We have developed the design support system, "Design Support Navigator", for young mechanical engineers. Moreover, we have put this design tool into- Hitachi group's companies through a seminar for design of screw fastening with the use of one. However, in the traditional seminar, it was found that several students couldn't understand the lesson. There, the curriculum has been improved to move out a barrier to comprehension. Namely, main improvements were that exhaustive lesson of design procedure and review of exercise after the seminar. Additionally, operation screen of the design tool was improved for engineers to operate easily. It was shown by questionnaire after a seminar that the improved curriculum was very effective.