Schedulability of distributed real-time system has been studied extensively. However, due to the discrepancies the reference model used in scheduling analysis and the object-oriented model, the results cannot be easily used for distributed real-time object-oriented software development. Even if object-oriented models can be used to conduct schedulability analysis successfully, there still lacks an effective approach to validate the implementation with the design. Model-based approach alleviates the discrepancies between models of different stages and the implementation by automatically transforming models at different granularity until the code generation for the implementation from the generated design. In this paper, an approach to incorporating schedulability analysis reference diagrams into the existing framework for model-based software development will be presented. It will improve the predictability of a distributed real-time system as well as increase the capability of model refinements and code generation using the new reference diagrams and schedulability analysis results to generate code for implementing scheduling and synchronization aspects of the distributed real-time system.