This work has been funded under the AFOSR Grant # F49620-03-1-0011 and Army Research Lab Contract # DAAD17-02-P-0398 and DAAD 19-01-1-0742. B.L. Adams acknowledges support of Army Research Office, Proposal No. 42566-MS. The authors express their sincere gratitude to Professor Surya Kalidindi, for helpful suggestions and correspondence for the derivation of the processing path functions. A new methodology based on a conservation principle in the orientation space is developed to simulate the texture evolution in a cubic-orthotropic polycrystalline system. A least squares error method was used to improve the accuracy of the simulation results obtained from the texture evolution function. The model is applied to uniaxial tension, compression and rolling for a large deformation of more than 50% using a single evolution parameter. The validity and application range of this new model are discussed by simulating and predicting texture evolution during different loading conditions. The new methodology provides a family of texture evolution paths and streamlines which empowers the materials designer to optimize the desired microstructure.