This paper is concerned with the numerical solution of systems of blocked nonlinear equations arising in the solution of multidisciplinary analysis (MDA) problems. We consider the case where individual discipline solvers/simulators are given and are iterative methods. Thus, an MDA solver consists of an outer iteration for the solution of the system of blocked nonlinear equations and of inner iterations in the discipline simulators. We show how the control of the truncation of the inner iterations can be effectively used to accelerate the overall iteration. The key is the interpretation of the outer iteration with inexact inner iteration as an iteration of a related system with the same solution as the MDA problem.