Picard, Lawrence G., Sr. (1992, ASQC) Charleston Naval Shipyard, Charleston, SC 29408-6100
An independent inspection required on in-process or completed work is, in fact, a request for two inspections: one by the worker and a second by the inspector who verifies that the work conforms with the plan and specifications.
One method used to ensure that the employee performs an inspection of completed work is the dual-signature system of verification. This system requires that the employee sign that his or her work meets the requirements of the plan and specification before the independent inspection takes place.
When the work is not within tolerance, the verification block remains unsigned, and a deficiency log is attached to the work procedure. The Charleston Naval Shipyard realized the following benefits as a result of the dual signature process: (1) improved product quality, (2) reduced rework, (3) emphasis on worker responsibility for the final quality of work, and (4) minimized possibility of inspection error.
Inspection organizations can not replace the inspections performed by employees who perform the work; the dual signature system helps ensure that employees inspect their completed work and verify that it meets the plan and specifications before an independent inspection occurs.