Cyber physical systems (CPSs) are complex systems whose performance depends on the interactions between heterogeneous subsystems, the external environment, and the interrelation between the natural systems and its cyber-physical augmentations. Any fault that occurs during these diverse and interrelated interactions may cause failure or a malfunction of the entire system. The traditional multi-aspects modeling techniques developed for analyzing complex system performance can to some extent fundamentally be used in the analysis of CPSs. The problem, however, is that these modeling techniques do not consider the consequences of the integration of natural systems and cyber-physical augmentations. In this article, we propose a novel dual-aspect modeling technique that integrates natural and CPSs functional systems. This modeling technique includes natural systems, such as plants and humans as integral parts of the system, and therefore allows us to study their interactions, influences and effects. A cyber-physical greenhouse case study is presented to demonstrate the applicability of the proposed modeling technique. The proposed dual-aspect modeling technique will be used in the subsequent stages of our research to analyze and understand the interactions between natural systems and CPS augmentations with a view to identify influential factors of failure in system operation as well as the cause and types or modes failures.