Temporal interference may occur in multicore processor systems due to tasks running in parallel competing for shared resources such as buses or memories. This paper presents a modelbased interference analysis based on the PHYLOG framework that intends to help in the certification process of multicore aeronautical systems. As PHYLOG does not define a clear modeling method, a refinement approach is proposed to model the system using the PHYLOG Modeling Language (PML). Our objective is to define a process that enables to build a model that is both precise and reliable so that analysis results are sound. The approach is finally validated on an industrial use case from the aerospace domain.