Interactive web interfaces modeling, simulation and analysis using Colored Petri Nets

Interaction modeling is a relevant activity during software development processes. Created relying on Petri Nets theory and aiming to represent discrete time events, Colored Petri Nets (CPNs) are a graphical formal language developed and widely employed for system modeling. While traditional CPNs only have elements with ordinary stylization and behaviors, in this article we explore the key ideas behind Web Interaction Modeling Using Colored Petri Nets (wiCPN), a modeling style developed with focus on representing Web interactions as an incremental improvement of CPNs. We review wiCPN’s refinements over CPNs and the modeling of the Web interface of Classroom eXperience (CX), a ubiquitous educational platform, thus verifying the model’s properties to ensure it was able to represent the different access levels among its users and how wiCPN displayed suitability to comprehend this requirement on the generated model. We have also improved the originally developed model with the modification of elements to make it finite and fully analyzable. Also, we added temporization capabilities to the model and ran corresponding user simulation to observe the average time that users with different roles tend to spend during interactions. We compared wiCPN results with Unified Modeling Language (UML) Activity and Use Case diagrams, observing, as outcomes, that the generated model represented CX’s interactive flow correctly and maintained a concise notation—a single wiCPN diagram was sufficient to depict the same interactive flow that, in UML, would require several diagrams, something that could overload the design team in actual software development scenarios. We also included new user experiments comprising qualitative results from experts. Finally, we created a reachability graph for the new model and generated a full state space report, analyzing Petri Nets properties such as boundedness, liveness and home marking.