We have investigated a methodology to develop carbon fiber reinforced plastic (CFRP) components based on strength and design simulations in the framework of high-performance K computers. Mesoscale simulations to distinguish between carbon fibers and resins seem promising for overcoming the conventional trial-and-error design method. This methodology is currently applied to the design of CFRP hydrogen tanks in terms of mesoscale parameters such as winding path, resin strength, and manufacturing error. In addition, from the viewpoint of moldability, carbon fiber reinforced thermalplastic composites are promising. We have been developing a simulation system to predict the mesoscale structure of carbon fibers after molding.