Use a 4S to identify potential causes of a problem using the
following categories: Suppliers, Systems, Surroundings, and Skills.
Watch this video to learn more:
Answers the questions:
What are the potential causes
for a particular type of defect?
What are the process inputs
that contribute to variation in the process output?
When to Use
Purpose
Pre-project
Assist in project identification by linking potential causes to
defects.
Start of project
Assist in problem identification.
Mid-project
Identify potential process inputs to investigate in the project to
determine which inputs have a significant influence on the process
output.
Guidelines
Be sure to include project
stakeholders in the brainstorming sessions for building the fishbone diagram.
If the standard categories
of the causes are not appropriate for the problem, create new ones. Fishbone
diagrams can include any type of cause you want to investigate.
How-to
Gather the project team and
appropriate stakeholders for a brainstorming session.
For each category
(surroundings, suppliers, skills, and systems), list all possible causes or
process inputs. You may want to establish secondary categories for some or all
of the primary categories, then list the causes or process inputs under the
secondary categories.
Highlight causes (or inputs)
that are deemed to be the most important by the team.
Record the causes in a
fishbone diagram using the 4S template.