Petri nets are a formal, graphical and executable modeling technique for the specification and analysis of concurrent systems and have been widely applied in computer science and many other engineering disciplines. Low level Petri nets are simple and useful for modeling control flows; however, they are not powerful to define data and system functionality. High level Petri nets were developed to support data and functionality definitions [1]. To support the practical applications of Petri nets formalism, tools for designing and executing Petri nets are necessary. Although there are many existing tools for supporting low level Petri nets [5], few tools are available for high level Petri nets. There is especially a lack of tools to support high level Petri net notation proposed in the international standard [1]. In this paper, we present a tool, called PIPE+, to support a subset of high level Petri nets proposed in [1]. PIPE+ is built upon an existing low level Petri net tool PIPE (Platform Independent Petri Net Editor) [2]. This paper describes the functionality of PIPE+ as well as illustrates the process of extending PIPE, which provides helpful insights for others to create Petri net tools suit their own needs. Furthermore, PIPE+ is an open source tool and thus is available for various enhancements from worldwide research community.
