Model-driven round-trip engineering for IoT-based public transportation systems

Internet of Things (IoT) applications are widely employed in public transportation systems. However, the development of software for such systems—often characterized by high mobility and harsh operational environments—can be challenging and time-consuming. Model-driven engineering (MDE), which has proven effective in many domains, can also support the design and implementation of IoT-based public transportation systems (IPTSs). However, existing studies on the use of MDE techniques and approaches for the development of IPTSs mostly consider only forward engineering (FE), which limits the coverage of existing applications and cannot support synchronization between the created programs and the corresponding application models. Therefore, this study introduces a model-driven round-trip engineering (RTE) methodology that combines both FE and reverse engineering (RE) of IPTSs, in which synchronization between instance models created using a domain-specific modeling language, called DSML4PT, and the underlying code is achieved automatically through a dedicated toolchain. When using the DSML4PT language, legacy IPTS programs can be reverse engineered in an environment called RE4PT. Models extracted from existing programs can be automatically reprocessed using DSML4PT. Evaluation results clearly show that using RE4PT enables model-code synchronization and supports the integration of existing IPTS applications into the RTE, regardless of whether they were previously generated using a modeling language or even no models at all. Considering eight different real case studies, the proposed methodology reduced RE time by approximately 75%, a reduction that a paired statistical comparison of the case-level averages confirms is unlikely to be due to chance. Moreover, the qualitative assessment conducted with the participation of domain experts specifically highlighted the RE features addressing ontological, visualization, scaling, conformance and automation aspects, and also confirmed the usability and efficiency of the proposed RTE environment for IPTS development overall.