metrics and project management

8/3/2019 Metrics and Project Management

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Metrics

-S.Jain


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Some definitions

Measure- quantitative indication of extent,amount, dimension, capacity, or size ofsome attribute of a product or process.

Measurement is the key element of anyengineering process

E.g., Number of errors


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Cont

Metric- quantitative measure of degree towhich a system, component or processpossesses a given attribute. A handle or

guess about a given attribute. E.g., Number of errors found per person

hours expended

It could be used to measurecharacteristics of a software system or thesoftware development process .


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Why Metrics ?

To determine the quality of the currentproduct or process

To predict qualities of a product/process

To improve quality of a product/process


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Types of Metrics

Products Explicit results of software development activities

Deliverables, documentation, by products

Processes Activities related to production of software

Resources Inputs into the software development activities

hardware, knowledge, people


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Process metrics

Helps to gain insight into the efficiency ofthe software process and the projects.

Basic quality and productivity data arecollected, analyzed, compared againstpast averages, and assessed to determineif the quality and productivity has

improved.

Helps to know the problem areas.


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Product Metrics

Helps in gaining insight into the designand construction of the software

It focuses on specific attributes of software

engineering work products and arecollected as technical tasks are beingconducted.

Product Metrics are computed from thedata collected from the design models,source code and test cases.


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Types of Measures

Direct Measures (internal attributes)

Cost, effort, LOC, speed, memory

Indirect Measures (external attributes)

Functionality, quality, complexity, efficiency,reliability, maintainability


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Size Oriented Metrics

Size oriented metrics are derived by normalizingquality and/or productivity measures byconsidering the size of the project. The measurecan be -

LOC -Lines Of CodeKLOC -1000 Lines Of CodeSLOCStatement Lines of Code (ignore

whitespace)

Typical Measures: Errors/KLOC, Defects/KLOC, Cost/LOC,

Documentation Pages/KLOC


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LOC metrics are -

Easy to use

Easy to compute

Language and programmer dependent

Cannot accommodate nonprocedurallanguages


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Function Oriented Metrics

Use a measure of the functionality deliveredby the application as a normalization value.

Most widely used is function point (FP)metric. Computation is based oncharacteristics of the softwares information

domain and complexity.


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Function Point Metrics

FP is programming language independent(i.e. conventional as well as nonproceduallanguages).

It is based on data that are more likely tobe known early in the evolution of theproject .


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Object Oriented Metrics

Conventional software project metrics(LOC and FP) can be sued to estimateobject oriented software products.

These metrics do not provide properschedule and effort estimation that arerequired in evolutionary or incremental

process.


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Set of Object Oriented Metricsas suggested by Lorenz and Kidd

Number of scenario scripts

It is directly correlated to the size of application and to

the number of test cases that must be developed.

Number of key classes

It shows the amount of effort required to develop thesoftware and also indicated the potential amount ofreuse to be applied during system development.

Number of support classes

It shows the amount of effort required to develop thesoftware and also indicated the potential amount of

reuse to be applied during system development.


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Cont

Average number of support classes perkey class

Lorenz and Kidd have estimated that GUI applications

have two to three times and Non GUI applications haveone to two times the number of support classes as keyclasses.

Number of subsystemsAfter identification of subsystems, it is easier to lay out areasonable work schedule


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Use-Case Oriented Metrics

Use-case describe user-visible functionsand features that are basic requirementsfor a system.

The number of use-case is directlyproportional to the size of application inLOC and to the number of test cases thatwill have to be designed.

Since use case can be created at differentlevels of abstraction, there is no standardsize for a use-case.


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Web Engineering Project Metrics

Some measures that can be collected are

Number of Static Web Pages

Measure provides an indication of overall size of the

application and the efforts required to develop it

Number of dynamic web pagesProvides an indication of the overall size of theapplication and the efforts required to develop it

Number of internal page links

As the number of page links increases, the effortexpanded on navigational design and construction also

increases.

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