The SCR Requirements Method in Ptolemy II (PtSCR)
Patricia Derler and Edward A. Lee
Office of Naval Research
The SCR (Software Cost Reduction) requirements method developed by NRL is a formal method for the specification and analysis of the required behavior of complex software systems. SCR has a state machine semantics and a tabular notation for specifying software requirements. This method has been applied successfully to a wide range of systems. In this project we study the SCR method with respect to (a) simulation inside Ptolemy models, (b) leveraging the tabular notation for large state machines, and (c) combination with automated requirements analysis projects. Figure 1 shows a Ptolemy simulation model that contains an SCR Model actor. Using the SCR method, the transfer of fuel between 2 tanks on an airplane is described in tabular notation.
Figure 1: Modeling fuel transfer between tanks with the SCR Method
- Heitmeyer CL, Marciniak JJ, 2002, Software Cost Reduction. Encyclopedia of Software Engineering.
- Software Cost Reduction (SCR) Toolset, http://www.nrl.navy.mil/itd/chacs/5546/SCR