Page 23 - Injection Molding Advanced Troubleshooting Guide

4 1 Troubleshooting Methodology

Systematically
Think
Observe
Proceed

This STOP methodology of troubleshooting is meant to do exactly what it says and
stop before jumping to conclusions.

Development of STOP
This thought process came years ago while interviewing process engineers
and technicians. I would always try to gauge their knowledge by asking
questions about how they would handle a problem such as a short shot. The
answers I received were usually correct to a point but obviously quite
diverse. Often times the answers provided could be the right ones, but,
without knowing what was happening, could also lead to disaster. When I
reviewed my own mentality, I came to understand that the first thing I would
do when troubleshooting was to stop and really examine what was happen-
ing. The concept of STOP troubleshooting came about as an easy way to
train people in the methodology of troubleshooting.
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1.4.1„ STOP: Systematically

In the STOP methodology, the S stands for systematically. All troubleshooting
should be conducted in an organized and systematic approach. Having a system-
atic approach will help ensure the root cause of the problem is truly resolved. As a
problem is addressed a systematic approach will make it easier to avoid missing a
potential cause.
Part of the systematic approach to troubleshooting breaks the problem into four
key categories. Many people are familiar with the 5M’s often used for fishbone
diagrams which are man, method, machine, measurement, and material. For sys-
tematic injection molding troubleshooting the 4M’s we focus on are:
1. Molding process
2. Mold
3. Machine
4. Material
These 4M’s are the key items that a troubleshooter can impact. The “man” is not
included because a person can impact any of the 4M’s. Each of the 4M’s must be
considered for potential root causes when troubleshooting. By reviewing the 4M’s