SDM, SDM2, SDM/70 and Spectrum more notably evolved into system development methodologies that were based on the works of Steven Ward, Tom Demarco, Larry Constantine, Ken Orr, Ed Yourdon, Michael A. Jackson and others as well as data modeling techniques developed by Thomas Bachmann and Peter Chen.
The language was developed by Jordan Baruch specifically for the GE Medinet project (Ed Yourdon's first "Death March" project).
SA and SD were accompanied by notational methods including structure charts, data flow diagrams and data model diagrams, of which there were many variations, including those developed by Tom DeMarco, Ken Orr, Larry Constantine, Vaughn Frick, Ed Yourdon, Steven Ward, Peter Chen, and others.
Authors include Andrew Troelsen, Adam Freeman, Ed Yourdon, Matt MacDonald, Andy Budd, Rob Harrop, Dave Mark, Michael A. Banks, Keir Thomas, Malcolm Harkins, Jacob Lamm, Scott Donaldson, Peter Seibel, Bob Walsh, Rory Lewis, and Joel Spolsky.