Modified variational iteration method for solving a neutral functional-differential equation with proportional delays

Purpose - The purpose of this paper is to introduce an auxiliary parameter into the well-known variational iteration algorithm which proves very effective to control the convergence region of approximate solution.Design methodology approach - In this paper, an auxiliary parameter is introduced into the well-known variational iteration algorithm which proves very effective to control the convergence region of approximate solution.Findings - The present technology provides a simple way to adjust and control the convergence region of approximate solution for any values. An optimal auxiliary parameter can be obtained by the error of norm two of the residual function.Originality value - It is confirmed that submitted manuscript is original and is not being considered in any other journal.