In 1966, Hermann Dommel was invited to BPA from Germany to work on the development of a software named Electromagnetic Transients Program (EMTP).
This project was directed by W. F. Tinney whose fundamental contributions to the solution of sparse matrices enabled EMTP and other packages to simulate large power systems.
W. Scott Meyer collaborated with various researchers & experts including A. Ametani, Vladimir Brandwajn, Laurent Dubé, José R. Marti, Adam Semlyen.
The list included: ABB, AEP, CEA, CRIEPI, EDF, EPRI, Hydro-Québec, Ontario Hydro, US Bureau of Reclamation, Western Area Power Administration.
In 1984 BPA left the DCG and W. Scott Meyer continued independently and personally developing with the existing EMTP code under the new name EMTP-ATP in his free time.
In 1996 J. Mahseredjian proposed to the DCG to abandon the old EMTP code and to rewrite it from scratch using modern programming languages, and latest numerical methods.
J. Mahseredjian worked later with a small team of developers, including mainly S. Dennetière, O. Saad, C. Dewhurst and Laurent Dubé, to deliver the new commercial version of EMTP, in 2003.
This new commercial EMTP code introduced several major improvements in graphical user interface, programming practices and numerical methods.