Assessment of the PLC Code generated with the GEMMA-GRAFCET Methodology

Industry 4.0 has fostered the digital transformation of enterprises through the retrofitting or replacement of traditional manufacturing processes with Cyber Physical Systems (CPS). Even if interoperability is paramount to correctly operate CPS, it still remains a challenge due to lack of universal standards for the management of the operational modes of CPS through the PLC code. The GEMMA-GRAFCET Methodology (GG-Methodology) was introduced as a standard approach and vocabulary to face this issue. However, the PLC code obtained from its application has not been analyzed yet. Thus, the novelty of this research work consists in the assessment of the PLC code obtained from the application of the GG-Methodology using metrics resulting from static and dynamic analysis. In comparison to a benchmark methodology, the GG-Methodology results in PLC code more complex and with larger response time, but more maintainable and with similar execution time. Given the large number of methodologies for the development of PLC code presented in the literature, authors hope that the approach adopted within this work may be utilized for generating a quantitative and objective classification that may guide the control practitioner in the methodology selection process.