1. Measurement What is it and why do it? 2/23/2019
SWEN 5430 Software Metrics

2. Measurement in every day life
Measurement is the process by which numbers or symbols are assigned to attributes of entities in the real world in such a way as to describe them according to clearly defined rules.
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SWEN 5430 Software Metrics

3. Measurement in every day life (continued)
Measurement captures information about attributes of entities.
Entity is an object or an event in the real world
Attribute is a feature or property of an entity
Measurement is a process whose definition is far form clear cut
Measurement has different interpretations
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SWEN 5430 Software Metrics

4. Measurement in every day life (continued)
“What is not measurable make measurable”
Galileo Galilei ( )
Two kinds of quantification Measurement and Calculation
Measurement is a direct quantification
Calculation is an indirect quantification
Use direct and indirect to distinguish Measurement from Calculation
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SWEN 5430 Software Metrics

5. Measurement in Software Engineering
Software Engineering describes the collection of techniques that apply an engineering approach to the construction and support of software products
Managing costing planning
Modeling analyzing specifying
Designing implementing
Testing maintaining
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SWEN 5430 Software Metrics

6. Measurement in Software Engineering (continued)
Neglect of measurement in SWEN
Engineering uses methods based on models and theories.
Once a Scientific method suggests the validity of a model or theory scientists uses measurement to apply the theory to practice
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SWEN 5430 Software Metrics

7. Measurement in Software Engineering (continued)
Neglect of measurement in SWEN
For most SW development projects engineers
Fail to set measurable targets for SW projects.
Fail to understand and quantify the component costs.
Don’t quantify or predict the quality of the products.
Allow untested methodology to try another newly developed technology.
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SWEN 5430 Software Metrics

8. Measurement in Software Engineering (continued)
Gilb’s Principle of Fuzzy Targets:
“Projects without clear goals will not achieve their goals clearly.”
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SWEN 5430 Software Metrics

9. Measurement in Software Engineering (continued)
Objectives for SW Measurement
“you cannot control what you cannot measure” (DeMarco, 1982)
How can a manager or an engineer tell if the project is succeeding if they have no measure of it’s success?
The managers & engineer must control and run the projects.
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SWEN 5430 Software Metrics

10. Measurement in Software Engineering (continued)
Objectives for SW Measurement Manager prospective
What does the process cost?
How productive is the staff?
How good is the code being developed
Will the user be satisfied with the product
How can the process be improved
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SWEN 5430 Software Metrics

11. Measurement in Software Engineering (continued)
Objectives for SW Measurement Engineers prospective
Are the requirements testable?
Have we found all the faults?
Have we met our product, process and resource (PPR ) goals?
Can we measure attributes of this PPR to make predictions for future?
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SWEN 5430 Software Metrics

12. Measurement in Software Engineering (continued)
Measurement for understanding, control and improvement
Measures help to understand what is happening during development and maintenance
Measurement allows the control of the PPR
Measurement encourages the improvement of the PPR
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SWEN 5430 Software Metrics

13. The scope of software metrics
Software metrics activities involves many methods of software measurement collection processes.
Cost and effort estimation
Productivity measures and models
Data Collection
Quality models and measures
Reliability models
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SWEN 5430 Software Metrics

14. The scope of software metrics (continued)
Software metrics activities involves many methods of software measurement collection processes.
Performance evaluation and models
Structural and complexity metrics
Capability-maturity assessment
Management by metrics
Evaluation of methods and tools
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SWEN 5430 Software Metrics

15. Summary
Measurement is essential for good Software Engineering Practices.
Other engineering disciplines suggest that measurement must play a role in SWEN.
SW measurement is a diverse collection of fringe topics (SW metrics) that range from models for predicting SW project costs at the specific stages of the SW life cycle.
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SWEN 5430 Software Metrics

16. Summary (continued)
Measurement is essential for good Software Engineering Practices.
SW metrics engineering probably lacks the rigor applies to other engineering disciplines.
Managers & Engineers must have specific, clearly stated objectives for measurement.
Must research and apply new measurement methodology for attributes of interest.
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SWEN 5430 Software Metrics