest contribution) to causes of problems in a Pareto chart.

2. Draw a horizontal line and “ribs” to each category. When working on-site, this can be on a large white-board where participants paste sticky notes.

   A “fishbone” provides a visual approach to organize ideas into categories.

3. Define categories (buckets) to prompt brainstorming of causes:

   My six-category example: Surroundings/Environment, People/Skill, Measurement/Information, Method/Process, Machine/System/Equipment (Physical causes), Material/Supplier

   Common categories: People, Information, System, Process (PIPS)

   Common categores in services: Surroundings, Suppliers, Systems, Skill

   Common categories in manufacturing 8M’s: Manpower, Money, Machine/Materials, Methods, Maintenance, Metrics, Mother Nature (culture), Management

   https://www.youtube.com/watch?v=XinW5dwuKsI

4. Brainstorm causes under each category.

   During this step, don’t throw out suggestions that may have little impact on the problem.

   Remember this is partly a team-building exercise, where you’re building fun memories.

   Jay calls diagrams that are too big “whalebone” diagrams.

5. Branch out each cause by adding a leaf after asking Why (5 times).

6. Review categories to Analyze results.

   Have each team member silently assign a priority to each cause.

7. Create an Action Register to track follow-up on ideas.

   A common action is to collect more

8. Prioritize actions

9. Define countermeasures (Step 5 of A3)

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Reverse Fishbone Diagram

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