The findings were summarized as follows. The safety check by manufacturer showed that 6 of 13 companies are over the average occurrence of defects. It was expected that there would be a difference between manufacturing technology capability and production system of each manufacturer. Consequently, manufacturers should institutionally improve and strengthen certification items for the upward standardization of safety certification before factory. Second, the safety check by year showed that the results of this study accord with those of previous studies on defect time. Consequently, manufacturers should classify the 3-year-old equipment for vehicle-mounted MEWP into a special check subject to do a nondestructive test according to proven results, and also reflect the test in a safety test system to do regular preventive activities of equipment defects. Third, the safety check by part showed that the boom and outrigger parts of vehicle-mounted MEWP have the most defects. Stress concentration resulted in defects as the boom part was most frequently operated in the structural parts for a real work. To prevent this, it is suitable to improve the hardness of boom materials. The outrigger part needs improvement in safety devices with materials. As an outrigger supports the overturning moment of equipment, it is most affected by its load based on the operating radius, resulting in fatigue crack.

Though most businessmen have recognized the necessity of special purpose vehicles, they have a great difficulty in purchasing them for small scaled work condition especially. In other words, because of special purpose vehicles high cost, maybe they will hesitate to buy them for only one purpose. For this reason, there is a great need to develop special purpose vehicles which can be used for various purposes and low cost. In this study, using the design program like CATIA/IDEAS, we have developed lift system on the new concept by applying a portion of loading case spaces practically equipped for 1 ton truck.