In this paper, a partitioned coupling analysis system is developed for a numerical simulation of 3-dimensional fluid–structure interaction (FSI) problems, adopting an incompressible smoothed particle hydrodynamics (SPH) method for fluid dynamics involving free surface flow and the finite element method (FEM) for structural dynamics. A coupling analysis of a particle-based method and a grid-based method has been investigated. However, most of these are developed as a function-specific application software, and therefore lack versatility. Hence, to save cost in software development and maintenance, the open source software is utilized. Especially, a general-purpose finite element analysis system, named ADVENTURE, and a general-purpose coupling analysis platform, named REVOCAP_Coupler, are employed. Moreover, techniques of an interface marker on fluid–structure boundaries and a dummy mesh for fluid analysis domain are adopted to solve the problem that the REVOCAP_Coupler performs to unify two or more grid-based method codes. To verify a developed system, the dam break problem with an elastic obstacle is demonstrated, and the result is compared with the results calculated by the other methods.