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CHAPTER 4 SOFTWARE PROCESS AND PROJECT METRICS 107

process entities and attributes that are relevant to the subgoal are identified and mea-
surement goals associated with them are delineated.
The SEI [PAR96] provides detailed guidance for steps 6 through 10 of its goal-
driven measurement approach. In essence, a process of stepwise refinement is applied
in which goals are refined into questions that are further refined into entities and
attributes that are then refined into metrics.

4.10 SUMMARY
Measurement enables managers and practitioners to improve the software process;
assist in the planning, tracking, and control of a software project; and assess the qual-
ity of the product (software) that is produced. Measures of specific attributes of the
process, project, and product are used to compute software metrics. These metrics
can be analyzed to provide indicators that guide management and technical actions.
Process metrics enable an organization to take a strategic view by providing insight
into the effectiveness of a software process. Project metrics are tactical. They enable
a project manager to adapt project work flow and technical approach in a real-time
manner.
Both size- and function-oriented metrics are used throughout the industry. Size-
oriented metrics use the line of code as a normalizing factor for other measures such
as person-months or defects. The function point is derived from measures of the infor-
mation domain and a subjective assessment of problem complexity.
Software quality metrics, like productivity metrics, focus on the process, the proj-
ect, and the product. By developing and analyzing a metrics baseline for quality, an
organization can correct those areas of the software process that are the cause of
software defects.
Metrics are meaningful only if they have been examined for statistical validity. The
control chart is a simple method for accomplishing this and at the same time exam-
ining the variation and location of metrics results.
Measurement results in cultural change. Data collection, metrics computation,
and metrics analysis are the three steps that must be implemented to begin a met-
rics program. In general, a goal-driven approach helps an organization focus on the
right metrics for its business. By creating a metrics baseline—a database containing
process and product measurements—software engineers and their managers can
gain better insight into the work that they do and the product that they produce.

REFERENCES
[ALA97] Alain, A., M. Maya, J.M. Desharnais, and S. St. Pierre, “Adapting Function
Points to Real-Time Software,” American Programmer, vol. 10, no. 11, November
1997, pp. 32–43.