基于反馈控制的软件适应性需求的识别与分析

Software Adaptation Requirements Identification and Analysis Based on Feedback Control

适应性需求的识别与分析是开发自适应软件系统的基础,它将明确软件系统在运行过程中所可能面临的环境变化以及应对这些变化系统应采取的措施.但是,当前的适应性需求识别与分析方法一方面缺乏对环境的分析导致无法系统性地识别环境变化,另一方面也缺乏有效的框架来同时考虑如何应对已知的环境变化和未知的环境变化.针对这些问题,提出了基于反馈控制的适应性需求识别与分析方法.该方法将自适应软件与其作用的环境看作为一个自适应控制系统,将适应性需求的识别与分析转化为对该控制系统所应具有的反馈回路的识别与分析.通过将环境看作软件的控制对象,它不仅突出了软件的环境,同时还可以通过确定环境感知反馈回路和需求感知反馈回路来分别应对已知的环境变化和未知的环境变化.最后,用一个实例说明所提出方法的可行性.

The development of adaptive software systems is based on the adaptation requirements identification and analysis. It clarifies what changes the software will face during operation and how it needs to deal with them. However, the existing approaches pay little attention on the context analysis and lack of systematic process to identify the potential context changes. Moreover, they also lack of a framework to consider the adaptation requirements for both the known context changes and the unknown context changes. To address these issues, this paper provides an approach based on feedback control. Its basic idea is to model the adaptive software and its context as an adaptive control system, and to identify and analyze the adaptation requirements through identifying the feedback loops of such adaptive control system. By treating the context as the object to be controlled by software, it not only makes the context explicit, but also manages to define the context-aware feedback loops and the requirements-aware feedback loops to deal with the known context changes and the unknown context changes respectively. An example is used to illustrate the feasibility of the proposed approach.