Fishbone Diagram Templates for Root Cause Analysis with Common Manufacturing Problems

Why start a root-cause analysis with a blank canvas? Are we better served starting with a blank canvas and an open mind, or do we put some common manufacturing problem areas in our template? Will the defaults in our template bias the discussion or make sure we always touch base on certain topics?

I was creating a template to facilitate meetings and ensure certain topics were always covered during a root-cause analysis. However, I found myself quickly filling up the paper.  I ended up switching to a tabloid page size, but I thought I should capture several iterations of the template to compare and decide which one would be more conducive to getting a good discussion started. 

Which one gets your brainstorming juices flowing? Which one will be more effective?

Do we start with a blank slate? 

Staring at a blank template or whiteboard can be intimidating at first. It is now up to the participants to come up with some ideas. However, strong personalities can lead the discussion in a single direction and we risk skipping some potential areas for causes. 

I personally like a little more guidance in a template. At least have some common headings for areas of discussion. This way we ensure that certain topics are discussed in every root-cause analysis. 

On the other hand, starting with a full fishbone diagram does not seem good either. Perhaps we start with the last one we used like the one above. The risk here is that we might get a feeling that we are done already. Looks finished to me. So perhaps we need a partial template like the one below. 

Maybe even this one is too full. But we might want to make sure certain common problems are always included in the discussion. 

Consider adding the following common sources of problems in manufacturing to your templates. 

1. Materials – Wrong, Deficient, Out of Spec – Is the material correct? Does it meet quality standards and specifications?

2. People – Skills and Certifications for Technicians and Inspectors - Are the employees performing the job qualified to do so? Is the training received sufficient?

3. Methods/Instructions – Incomplete, inaccurate or ambiguous – Are standardized work instructions provided? Are instructions illustrated? Are the work instructions missing a critical sentence or warning? 

4. Environment – Controlled, temperature, humidity, vibration, etc. – Is the assembly environment adequate to perform the work? Do the environment conditions need to be monitored for the particular process?

5. Machines/Equipment/Gages – Set up, maintenance, cycles – How do you know that a machine was properly configured to perform the work? When was the last machine maintenance?

6. Configuration – Wrong, obsolete, or changed configuration –  How do you know the correct configuration was selected when the assembly was worked?

7. Measuring/Test Equipment – Insufficient, inaccurate or incorrect measurements – How would you determine that the measuring/test equipment produced the desired result? When was the tool last calibration? 

8. Design – Rework, work-arounds, ECO/ECN – Was the problem or failure due to design? Due to building the wrong configuration?  Different revision levels? 

Which template do you prefer as a starting point? Empty or half full?

Comments

[Conrad]

Christopher wrote:

The idea that anybody could start with a blank slate is incorrect. Each person on the "brainstorming" team brings in access baggage" no matter what is written on the template.

... this is what it usually is
... I know what the fix should be
... boss will never change that so do not look at it
... why look at that, it has never happened before

Conrad wrote:

You reminded me of something I heard at a presentation. One company was using a software with a drop down list of "Causes" and found that the top Causes recorded were also the top Causes on the fixed drop down list. Were the users simply picking one of the top three or really going through the list of choices? Was the order of the list biasing the result? They went ahead and randomized the drop down list each time a user selected and guess what.... they results started to be more even spread : )
I guess it goes back to creating a culture where people see the value in the analysis.

Christopher wrote:

So true that based on confirmation and framing bias, you often get what you look for.
So the two sided coin problem:

Side 1: If I never new to look at that issue in the first place and human engineering is not an error I am familiar with, the human engineering issue will never show in my analysis.

Side 2: If it is in my things to look for it will always show up.. right? Depends: I have 12 inches on my ruler but that is not what I mark every time... it depends on what I need and what the facts are.

[Snehan]

The Beauty of the fishbone diagram is that it can be used for any organization irrespective of their size.

[David Mitchell]

I think I could write a list of generic impacts for most organisations across a range of industries but that doesn't mean that they are the main X's and Y's for your organisation.

While I agree that everyone brings their own bias into a workshop, I think that by pre-filling the template that you risk putting ideas in participants minds rather than allowing them to identify the top issues for your actual operation.

By all means have your list available and have a sense of what the biggest impacts are, and if they don't come out then prompt the participants but don't start there.

Using a SIPOC in the define phase followed by an AS IS process map in measure will allow you to start to identify the Y's and X's but ultimately it will be the people who do the tasks as part of the C&E workshop that will let you know what's really happening so I'd give them the chance to fill the board before you do.

Regards, David