Multi-agent systems (MASs) have become an important topic in distributed systems research. These distributed multi-agent systems call for special software modeling methods that explicitly support key system properties such as resource constraints and control of conflicts. Although there have been some system modeling techniques to support MASs design and automatic analysis, most state-of-the-art techniques have not distinguished potential conflicts from real conflicts during the design stage. To solve this problem, we define a new concept, called "potential arcs," which is integrated into colored Petri net modeling to support the modeling of MASs. We present a modeling methodology based on the potential arc concept and illustrate the methodology with a case study, including some associated model analysis.

Automated testing typically uses specifications to drive the generation of test inputs and/or the checking of program outputs. Many software systems have structurally complex inputs that cannot be adequately described using simple formalisms such as context-free grammars. In order to generate such inputs, many automated testing environments require the user to express the structure of the input using an unfamiliar formal notation. This raises the cost of employing automated testing, thereby offsetting the benefits gained. We present yagg (yet another generator-generator), a tool that allows the programmer to specify the input using a syntax very similar to that of LEX and YACC, widely used scanner and parser generators. yagg allows the user to bound the input space using several different techniques, and generates an input generator that systematically enumerates inputs. We evaluate the ease of use and performance of the tool relative to a model checker-based generator used in previous research. Our experiences indicate that yagg generators can be somewhat slower, but that the ease-of-use afforded by the familiar syntax may be attractive to users.