This study aims to provide an algorithmic solution to create convertible products, which is then used to fabricate composite components. The shortest optimization path is adapted to this specific conversion problem. The first task was consecutive subcritical water processing and enzymatic hydrolysis optimized by response surface methodology, whereas the second task focused on lignin added composite material to fabricate reinforcement composite and reduce resin rate. The maximum fermentable sugar amount was obtained as 310.9 g/kg under the optimized conditions of 150 bar, 150.9 °C at a flow rate of 8 ml/min for 45 min. Subsequent to subcritical water extraction, remaining solids were processed with enzymes to breakdown cellulose for conversion into simple sugars that can be fermented into biofuels and chemicals, where the highest sugar concentration of 429.45 g/L was reached. Finally, lignin was mixed with epoxy resin at 3 different ratios to fabricate lignin-based glass fiber reinforced composite material.