My cousin's parents applied and were rejected the first time. Second time they went showing bigger bank balance. That helped and they got the visa. The biggest thing they look for is your parents tie to Nepal, money helps but if you have other reasons like other young siblings, good job that helps. Factory work should have helped, maybe he might want to get some high profile recommendations from factory on how important his position is to the factory etc etc.

All I have to say is follow above advice and try again.