Once a Controlled Shipping (CS1/CS2) or GP-12 mandate is in place, the immediate crisis is averted. But the true work—finding and eliminating the core problem—begins. Here are the five essential Root Cause Analysis (RCA) tools every automotive supplier must master.
The goal of quality containment is to stop the defect flow and protect the customer. The goal of Root Cause Analysis is to ensure the defect never happens again. Moving from a temporary fix to a Permanent Corrective Action (PCA) requires structured, data-driven investigation. Without a formal RCA process, you risk falling back into the same quality escape pattern.
While your third-party inspection partner provides the necessary data and insulation, your internal team must use that data to drive change. Here are five of the most powerful and common RCA tools used in the automotive industry.
5 Essential Root Cause Analysis Tools
1. The 5 Whys
This is the simplest tool, perfect for quickly identifying the chain of causation. Starting with the observed failure (e.g., “The part was rejected”), you ask “Why?” repeatedly until you reach a process or system failure that can be addressed. It’s most effective when combined with data collected during sorting and rework activities, which provides the initial failure point.
2. Fishbone Diagram (Ishikawa or Cause-and-Effect)
This visual tool categorizes potential causes into major groups—often the 6 Ms: Manpower, Machine, Method, Material, Measurement, and Mother Nature (Environment). It helps teams brainstorm comprehensively, ensuring no potential factor related to the defect containment effort is overlooked. It’s an ideal tool for facilitating team discussions after a major quality failure.
3. Is/Is Not Analysis
Used to precisely define the scope of the problem. You document what the problem IS (where, when, what, extent) and, critically, what it IS NOT. For example, the defect IS on the morning shift, but IS NOT on the afternoon shift. This isolation of the problem boundary immediately narrows the focus of the investigation and is crucial for escaping the CS1/CS2 stage.
4. Pareto Chart (80/20 Rule)
A visual tool that organizes defect data (provided by your third-party quality inspection report) by frequency. By charting the number of occurrences of each defect type, you quickly identify the “vital few” problems that account for most of the failures. This tool ensures your team prioritizes corrective actions on the sources that will yield the largest quality improvement.
5. Scatter Diagram
Used to test theories about potential relationships between two variables. For instance, is the part dimension defect related to the temperature of the machine, or the humidity in the facility? If a theory about a variable (e.g., machine speed) is a potential root cause, the scatter diagram provides a visual representation to confirm or deny the correlation, leading to a truly effective Permanent Corrective Action.
The Next Step: From Data to Permanent Action
Successful quality containment gives your team the breathing room needed to perform these analyses. The data gathered during GP-12 or Controlled Shipping is the evidence you need. By systematically applying these RCA tools, you move beyond the crisis and achieve the sustained quality demanded by the automotive sector, ultimately leading to the successful exit from containment mandates.
Get the Data You Need for Effective RCA
Our third-party inspection reports provide granular, real-time defect data—the essential ingredient for accurate Root Cause Analysis. Partner with us to solve the problem permanently.