STQA_Session_10

In this session, you will learn to:
Define test metrics Identify the significance of metrics in testing Identify the types of test metrics Determine the effect of test metrics on management decisions
Software Testing and Quality Assurance
Chapter 10 Quantitative Measures in Testing
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Software Testing and Quality Assurance
Objectives
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Software Testing and Quality Assurance
Metrics Unique to Test
The common metrics unique to testing include:
Mean Time to Failure (MTTF): It is a measure of reliability and calculates the average time before the first failure. It provides the average time from one failure to the next during a test operation on a software project. This is the average time that the products are expected to operate at a particular stress level before failure. MTTF can be computed as follows: 1. Define the period over which the MTTF is to be calculated as starting tiem,t2 and ending time ,t3. 2. Locate the latest failure earlier than t2 and fine the time, t1, at which this failure occurred. 3. Locate the earliest failure later than t3 and fine the time, t4, at which it occurred, meaning the two failures nearest to the period but outside the period in question.
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Software Testing and Quality Assurance
Metrics Unique to Test
The common metrics unique to testing include:
Defect Removal Efficiency (DRE): It is the measure of defects before the delivery of software. It provides benefits at both the project level as well as the process level of the software development process. DRE is calculated as percentage of the defects identified and corrected internally with respect to the total defects in the complete project life cycle. DRE=(Total numbers of defects found during development (before delivery)) / (Total number of defects found during development (before delivery) + Total numbers of defects found after delivery) The DRE indicates the defect filtering ability of the testing processes.
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Software Testing and Quality Assurance
Test Metrics
Metrics are standards of measurement and are crucial to the testing life cycle. Test metrics are used to measure the effectiveness of software testing. Metrics are the best way to know whether a process is under control and is performing as desired.
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Software Testing and Quality Assurance
Need for Test Metrics
Test metrics are used to plan the number and types of tests on a software product. Test metrics are used to estimate various components such as test coverage for given components of a software project.
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Software Testing and Quality Assurance
Metrics Unique to Test
The common metrFra bibliotekcs unique to testing include:
Defect Density (DD): It is the measure of all the found defects per size of software entity being measured. This measure is expressed in the standard measurement terms for the software product. These can be in Line of code (LOC) or Function Points (FPs). The size is used to normalize the measurements to allow comparisons between different software entities, such as the defects found in a module or release of a software product. DD= Number of known Defects / Size (in LOC or FP) DD helps the management in comparing the relative number of defects found in the components of the software product.
Allocation of dedicated resources The project planning techniques should be used to plan the number and types of resources needed to achieve a successful measurement effort. Use of automated tools Focus of the test tracking processes should be on the testing goals The focus of the testing processes must always be set on the goals set by the management of the organization.
Basis for estimation Test metrics can serve as a basis for estimation for types of tests and the test effort required for the software. Status reporting The testing status of a software development project can be measured based upon various components such as the number or percentage of test cases executed, requirements tested, modules tested, and business functions tested. Flag actions Some test metrics guide the management on when to flag certain action in the software development process. Identification of risks Test metrics collected from various parts of a software development project indicate the parts of the project that can be risky and require careful planning.
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Software Testing and Quality Assurance
Gathering Test Metrics
Gathering test metrics with the correct framework is crucial for a successful test metrics collection program. While gathering test metrics, the following aspects must be ensured:
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Software Testing and Quality Assurance
Types of Test Metrics
There are various types of test metrics that can be gathered in a software development project. Most projects need measures of quality, resources, time, and size. To analyze the product or process effectiveness, the results of these quality measures are evaluated against certain standards or benchmarks an organization creates.
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Software Testing and Quality Assurance
Need for Test Metrics The various purposes for which test metrics are used in an organization are: