Software Engineering II - Topic: Software Process Metrics and Project Metrics Instructor: Dr. Jerry Gao San Jose State University URL:

Topic: Software Process and Project Metrics Software Metrics Jerry Gao Ph.D.9/2001 Measurement is fundamental to any engineering discipline, and software engineering is no exception. Measurement enable us to gain insight by providing a mechanism for objective evaluation. Why measurement? Software measurement enables managers and practitioners to improve the software process; assist in the planning, tracking, and control of a software project. to control a software project to assess the quality of the generated product. Application and usefulness: 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.

Topic: Software Process and Project Metrics Software Metrics Jerry Gao Ph.D.9/2001 Software metrics refers to a broad range of measurements for computer software. Major objectives: Software metrics are quantitative measures that enable software people to: - understand the processes by - measuring the productivity,and efficacy of a software process to improve a software process - measuring the cost, and quality of a product to assist cost estimation, quality control, project control. - check the improvement of a software process for projects. - pinpoint problem areas and plan to improve them

Topic: Software Process and Project Metrics Software Metrics Jerry Gao Ph.D.9/2001 Who does it? Software metrics are analyzed and assessed by software managers. Measures are often collected by software engineers. Why is it important? With good measurement, we can find out the current status of engineering practice for projects and products in a software process, and find the issues and solutions to improve. What are the steps? Defining a limited set of process, project, and product measures that are easy to collect Compare and analyze the current results with the past results Identify problems and improvements, generate conclusions

Topic: Software Process and Project Metrics Measures, Metrics, and Indicator Jerry Gao Ph.D.9/2001

Topic: Software Process and Project Metrics Metrics In The Process And Project Domain Jerry Gao Ph.D.9/2001 Product Technology People Customer characteristics Business conditions Development environment

Topic: Software Process and Project Metrics Software Measurement Jerry Gao Ph.D.9/2001 Direct Measures Indirect Measures Cost and Effort e.g. Lines of code(LOC) System Resource Usage (memory size, speed) Quality measurement (defect number…) Complexity Functionality Efficiency Reliability Maintainability Testability

Topic: Software Process and Project Metrics Classifications of Software Metrics Jerry Gao Ph.D.9/2001 Process MetricsProject MetricsProduct Metrics Measurement of engineering practices in an organization Measurement of engineering practice for a product (related to individual or a team) Measurement of engineering practice for a project (related to a team)

Topic: Software Process and Project Metrics Size-Oriented Metrics (LOC) Jerry Gao Ph.D.9/2001 Size-oriented software metrics are derived by normalizing quality and /or productivity measures by considering the size of the software that has been produced. Project LOC Effort $ Pp. Doc. Errors Defects People alpha 12, beta 27, gamma 20,

Topic: Software Process and Project Metrics Size-Oriented Metrics (LOC) Jerry Gao Ph.D.9/2001 Typical size-oriented metrics: Errors per KLOC (thousand lines of code) Defects per KLOC $ per LOC Page of documentation per KLOC Errors per person-month LOC per person-month $ per page of documentation

Topic: Software Process and Project Metrics Function-Oriented Metrics Jerry Gao Ph.D.9/2001 Function-oriented software metrics us a measure of the functionality delivered by the application as a normalization value. Since ‘functionality’ cannot be measured directly, it must be derived indirectly using other direct measures. Function-oriented metrics were first proposed by Albrechat, who suggested a measure called the function point. Function points are derived using an empirical relationship based on countable (direct) measures of software’s information domain and assessments of software complexity.

Topic: Software Process and Project Metrics Function-Oriented Metrics Jerry Gao Ph.D.9/2001 Measurement parameters CountSimple AverageComplex Number of user inputs x = Number of user outputs x = Number of user inquiries x 3 4 6= Number of files x = Number of external interfaces x5710= Count Total FP = count total x [ x  (Fi)] where Fi are complexity adjustment values (see Page 91).

Topic: Software Process and Project Metrics Metrics for Software Quality Jerry Gao Ph.D.9/2001 Software metrics can also be used to measure software quality based on collectable quality factors. These factors assess software from three distinct points of view: - product operation - product revision - production transition Although there are many quality indicators, here are several useful ones: Correctness, refers to the degree of a software performs its required functions correctly. Maintainability, refers to how easy a software can be changed, corrected, or extended. Integrity, can be used measure a system’s ability to withstand attacks to its security Usability, refers to the assess of a software’s user-friendless

Topic: Software Process and Project Metrics Metrics Collection, Computation, and Evaluation Jerry Gao Ph.D.9/2001 Software engineering process Software project Software product Data Collection Metrics computation Metrics evaluation indicators metrics measures