This thesis considers the problem of constructing a simulation model of flow lines using JR-Net (Job Resource Relation Net) scheme and a method of converting it into an executable simulation program. Because of its easiness of model construction and good readibility, JR-Net scheme can be used as a useful modeling tool for computer simulation of flow lines. However, there exist some limitations to use it for modeling of flow lines controlled by complex control logics. Additionally, there should be an intermediate step to convert it into an executable simulation program. This thesis consists of the following three phases : (1) revision and expansion of JR-Net scheme for the purpose of enhancement of modeling power and inclusion of more real-world informations, (2) suggestion of a model specification language to express the graphical model of JR-Net in the text form, (3) construction of conversion rules for translating the model of JR-Net expressed by the proposed form into SIMAN Block Diagram model (executable simulation program). Moreover, the possibility of developing SIMAN ASPG (Automated Simulation Program Generator) using JR-Net is shown.