8D (Eight Disciplines) is a team-based problem-solving methodology that walks a quality issue through eight disciplines: form a team, describe the problem, implement interim containment, identify the root cause, choose and verify permanent corrective actions, implement them, prevent recurrence, and recognize the team.
It originated at Ford and is the de-facto standard format for supplier corrective-action requests in automotive and aerospace. It combines containment (protect the customer now) with rigorous root cause corrective action (fix it forever).