Actually, this tool is not only for GM. In the presentation, we were Tier 1 suppliers and they were talking about spreading it along the supply chain. (Perharps only to Tier 2 level)
The aim is to avoid recurrence in incidents that could cause a line stoppage because of quality reasons.
Through 5 Why analysis, systemic root causes should be detected in all 3P whenever an incident happens. Finally, a pareto chart should be built to focus only on main systemic issues.
If any of you are interested in having further information on this tool I have some material available.