This paper addresses the challenge of solution verification and accuracy assessment for computing complex Partial Differential Equation (PDE) model. Our main target applications are bio-heat transfer and blood flow simulation problems. However our long term goal is to provide a postprocessing package that can be attached to any existing numerical simulation package, for example widely used commercial codes such as ADINA, Ansys, Fluent, Star-CD etc., and provide an a posteriori error estimate to their simulation.