OO Metrics in Practice
David P. Darcy, Chris F. Kemerer · IEEE Software · 2005
While it has long been recognized that software process improvement requires measuring both the process and its performance, experience has also shown that few universal metrics exist. The most effective measurement tools are specialized to some aspect of the task or domain being measured. The metrics as measures of code have often been related to external factors, such as software quality in the sense of defects. Software metrics studies often use single snapshots of a software project. Examining a project over a longer time frame allows consideration of other software quality facets, such as reuse and maintainability.