基于多粒度软件网络模型的软件系统演化分析

摘要

Software as a man-made system is a typical complex system,understanding its evolution contributes to bet-ter software engineering practice.In this paper,we construct software network model from a multi-granularity perspective, namely the level of package,class and feature respectively.Then we analyze the evolutions of three open-source software systems in terms of network scale,quality and structure control indicators,using complex network theory.Finally,taking Le-hman's evolution laws as the benchmarks,we compare the evolution of software networks based on multi-granularity.The results show that:(1) the evolution characteristics are varied under different granularity levels,and software network built in the level of class supports the most Lehman laws;(2) the laws of continuing growth,increasing complexity,self-regulation and conservation of familiarity are independent of the levels of granularity;(3) the impact of software evolution in the level of package on software quality is trivial,but feedback system is only supported in the case of class level.%软件系统是一类典型的人工参与的复杂系统,理解软件系统的演化规律有助于更好地指导软件工程实践.本文从包、类和特征三个粒度上构建软件系统的网络模型,利用复杂网络理论依次从网络规模、质量、结构控制三方面定量分析软件系统演化规律.以经典的Lehman演化定律为基准,对比软件系统在不同粒度下的演化差异.研究结果表明:(1)不同粒度下软件系统表现出的演化特性有所不同,其中在类粒度下效果更好;(2)持续增长、持续变化、自我调节和主体维持四项定律表现出与构建软件网络的粒度无关;(3)包粒度下系统演化对软件质量影响不大,而反馈系统定律仅在类粒度下成立.