Original Date: 10/20/1997
Revision Date: 01/18/2007
Information : Self-Inspection System
Instead of traditional inspection methods, Northrop Grumman uses a Self-Inspection System (SIS) for quality checks. Based on a six-step process, mechanics perform their own operational inspections with appropriate monitoring to ensure high quality workmanship of the product. The six steps are: (1) set criteria, (2) identify process candidates, (3) training, (4) observation, (5) recognition, and (6) monitor.
The six-step systematic process (Figure 2-12) provides consistent application of the SIS methodology in the workplace. In Step 1, engineering, quality assurance, and mechanical expertise are combined to define what needs to be done, how to accomplish it, and how to measure it. By setting the criteria, the process fully defines the SIS methodology for the mechanics and sets the stage for monitoring the performance. Step 2 uses a selection method (Figure 2-13) to identify the key processes and ensure that the SIS methodology is applied to the processes of most importance. This selection method promotes objective determination of the most important processes for SIS applications. During Step 3, mechanics receive extensive training on applying the SIS methodology. The abstract on New Directions Training Program provides additional details on this procedure.
After formal training, the mechanics return to the factory floor and undergo an additional ten-week, on-the-job training period. At this stage (Step 4), observed applications are done, and recognition (Step 5) will follow if the mechanic’s performance fulfills the required standards. Upon meeting the standards, mechanics receive the quality, self-inspection stamp authorization as well as an increase in pay. Step 6, an ongoing monitoring stage, consists of two factors: tracked escapes and process audits. Tracked escapes are defects that are detected downstream from the mechanic’s operations. Based on these defects, root cause analyses are done to determine the causal factors for the escapes and the corrective actions implemented. Process audits are conducted to examine all facets of the operations being performed and to detect weaknesses or areas for improvement. Findings are then tracked to closure with follow-up process audits being done to verify the corrective action. These monitoring methods, which are included in the work instructions, are key aspects for customer acceptance of the SIS methodology.
Northrop Grumman first initiated the SIS methodology in the B-2 Bomber Production Facility. In a little more than two years, the facility reduced its nonconformance costs from 15% to 6%, and the results at El Segundo are similar. A slight decrease in cycle time was achieved by eliminating a separate inspection step in the production process. In addition, no increase in touch labor costs occurred. For every ten inspectors used in the original system, the company only needs one or two process auditors in the new system.
Figure 2-12. Self-Inspection Process Steps
Figure 2-13. Selection of a Key Process
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