Non-destructive testing can be arranged at different stages of the manufacturing process. Inspection timing should be determined based on defect risk, surface condition and accessibility of subsequent processes.

The timing of inspections determines their value

The inspection conditions may vary before and after processing, before and after assembly, or before and after surface treatment. When planning the process, it is important to choose the appropriate timing based on the issues that need to be identified. Inspections should not be limited to the final stage of production; they should be aligned with the actual manufacturing status of the parts.

Incorporating inspection into the transfer process

Transfer documents should specify the items to be inspected, the methods to be used, and the conditions for approval. Manufacturers should prepare the parts according to these specifications, while inspectors should confirm the acceptance criteria. When both parties have the same understanding of the status of the parts, it helps to reduce the number of parts being returned for re-inspection or requiring repeated preparation.

When planning, it is important to clarify the objects of inspection and the criteria for acceptance. Inspection reports should indicate the actual coverage area, so that manufacturers and quality personnel can understand the results correctly.

How results are returned to the production site

The locations of any abnormalities reported in the reports should be clearly identifiable on-site. Schedules, characteristic codes, and clear scope descriptions can facilitate further review and action. A general conclusion should not be directly translated into corrective actions without confirmation of the specific areas involved.

Continuing retest records

After the issue has been addressed, a retest should be conducted as required, ensuring that the original findings, actual actions taken, and retest results are consistent. This not only confirms the current state of the parts but also provides valuable data for future process improvements.

Process example: Inconsistent inspection conditions and requirements

It is assumed that the parts are sent for inspection as planned. However, if their surface condition or assembly state does not meet the requirements of the planned method, the inspection process may not be able to proceed as intended. Manufacturing and inspection should clearly define the acceptance criteria during the planning phase, and any necessary checks should be performed before the parts are transferred to the next stage of production. This helps to avoid wasting inspection resources on redundant preparations, and also reduces confusion caused by sudden changes in the inspection plan.

Common problems: What to do if missed inspections are discovered after manufacturing is completed?

It is necessary to assess whether the current state allows for obtaining the desired information and to determine additional measures according to the appropriate procedures. Simply signing off on records or using inspections with a different scope should not be done without proper justification.

Key points for verification during implementation

• Timings are appropriate
• Clear status for inspection
• Results are traceable
• Continuous retest chain

After an abnormality is detected, it should be handled according to the review process, and records of subsequent actions and retests should be kept.