What are the four types of inspection stage

Four types of inspection stage:-
                                               1.Hold
                                               2.Witness
                                               3.Surveillance
                                               4.Review

1.Hold:- QA\QC organization shall be noticed of the timing of inspection or test in advance,inspection or test shall not carry out QA\QC organization representative in attendance.

2.Witness:- Copy above lining (Hold) inspection or test shall be performed as schedule.if the QA\QC organization representative is not present.

3.Surveillance:- QA\QC organization monitoring the work in process without notice from construction organization.

4.Review:- Review and approved all documents.