The paper presents a feature based upper-bound model to analyze three dimensional complex geometry tube extrusion process having generalized die and mandrel profiles. The analysis is based on kinematically admissible velocity field to obtain the optimal extrusion pressure by optimizing the die length using Variable Interval Golden Section Method. Various parameters such as product profile, shape complexity factor, die and mandrel profiles, reduction, friction, ram velocity and die length, etc., have been chosen for the process and parametric study on extrusion. The experimental and the proposed analytical results have been compared with experimental work by authors and analytical works of other researchers to validate the model that shows good agreement.