Environment Portability and Extensibility Measures.

Abstract : To validate the thesis that environments based on abstract interfaces provide enhanced portability and extensibility, the author decided to compare his environment against existing non-interface based environments. To do this, he needed two metrics: one to measure portability, and the other to measure extensibility. These metrics has to be applicable to the environment as a whole and had to exhibit the following characteristics. First, the metrics had to be objective: given sufficient knowledge of the system, an individual should be able to computer only one possible measurement. Second, the metric must be applicable given only the environment design documentation and source code, thus ensuring the metrics are based solely on the characteristics of the software.