Abiodun Opanuga, Jimevwo Godwin Oghonyon, Oluwole Odetunmibi, Designing a Variable Step Size For the Successful Implementation of P(EC)m and P(EC)mE Mode, Research Journal of Applied Sciences, Volume 12,Issue 1, 2017, Pages 7-13, ISSN 1815-932x, rjasci.2017.7.13, (https://makhillpublications.co/view-article.php?doi=rjasci.2017.7.13) Abstract: The successful implementation of P(EC)m and P(EC)mE mode otherwise known as block predictor-corrector methodsis solely dependent on the principal local truncation error of both predictor and corrector methods of the same order. The development of this platform is built on formulating a class of P(EC)m and P(EC)mE mode that possesses the same order but different k-step. Nevertheless, designing of a variable step size on P(EC)m and P(EC)mE mode attracts a lot of computational benefits which guarantees convergence, step size control, tolerance level and error minimization. Keywords: principal local truncation error;tolerance level;step size control;convergence;P(EC)m and P(EC)mE mode