*3.3. Develop an Interim Containment Action (D3)*

Since 8Ds teamwork members have enough knowledge on the product/process, possible corrective actions must be undertaken in order to control the problem and avoid its expansion. Teamwork members should define and implement those intermediate actions that will protect the customer from the problem until permanent corrective actions are implemented. Additionally, interim containment actions should follow the ISO/TS 16949:2009 quality system and rely on the current approach to appropriately determine and verify the effectiveness of these actions. (ISO/TS 16949:2009 is a technical specification which defines the quality management system requirements for the design, development, production, relevant installation, and service of automotive-related products [23]). In addition, this step is aimed to preserve evidence and stop the outcome from being irremediably enlarged before the problem can be solved and the goal achieved. Some tasks must be monitored to ensure compliance with the requirements, such as documenting, control planning, scheduling, and assigning the specific needs according to the problem that is being solved [23].

#### *3.4. Define and Verify Root Causes (D4)*

This step refers to identification of all the applicable causes that could explain why the problem occurred, as well as the reasons why the problem was not perceived the first time it occurred. All causes shall be verified or proved, and not determined by assumptions. Experts recommend using the Ishikawa's five-whys diagrams to map causes against the identified effect [35]. The 5W2H method is used to make diagrams about customer requirements, review the problem-solving process, and analyze the problem [23].

#### *3.5. Develop Permanent Corrective Actions (D5)*

Depending on the different causes of the problem, several suitable strategies ought to be proposed. Therefore, either results must be reviewed and the required adjustments have to be made, or some

permanent corrective actions must be taken [23]. Finally, a quantitative method ought to be performed through pre-production programs to confirm that the selected corrections will solve the problem [35].
