Prediction of Software Reliability From Residual Defects 2 - Copied

Overview

Motivation Basic Knowledge Approach Bayesian Belief Network

13/09/15 Bhaskart Roy 14CS60R25 1

Motivation


Motivation

Now Software is everywhere to make people’s life more easier , faster and secure.

High reliability is now fundamental requirement of any software. Specially for security system where any fault means to destruction of the system.


Motivation

The quality of a software is directly proportional to the reliability of the software.

So if we can predict early enough the reliability of the software then it will be more cost effective to fix the bugs.


Basic Knowledge


What is Software Reliability

The probability of failure-free software operation for a specified period of time in a specified environment .

Reliability of a software is inversely proportional to the complexity of the software.

Reliability is closely related to defects which are committed in the development phases are present in the software after test phase is completed.


Residual Defects

Residual defects are the defects that are remain in the software after testing phase is completed.

Residual defect is a direct factor to the software reliability.


Approach


Approach


Seed bugs in softwareRun test cases using

testing coverage metrics and record number of

defects found

1 2

Find Residual defects from step 1 and 2

3Take residual defects as variable and construct

Bayesian Belief Network

4

Predict reliability from Bayesian belief network

5

Bayesian Belief Network (BBN)


Definition

Bayesian Belief Network:

BBN is a composition of Directed Acyclic Graph(DAG) and Conditional Probability Distribution(CPD).DAG(Directed Acyclic Graph): DAG is a graphical structure of BBNNodes: Nodes are Random variables which may discrete or continuous.

Arcs: Arcs represents probabilistic dependencies between random variables or nodes.

Conditional Probability distribution(CPD):CPDs are a parameters of BBN.

At each dependent node conditional probability is calculated and store it in a table called Conditional Probability Table(CPT).

P() is CPD of where is set of parents of .At each independent node CPD is calculated just using prior probability of that node.

here P() = P() .

•


Bayesian Approach To Probability

Bayesian Probability : A person’s degree of belief in event X. Personal probability.

Unlike classical probability, Bayesian probabilities benefit from but do not require repeated trials - only focus on next event.


Belief Computation

Two types. Both are NP-Hard problem. Belief Revision• Model explanatory/diagnostic tasks• Given evidence, what is the most likely

hypothesis to explain the evidence? Belief Updating• Queries• Given evidence, what is the probability of

some other random variable occurring?


Belief Updating


The probability computation of a desirable node or query variable given a model is known or evidence as probabilistic inference

Find P(Q=q|E= e) Q the query variable E set of evidence variables

X1,…, Xn are network variables except Q, EP(q | e) = P(q, e)P(e)

P(q, e) =S P(q, e, x1,…, xn) x1,…, xn

Design

Right from the start, you’ll have access to beautiful, widescreen themes that you can easily change to match your style. Every theme comes with a variety of color variants that you can mix and match.New features like Merge Shapes and a color-matching Eyedropper open up new possibilities for your designs.Line up your layouts, photos, and diagrams perfectly in seconds with alignment guides and smart guides.


Impress

The improved Presenter View has new tools to keep you in control. The new Auto-Extend instantly applies the right settings for you, so you can focus on speaking instead of your display.

• Slide zoom – Help focus your audience on your ideas. Just click to zoom in and out on a specific diagram, chart or graphic.

• Slide Navigator – A feature that enables the user to visually browse for and navigate to other slides without leaving Slide Show view. Your audience only sees the slide you’re presenting.


Work Together

Edit with others from different PCs at the same time and have conversations with improved commenting. Sharing online is simple. Even if your audience doesn’t have PowerPoint, simply project to their browser with Present Online.Work together with others at the same time from different locations, whether you are using PowerPoint on your desktop or PowerPoint Online.


PowerPoint 2013

Intuitively design beautiful presentations, easily share and work together with others and give a professional performance with advanced presenting tools.

Find out more at the PowerPoint Getting Started Center(Click the arrow when in Slide Show mode)13/09/15 Bhaskart Roy 14CS60R25 18

Prediction of Software Reliability From Residual Defects 2 - Copied

Documents

Transcript of Prediction of Software Reliability From Residual Defects 2 - Copied