software quality measures

8/8/2019 Software Quality Measures

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ISO/IEC 9126 SoftwareEngineering - Product Quality

Kristjn Gubjrnsson

Tlvunarfringur MSc


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Agenda

Results from part 1 (Data from 2003)

Measurement theory Quality model

Quality measurement model

Quality metrics About the assignment


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Results from part 1 Data from 2003

Data treatment High 7

Medium 4 Low 1

Inapropriate og Do not understand = 0

Normalized with respect to the number participants

Normalized with respect to the number of sub-charachteristics


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Measurement theory

Why to measure?

Communicate effectively and unambiguously

Follow and control specific objectives of aproject

Identify and correct problems rapidly

Make decisions applying multi-criteriaapproach

Justify decisions on rational basis


6/23

Comparison of models


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ISO 9126 quality model

Internal and external quality model

Overall systemquality

Functi nality Reliability Usability Eff iciency Maintainability Portability

Suitability

AccuracySecurity

Functionality

compliance

Maturity

Fault toleranceRecoverability

Reliability

compliance

Understandability

LearnabilityOperability

AttractivenessUsability

compliance

Time behaviour

Resource

utilizationEfficiency

compliance

Analysability

ChangeabilityStability

TestabilityMaintenance

compliance

Adaptability

InstallabilityCo-existance

ReplaceabilityPortability

compliance

Sub-Characteristics in blue are measured,

red Sub-Characteristics are not measured


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Functionality suitability

Sources of measurement input: Requirements specification, Evaluation report(Test report),Source code, Review report, Running software

Metric:Number of functions that are suitable for

performing the specified tasks comparing to

the number of tasks evaluated

Data elements:Problematic functions

Functions evaluated: All the functions that have

been implemented

Formula: 1 A/B

METRICS

Measurement

type Data elements Measured value R ESULT Quality defects

Count A = Numberof funct

ons

n w

ch

problems re detected

nevaluat

on 3

Count B = Numberof funct

onsevaluated

Funct

onal adequacy )

,

ssing wateringamount value, Datanot saved when

registering fertilization, wateringhistory canbe deleted


9/23


Sources of measurement input: Requirements specification(User stories), Evaluationreport(Test report), Source code, Review report , Running software

Metric: Count the number of missingfunctions detected in evaluation and

compare with the number of function

described in the requirements specification

Data elements:Missing functions: Running system

Functions in the requirements spec: All

the functions that have been specified for

delivery

Formula: 1 A/B

METRICS

Mea ement

type Data elements Measured value RESULT Quality defects

CountA = Number of missing functions

detected in ev uation 2

Count B = Number of functions described in

requirement specifications 7

Functional implementation

completeness 2)

0,71 Plant status, watering history


10/23


Sources of measurement input: Requirements specification(User stories), Evaluationreport(Test report), Source code, Review report , Running software

Metric: Count the number of incorrectlyimplemented or missing functions detected

in evaluation and compare with the total

number of functions described in the

requirements specification

Data elements:Incorrect/missing functions:

Functions in requirements specification:

All specified functions, both from current

and future iteration

Formula: 1 A/B

METRICS

Me

reme t

t

e

t eleme t

Me

re

! l e RE" U # T

$ % & lit ' ( efe ) t0

Cou1

t

A = Number ofi1 2

orrectl3

impleme1

te4

ormissi1

g fu1

ctio1

s4

etecte4

i1

evaluatio1

Cou1

t B = Number of fu1

ctio1

s4

escribe4

i1

requireme

1

t specifi

2

atio

1

s

Fu1

ctio1

alimpleme1

tatio1

coverage 3)

#DIV/0!


11/23

Functionality security

Sources of measurement input: Test specification, Test report, Requirement spec, Runningsoftware

Metric: Count the number of accesscontrollability requirements implemented

correctly as in the specifications and

compare with the number of access

controllability requirements in the

specifications.

Data elements:Number of accees control requirements

defined vs. correctly implemented

access control requirements

Formula: A/B

ME5

6 IC 7

Measurement

type Data el8 ments

Measured

value 6 E7 UL5

Quality defects

Count

9

@ NumberofA

ccess controllA

bility

requirements implemented correB

tlyA

s in the speB

ificA

tions.

CountC

@ NumberofA

ccess controllA

bility

requirements in the speB

ificA

tions

#DIV/D

!

9

ccess controllA

bility 4)


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Reliability recoverability

Sources of measurement input: Test report, Operation report , Running software

Metric:Test system in a production likeenvironment for a specified period of time

performing all user operations.

Data elements:Number of system operations.

Number of failed operations

Formula: A1 / A2

METRIC E

M F a G urF H F

nt

t I p F Data F lF H F

nt G

M F a G ur F d

P aluF REE ULT QualitQ dR fR S tT

Count

AU V

totW

lW

vW

ilW

ble cW

ses ofusers

suX X

essful softwW

reusewhenuserW

ttempt touse

Count

AY V

totW

lnumberof cW

ses ofusersW

ttempt touse the softwW

re during

observW

tion time. This is from theuser

cW

llW

ble funX

tionoperW

tion view. #DI / a !

AvW

ilW

bilitb

c

)


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Usability understandability

Sources of measurement input: Requirement spec, Design, Review report , Runningsoftware

Metric: Count the number of functionswhich are adequately described and

compare with the total number of functions

in the product.

Data elements:Total number of functions

Number of adequately described

functions

Formula: A / B

METRICS

Med e f

reme g t

th i

ep d

t d eleme g t e

Med e f

re q

r dl f e REs U t T

u v w lit x y efe t

Cou

t

A= Number of fu

ctio

s (or t

pes of

fu

ctio

s)

escribe

i

the pro

uct

escriptio

Cou

t B=

otal

umber of fu

ctio

s (or t

pes

of fu

ctio

s)#DIV/0!

Complete

ess of

escriptio

6)


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Usability understandability


Metric: Count the number of functionsthat are evident to the user and compare

with the total number of functions

Data elements:Total number of functions

Number of evident functions

Formula: A / B

ME

IC

Measurement

type Data el ments

Measured

value E UL

Quality defects

Count

Numberof fun tions (ortypes of

fun tions)evident to theuser

Count

Tot l numberof fun tions (ortypes

of fun tions)#DIV/

!

Evident fun tions

)


15/23

Usability operability


Metric: Count the number of inputitems, which check for valid data and

compare with the number of input items,

which could check for valid data

Data elements:Number of input items that can be

validated vs. number of items that are

validated

Formula: A/B

METRIC

M a ur

nt

t p Data l

nt

M a ur d

alu RE ULT Qualit d f tj

Count A k Numberofinput items whil

h chel

k

for vm

lid dm

tm

Count B k Numberofinput items whil

h could

chel

k for vm

lid dm

tm

Input vm

liditn

chel

king o )

#DI / !


16/23

Usability operability

Sources of measurement input: Test report , Running software

Metric: Observe user behavior who isoperating software, check failure cases for

user message error

Data elements:A: check for lack of messages or not

understandable

Time:

Formula: A/B

MET I S

Meas ement

ty e Dataelements

Meas ed

val e RES

T z

ality defects

Cou{

t

A =|

umber of times that the user

p}

uses for a lo{

g perio~

or

successively a{

~

repeate~

ly fails at the

s}

me operatio{

, bec}

use of the l}

c

of mess}

ge comprehe{

sio{

.

Time(mi{

utes) B = ser operati{

g time (observ}

tio{

perio~

)

Mess}

ge u{

~

ersta{

~

ability

i{

use 9)

#

IV/0!


17/23

Usability attractiveness

Sources of measurement input: Review, Running software

Metric: Review the software Data elements:

Formula:

ME

RI

Measurement

type ata elements

Measured

value RE

L

uality defects

Attractive interaction 10) ount

A = Inapropriate Alignment of items

(vertical and Horizontal), Grouping,

Use of colours, Appropriate and

reasonable sized graphics, Use of

hitespace/separators/borders,

Animation, Typography, and 3

interface.


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Efficiency time behaviour

Sources of measurement input: Test report, Running software

Metric: Start a specified task. Measurethe time it takes for the sample to complete

its operation. Keep record of each attempt

Data elements:Time: from submitting request until

request completes

Formula: T = (time of gaining the result) (time of command entry finished)

METRICS

Measurement

type Data elements Measured value RESULT Quality defects

Response time 15) Time(seconds) T = Time of gaining the result

gefa heiti = 1

flokka = 1

skr vkvun = 2

skr burargjf = 1

eya vkvunarsgu = 3


19/23

Maintainability analyzability

Sources of measurement input: Requirements spec, Review , Running software

Metric:Count the number of itemslogged in the activity log as specified and

compare it to the number of items required

to be logged.

Data elements:Number of defined logitems

Formula: A/B

METRI S

Mea u ement

ty e Data element

Mea u ed

value RES LT Quality defect

Count A= umber ofimplemented data login

items as specified confirmed in revie

Count

= umber of data items to be logged

defined in

the specifications

IV/0!

Activity recording 12)


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21/23

Comparison of models


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Verkefni

Hpalisti

Mlingin er einstaklingsverkefni Skringar merkingu mlinga

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23/23

software quality measures

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