Abstract: software evolution has become an important characteristic in software life cycle. SDDM（System Dynamic Development Model）,which supports software concurrent engineering ,is extended with standardization , role model , resource model and hierarchy . And by doing so, we produce the second generation SDDM，which is configurable, reusable ,supporting the standardization and software evolution modeling .

Key words: software evolution, Software process model, Petri net, SDDM

摘要： 软件演化已成为软件生存周期中最重要的形态之一。本文对支持软件并行工程的SDDM过程模型在标准化、角色模型、资源模型、层次化四个方面进行扩展，得到一个新的支持标准化的可配置、可重用的、且支持软件演化过程的第二代SDDM软件过程模型。

关键词: 软件演化, 软件过程模型, Petri网, SDDM