This work presents the interrelation of software engineering and computational semiotics applied to establish a new procedure to design and specify electromagnetic simulator, contributing to define a possible solution for a complex usability problem for engineers and scientists who wants to use this type of computational approach. It is justified by the large number of Physical properties necessary to perform any numerical simulation, specially, for telecommunications. In this work the main integrated techniques are Service Oriented Architecture (SOA), Nielsen principles with severity levels, signs representations from computational semiotics and a cognitive route technique, and they were integrated to establish a procedure to design and test this type of numerical simulator, allowing to identify some breakpoints in these simulator projects before its delivery. These integrations present successful results, eliminating interface errors and failures, improvements in human-computer interactions and, consequently, it contributes perform a faster procedure to develop an interface for an electromagnetic simulator, which can be applied in science and didactic procedures. © 2012 IEEE.