Tables 1 and 2 describe the metrics we frequently use to examine system-level characteristics of a project. Components used in the assessment include methods, signatures of the methods, and number and types of data-attribute declarations in the class. Tables 3 and 4 list the metrics used to track the design and implementation of classes. The set of metrics used in evaluation cover all constructs used in the creation of an object-oriented system. Unless otherwise stated, the measure of all metrics is an ordinal value greater than 0.0.
Derived metrics represent collective information about all classes in the system.
This characteristic can be expected of class libraries that may include functionally unrelated classes. Since these metrics represent ratios, their values are bounded between 0.0 and 1.0. Higher measures of the MFA and MAA metrics have values closer to 1.0. From an encapsulation perspective, it is desirable that no data attributes of a class be directly accessible by users of the objects. When analysis and development focus on individual classes, metrics in Tables 3 and 4 provide important information about the classes.