Terrestrial neutron is being recognized as a major source of single event effects (SEEs) including soft-error of semi-conductor devices at the ground level. As semiconductor device scaling nose-dives into sub 100nm, the possible threat from single event effects is apparently growing onto IT systems that require a great number of electron devices. The modes of SEEs, however, are reportedly diverging on annual base and thus methods to quantify such effects are getting more and more complicated even for device level. In the present paper, current situation on neutron-induced SEEs are reviewed and benchmark studies are proposed to make the effects of SEEs on the reliability of IT infrastructure clear.