Analysis of double composite gear trains using the algebraic equations method involves a great deal of manual manipulations. Though the tedium of the process is reduced to some extent by the use of the General Theory, it will not lead to realization of computer algorithm generalized for all kinematic versions of a drive. The present algorithm based on the Unified Theory provides an efficient method to find values of the largest gear at a design optimization point Sop. The narrowing iterative step technique facilitates rapid convergence to the pivotal point. Six kinematic versions of open type having uniform group structure are analysed using the algorithm.