The Problem Translator is a software program that translates functional Unified Modeling Language (fUML) activity models into a behavior-based computational problem representation language called Behavior XML (BXML). The BXML translation may then be solved by engines such as the Behavior and Analysis Engine. The translation software uniquely adds timing and richer problem-solving semantics to the standard fUML by translating activity models, augmented with timing and other constraints on events and state variables, into a tool-agnostic behavioral XML specification.

Activity models and diagrams (fUML) specify behavior without timing semantics. Because of this, execution is nondeterministic, and deterministic behavior is awkward to model. The translator fixes this problem by parsing the augmented fUML activity models and producing a BXML representation that consequently includes clear timing semantics (in addition to richer event and constraint specifications). The tools available for analyzing activity models will simulate/execute them, but other kinds of analysis (such as finding paths that meet constraints on timing or other variables) are lacking. The translation to BXML allows problems to be posed for varied kinds of analyses.

The activity model problem translator is implemented as a plug-in to the MagicDraw software developed by NoMagic. Users can specify a variety of constraints, including constraints on timing and duration of actions, and structural features of SysML (Systems Modeling Language). The translation takes into account details of the fUML standard to support (among other features) concurrent activity, nested behaviors, messaging, and modifiable projections and estimations of values.

This work was done by Maddalena M. Jackson and Bradley J. Clement of Caltech for NASA’s Jet Propulsion Laboratory. For more information, contact This email address is being protected from spambots. You need JavaScript enabled to view it.. This software is available for commercial licensing. Please contact Dan Broderick at This email address is being protected from spambots. You need JavaScript enabled to view it.. Refer to NPO-49161.

NASA Tech Briefs Magazine

This article first appeared in the November, 2015 issue of NASA Tech Briefs Magazine.

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