Multi-metric prediction of software build outcomes

ness (A) Derived from overall project or for each project package Afferent Coupling (Ca) Where NoICR is the Number of Internal Class References and NoECR is the Number of External Class References. Derived from overall project or for each project package or at class (type) level. An internal class reference is where a class references another class within its own package. An external class reference is where a class references another class outside of its own package. Efferent Coupling (Ce) Total number of times a class makes references outside its own package Derived from overall project or for each project package or at class (type) level. Instability (I) Where Ce is Efferent coupling and Ca is Afferent Coupling. Derived from overall project or for each project package or at class (type) level. Normalized Distance Derived from overall project or for each project package or at class (type) level. This metric provides us data about if packages are balanced and has a good mix between abstraction and instability. Complexity metrics (Table 38) indicate the complexity of the software and can be used towards design effort and software maintenance estimation. Developed by McCabe in 1976, cyclomatic complexity measures the number of possible independent pathways through source code. In order to do this a control flow graph of the program is generated, where nodes within the graph represent a source code command, or sequence of commands and an edge that connects nodes represents the possible order of execution. For example if the source code consists of an "IF" statement of a single condition there are two possible pathways the code could be executed. One pathway is taken if the resulting value of the "IF" statement is TRUE and the other pathway if the 230 value is FALSE. Whereas if the code consists of no loops or "IF" statements, there is only one possible pathway the code could be executed, therefore there would only be one pathway for execution. Table 38 Complexity Metrics Average Block Depth Where NoM is the number of methods, NoConstr is the number of constructors and NoNC is the number of nested code Derived from overall project or for each project package, class or method. Try/catch are included in the nested count. Value is 1 if the code is not nested. High average block depth values are considered detrimental. Average Cyclomatic Complexity Where CC is the Cyclomatic Complexity. Cyclomatic complexity is calculated by the number of pathways that can be taken within the code. Where NoE is the number of edges and NoN is the number of nodes. NoConstr is the number of constructors Derived from overall project or for each project package, class or method. Cyclomatic complexity per method is the total number of pathways that the code within that method can take. Cohesion metrics provide insights into the responsibilities and design of software modules. High cohesion values indicate the reusability and readability of source code.