istqb chapter2

7/28/2019 ISTQB Chapter2

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Testing in the Lifecycle

1 Principles 2 Lifecycle

4 Dynamic testtechniques

3 Static testing

5 Management 6 Tools

Software Testing

ISTQB / ISEB Foundation Exam Practice

Chapter 2


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Contents

Models for testing, economics of testing

High level test planning

Component Testing

Integration testing in the small

System testing (non-functional and functional)

Integration testing in the large

Acceptance testing

Maintenance testing

Lifecycle

1 2 3

4 5 6



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V-Model: test levels

Integration Testing

in the Small

Integration Testing

in the Small

Integration Testing

in the Large

Integration Testing

in the Large

System

Testing

System

Testing

Component

Testing

Component

Testing

AcceptanceTesting

AcceptanceTesting

Code

Code

Design

Specification

Design

Specification

System

Specification

System

Specification

Project

Specification

Project

Specification

BusinessRequirements



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Tests



Tests

Project

Specification

Project

Specification

TestsSystem

Specification

System

Specification

Tests

Design

Specification

Design

SpecificationTests

Code

Code

V-Model: late test design

Integration Testing

in the Small

Integration Testing

in the Small

Integration Testing

in the Large

Integration Testing

in the Large

System

Testing

System

Testing

Component

Testing

Component

Testing

AcceptanceTesting

AcceptanceTesting

Design

Tests?

We dont havetime to design

tests early


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Early test design

test design finds faults

faults found early are cheaper to fix

most significant faults found first

faults prevented, not built in

no additional effort, re-schedule test design

changing requirements caused by test design

Early test design helps to build quality,

stops fault multiplication

Early test design helps to build quality,

stops fault multiplication


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Experience report: Phase 1

Phase 1: Plan2 mo 2 mo

dev test

test150 faults

1st mo.50 faults

usersnothappy

Quality

fraught, lots of dev overtime

Actual

"has to go in"but didn't work


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Experience report: Phase 2

Source: Simon Barlow & Alan Veitch, Scottish Widows, Feb 96

Phase 2: Plan2 mo 6 wks

dev test

test

50 faults

1st mo.

0 faultshappyusers!

Quality

smooth, not much for dev to do

Actual

acc test: fullweek (vs half day)

on time

Phase 1: Plan2 mo 2 mo

dev test

test

150 faults

1st mo.

50 faults

users

nothappy

Quality

fraught, lots of dev overtime

Actual

"has to go in"but didn't work

Phase 2: Plan2 mo 6 wks

dev test

test50 faults

1st mo.0 faults

happyusers!

Quality

smooth, not much for dev to do

Actual

acc test: fullweek (vs half day)

on time


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VV&T

Verification the process of evaluating a system or component tothe process of evaluating a system or component to

determine whether the products of the givendetermine whether the products of the given

development phase satisfy the conditions imposeddevelopment phase satisfy the conditions imposed

at the start of that phase [BS 7925-1]at the start of that phase [BS 7925-1] Validation

determination of the correctness of the products ofdetermination of the correctness of the products ofsoftware development with respect to the usersoftware development with respect to the user

needs and requirements [BS 7925-1]needs and requirements [BS 7925-1]

Testing

the process of exercising software to verify that itthe process of exercising software to verify that itsatisfies specified requirements and to detect faultssatisfies specified requirements and to detect faults


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Verification, Validation and Testing

Verification

Validation

TestingAnyAny


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V-model exercise


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The V Model - Exercise

DS

FDBuild

Components

Build

UnitsTD

Build

System

Code

Build

AssemblageVD

System

Test

Integration

TestReview FD

Review TD

TUT

FUT

Review DS

Review VD

Assembly

Test

Exceptions:

Conversion TestFOS: DN/Gldn


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How would you test this spec?

A computer program plays chess with one

user. It displays the board and the pieces on

the screen. Moves are made by dragging

pieces.


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Testing is expensive

Compared to what?

What is the cost of NOT testing, or of faults

missed that should have been found in test?

- Cost to fix faults escalates the later the fault is foundCost to fix faults escalates the later the fault is found- Poor quality software costs more to usePoor quality software costs more to use

users take more time to understand what to dousers take more time to understand what to do

users make more mistakes in using itusers make more mistakes in using it

morale suffersmorale suffers

=> lower productivity=> lower productivity Do you know what it costs your organisation?


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What do software faults cost?

Have you ever accidentally destroyed a PC?

- knocked it off your desk?knocked it off your desk?

- poured coffee into the hard disc drive?poured coffee into the hard disc drive?

- dropped it out of a 2nd storey window?dropped it out of a 2nd storey window?

How would you feel?

How much would it cost?


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Hypothetical Cost - 1

(Loaded Salary cost: 50/hr)Fault Cost Developer User

700 50

- detect ( .5 hr) 25

- report ( .5 hr) 25

- receive & process (1 hr) 50

- assign & bkgnd (4 hrs) 200

- debug ( .5 hr) 25

- test fault fix ( .5 hr) 25

- regression test (8 hrs) 400


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Fault Cost Developer User

700 50

- update doc'n, CM (2 hrs) 100

- update code library (1 hr) 50- inform users (1 hr) 50

- admin(10% = 2 hrs) 100

Total (20 hrs) 1000


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Fault Cost Developer User

1000 50(suppose affects only 5 users)

- work x 2, 1 wk 4000

- fix data (1 day) 350

- pay for fix (3 days maint) 750

- regr test & sign off (2 days) 700

- update doc'n / inform (1 day) 350

- double check + 12% 5 wks 5000- admin (+7.5%) 800

Totals 1000 12000


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Cost of fixing faults

Req UseDes Test

1

10

1000

100


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How expensive for you?

Do your own calculation

- calculate cost of testingcalculate cost of testing

peoples time, machines, toolspeoples time, machines, tools

- calculate cost to fix faults found in testingcalculate cost to fix faults found in testingcalculate cost to fix faults missed by testingcalculate cost to fix faults missed by testing

Estimate if no data available

- your figures will be the best your company has!your figures will be the best your company has!

(10 minutes)

Lif l


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Contents

Lifecycle

1 2 3

4 5 6



Component Testing



Integration testing in the largeAcceptance testing

Maintenance testing



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(Before planning for a set of tests)

set organisational test strategy

identify people to be involved (sponsors,

testers, QA, development, support, et al.)

examine the requirements or functionalspecifications (test basis)

set up the test organisation and infrastructure

defining test deliverables & reporting

structure

See: Structured Testing, an introduction to TMap, Pol & van Veenendaal, 1998


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What is the purpose of a high level test plan?

- Who does it communicate to?Who does it communicate to?

- Why is it a good idea to have one?Why is it a good idea to have one?

What information should be in a high level testplan?

- What is your standard for contents of a test plan?What is your standard for contents of a test plan?

-Have you ever forgotten something important?Have you ever forgotten something important?

- What is not included in a test plan?What is not included in a test plan?


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Test Plan 1

1 Test Plan Identifier

2 Introduction

- software items and features to be testedsoftware items and features to be tested

- references to project authorisation, project plan, QAreferences to project authorisation, project plan, QAplan, CM plan, relevant policies & standardsplan, CM plan, relevant policies & standards

3 Test items

-test items including version/revision leveltest items including version/revision level

- how transmitted (net, disc, CD, etc.)how transmitted (net, disc, CD, etc.)

- references to software documentationreferences to software documentationSource: ANSI/IEEE Std 829-1998, Test Documentation


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Test Plan 2

4 Features to be tested

- identify test design specification / techniquesidentify test design specification / techniques

5 Features not to be tested

- reasons for exclusionreasons for exclusion


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Test Plan 3

6 Approach- activities, techniques and toolsactivities, techniques and tools

- detailed enough to estimatedetailed enough to estimate

- specify degree of comprehensiveness (e.g.specify degree of comprehensiveness (e.g.

coverage) and other completion criteria (e.g. faults)coverage) and other completion criteria (e.g. faults)

- identify constraints (environment, staff, deadlines)identify constraints (environment, staff, deadlines)

7 Item Pass/Fail Criteria

8 Suspension criteria and resumption criteria- for all or parts of testing activitiesfor all or parts of testing activities

- which activities must be repeated on resumptionwhich activities must be repeated on resumption


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Test Plan 4

9 Test Deliverables

- Test planTest plan

- Test design specificationTest design specification

- Test case specificationTest case specification

- Test procedure specificationTest procedure specification

- Test item transmittal reportsTest item transmittal reports

- Test logsTest logs- Test incident reportsTest incident reports

- Test summary reportsTest summary reports


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Test Plan 5

10 Testing tasks

- including inter-task dependencies & special skillsincluding inter-task dependencies & special skills

11 Environment

- physical, hardware, software, toolsphysical, hardware, software, tools

- mode of usage, security, office spacemode of usage, security, office space

12 Responsibilities

- to manage, design, prepare, execute, witness, check,to manage, design, prepare, execute, witness, check,resolve issues, providing environment, providingresolve issues, providing environment, providing

the software to testthe software to test


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Test Plan 6

13 Staffing and Training Needs 14 Schedule

- test milestones in project scheduletest milestones in project schedule

- item transmittal milestonesitem transmittal milestones

- additional test milestones (environment ready)additional test milestones (environment ready)

- what resources are needed whenwhat resources are needed when

15 Risks and Contingencies

- contingency plan for each identified riskcontingency plan for each identified risk 16 Approvals

- names and when approvednames and when approved

Lifecycle


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Contents



Component Testing




Maintenance testing

y

1 2 3

4 5 6



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Component testing

lowest level

tested in isolation

most thorough look at detail

- error handlingerror handling

- interfacesinterfaces

usually done by programmer

also known as unit, module, program testing


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Component test strategy 1

specify test design techniques and rationale

- from Section 3 of the standard*from Section 3 of the standard*

specify criteria for test completion and

rationale- from Section 4 of the standardfrom Section 4 of the standard

document the degree of independence for test

design

- component author, another person, from differentcomponent author, another person, from different

section, from different organisation, non-humansection, from different organisation, non-human

*Source: BS 7925-2, Software Component Testing Standard


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Component test strategy 2

component integration and environment

- isolation, top-down, bottom-up, or mixtureisolation, top-down, bottom-up, or mixture

- hardware and softwarehardware and software

document test process and activities- including inputs and outputs of each activityincluding inputs and outputs of each activity

affected activities are repeated after any fault

fixes or changes

project component test plan

- dependencies between component testsdependencies between component tests


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Component

Test DocumentHierarchy

ComponentTest Strategy

ProjectComponentTest Plan

ComponentTest

Specification

ComponentTest Plan

Component

Test Report

Source: BS 7925-2,

Software Component

Testing Standard,

Annex A


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Component test process

Checking for

Component

Test Completion

Component

Test Planning

Component

Test Specification

Component

Test Execution

Component

Test Recording

BEGIN

END


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Component

Test Planning

Component

Test Specification

Component

Test Execution

Component

Test Recording

Checking for

Component

Test Completion

BEGIN

END

Component test planning

- how the test strategy andproject test plan apply to

the component under test

- any exceptions to the strategy

- all software the component

will interact with (e.g. stubs

and drivers


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Component

Test Planning

Component

Test Specification

Component

Test Execution

Component

Test Recording

Checking for

Component

Test Completion

BEGIN

END

Component test specification

- test cases are designed

using the test case design

techniques specified in the

test plan (Section 3)

- Test case:

objective

initial state of component

inputexpected outcome

- test cases should be

repeatable


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Component

Test Planning

Component

Test Specification

Component

Test Execution

Component

Test Recording

Checking for

Component

Test Completion

BEGIN

END

Component test execution- each test case is executed

- standard does not specify

whether executed manually

or using a test execution

tool


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Component

Test Planning

Component

Test Specification

Component

Test Execution

Component

Test Recording

Checking for

Component

Test Completion

BEGIN

END

Component test recording

- identities & versions ofcomponent, test specification

- actual outcome recorded &

compared to expected outcome

- discrepancies logged

- repeat test activities to establishremoval of the discrepancy

(fault in test or verify fix)

- record coverage levels achieved

for test completion criteria

specified in test plan

Sufficient to show test

activities carried out


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Component

Test Planning

Component

Test Specification

Component

Test Execution

Component

Test Recording

Checking for

Component

Test Completion

BEGIN

END

Checking for component

test completion

- check test records against

specified test completion

criteria

- if not met, repeat test

activities

- may need to repeat test

specification to design testcases to meet completion

criteria (e.g. white box)

Also a measurement


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Test design techniques

Black box

- Equivalence partitioningEquivalence partitioning

- Boundary value analysisBoundary value analysis

- State transition testingState transition testing

- Cause-effect graphingCause-effect graphing

- Syntax testingSyntax testing

- Random testingRandom testing

How to specify other

techniques

White box

- Statement testingStatement testing

- Branch / Decision testingBranch / Decision testing

- Data flow testingData flow testing

- Branch condition testingBranch condition testing

- Branch conditionBranch condition

combination testingcombination testing

- Modified conditionModified condition

decision testingdecision testing

- LCSAJ testingLCSAJ testing

= Yes

= No

technique?

Lifecycle


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Contents



Component Testing




Maintenance testing

1 2 3

4 5 6


Integration testing


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Integration testing

in the small

more than one (tested) component

communication between components

what the set can perform that is not possible

individually non-functional aspects if possible

integration strategy: big-bang vs incremental

(top-down, bottom-up, functional)

done by designers, analysts, or

independent testers

Bi B I t ti


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Big-Bang Integration

In theory:

- if we have already tested components why not justif we have already tested components why not just

combine them all at once? Wouldnt this save time?combine them all at once? Wouldnt this save time?

- (based on false assumption of no faults)(based on false assumption of no faults) In practice:

- takes longer to locate and fix faultstakes longer to locate and fix faults

- re-testing after fixes more extensivere-testing after fixes more extensive

- end result? takes more timeend result? takes more time

I t l I t ti


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Incremental Integration

Baseline 0: tested component

Baseline 1: two components

Baseline 2: three components, etc.

Advantages:- easier fault location and fixeasier fault location and fix

- easier recovery from disaster / problemseasier recovery from disaster / problems

-interfaces should have been tested in componentinterfaces should have been tested in component

tests, but ..tests, but ..

- add to tested baselineadd to tested baseline

T D I t ti


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Baselines:- baseline 0: component abaseline 0: component a- baseline 1: a + bbaseline 1: a + b- baseline 2: a + b + cbaseline 2: a + b + c

- baseline 3: a + b + c + dbaseline 3: a + b + c + d- etc.etc.

Need to call to lower

level components not

yet integrated

Stubs: simulate missing

components

Top-Down Integration

a

b c

d e f g

h i j k l m

n o

a

b c

d e f g

h i j

St b


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Stubs

Stub (Baan: dummy sessions) replaces a called

component for integration testing

Keep it Simple

- print/display name (I have been called)print/display name (I have been called)- reply to calling module (single value)reply to calling module (single value)

- computed reply (variety of values)computed reply (variety of values)

- prompt for reply from testerprompt for reply from tester

- search list of repliessearch list of replies

- provide timing delayprovide timing delay

P & f t d h


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Pros & cons of top-down approach

Advantages:

- critical control structure tested first and most oftencritical control structure tested first and most often

- can demonstrate system early (show workingcan demonstrate system early (show working

menus)menus) Disadvantages:

- needs stubsneeds stubs

- detail left until lastdetail left until last

- may be difficult to "see" detailed output (but shouldmay be difficult to "see" detailed output (but should

have been tested in component test)have been tested in component test)

- may look more finished than it ismay look more finished than it is

Bottom up Integration


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a

b c

e f g

k l m

d

i

n o

h j

Baselines:- baseline 0: component nbaseline 0: component n- baseline 1: n + ibaseline 1: n + i- baseline 2: n + i + obaseline 2: n + i + o

- baseline 3: n + i + o + dbaseline 3: n + i + o + d- etc.etc.

Needs drivers to call

the baseline configuration

Also needs stubs

for some baselines

Bottom-up Integration

b

d

i

n o

h j

Drivers


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Drivers

Driver(Baan: dummy sessions): test harness:

scaffolding

specially written or general purpose

(commercial tools)

- invoke baselineinvoke baseline

- send any data baseline expectssend any data baseline expects

- receive any data baseline produces (print)receive any data baseline produces (print)

each baseline has different requirements fromthe test driving software

Pros & cons of bottom up approach


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Pros & cons of bottom-up approach

Advantages:- lowest levels tested first and most thoroughly (butlowest levels tested first and most thoroughly (but

should have been tested in unit testing)should have been tested in unit testing)

- good for testing interfaces to external environmentgood for testing interfaces to external environment

(hardware, network)(hardware, network)- visibility of detailvisibility of detail

Disadvantages

-no working system until last baselineno working system until last baseline

- needs both drivers and stubsneeds both drivers and stubs

- major control problems found lastmajor control problems found last

Minimum Capability Integration


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Baselines:- baseline 0: component abaseline 0: component a- baseline 1: a + bbaseline 1: a + b- baseline 2: a + b + dbaseline 2: a + b + d

- baseline 3: a + b + d + ibaseline 3: a + b + d + i- etc.etc.

Needs stubs

Shouldn't need drivers(if top-down)

Minimum Capability Integration

(also called Functional)

f g

k l m

a

b

d

i

c

e

n o

h j

a

b

d

i

c

e

n o

h j

Pros & cons of Minimum Capability


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Pros & cons of Minimum Capability

Advantages:

- control level tested first and most oftencontrol level tested first and most often

- visibility of detailvisibility of detail

- real working partial system earliestreal working partial system earliest Disadvantages

- needs stubsneeds stubs

Thread Integration


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k l mih j

b c

a

f gd e

n o

(also called functional)

order of processing some eventdetermines integration order

interrupt, user transaction

minimum capability in time

advantages:

- critical processing firstcritical processing first

- early warning ofearly warning of

performance problemsperformance problems

disadvantages:

- may need complex drivers and stubsmay need complex drivers and stubs

b c

k l mih j

f gd e

Integration Guidelines


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Integration Guidelines

minimise support software needed

integrate each component only once

each baseline should produce an easily

verifiable result integrate small numbers of components at

once

- one at a time for critical or fault-prone componentsone at a time for critical or fault-prone components

- combine simple related componentscombine simple related components


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Lifecycle

1 2 3 ISTQB / ISEB Foundation Exam Practice


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Contents



Component Testing




Acceptance testing

Maintenance testing

1 2 3

4 5 6


System testing


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System testing

last integration step functional

- functional requirements and requirements-basedfunctional requirements and requirements-based

testingtesting

- business process-based testingbusiness process-based testing

non-functional

- as important as functional requirementsas important as functional requirements

- often poorly specifiedoften poorly specified- must be testedmust be tested

often done by independent test group

Functional system testing


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Functional system testing

Functional requirements

- a requirement that specifies a function that a systema requirement that specifies a function that a system

or system component must perform (ANSI/IEEEor system component must perform (ANSI/IEEE

Std 729-1983, Software Engineering Terminology)Std 729-1983, Software Engineering Terminology)

Functional specification

- the document that describes in detail thethe document that describes in detail the

characteristics of the product with regard to itscharacteristics of the product with regard to its

intended capability (BS 4778 Part 2, BS 7925-1)intended capability (BS 4778 Part 2, BS 7925-1)

Requirements-based testing


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Requirements based testing

Uses specification of requirements as thebasis for identifying tests

- table of contents of the requirements spec providestable of contents of the requirements spec provides

an initial test inventory of test conditionsan initial test inventory of test conditions

- for each section / paragraph / topic / functional area,for each section / paragraph / topic / functional area,

risk analysis to identify most important / criticalrisk analysis to identify most important / critical

decide how deeply to test each functional areadecide how deeply to test each functional area

Business process-based testing


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Business process based testing

Expected user profiles- what will be used most often?what will be used most often?

- what is critical to the business?what is critical to the business?

Business scenarios

- typical business transactions (birth to death)typical business transactions (birth to death)

Use cases

- prepared cases based on real situationsprepared cases based on real situations

Non-functional system testing


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Non functional system testing

different types of non-functional system tests:

- usabilityusability - configuration / installation- configuration / installation

- securitysecurity - reliability / qualities- reliability / qualities

- documentationdocumentation - back-up / recovery- back-up / recovery- storagestorage - performance, load, stress- performance, load, stress

- volumevolume

Performance Tests


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Timing Tests

- response and service timesresponse and service times

- database back-up timesdatabase back-up times

Capacity & Volume Tests

- maximum amount or processing ratemaximum amount or processing rate

- number of records on the systemnumber of records on the system

- graceful degradationgraceful degradation

Endurance Tests (24-hr operation?)- robustness of the systemrobustness of the system

- memory allocationmemory allocation

Multi-User Tests


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Concurrency Tests

- small numbers, large benefitssmall numbers, large benefits

- detect record locking problemsdetect record locking problems

Load Tests

- the measurement of system behaviour underthe measurement of system behaviour under

realistic multi-user loadrealistic multi-user load

Stress Tests

- go beyond limits for the system - know what willgo beyond limits for the system - know what willhappenhappen

- particular relevance for e-commerceparticular relevance for e-commerceSource: Sue Atkins, Magic Performance Managemen

Usability Tests


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Who should design / perform these tests?

y

messages tailored and meaningful to (real)users?

coherent and consistent interface?

sufficient redundancy of critical information? within the "human envelope"? (72 choices)

feedback (wait messages)?

clear mappings (how to escape)?

Security Tests


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y

passwords encryption

hardware permission devices

levels of access to information authorisation

covert channels

physical security

Configuration and Installation


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g

Configuration Tests

- different hardware or software environmentdifferent hardware or software environment

- configuration of the system itselfconfiguration of the system itself

- upgrade paths - may conflictupgrade paths - may conflict Installation Tests

- distribution (CD, network, etc.) and timingsdistribution (CD, network, etc.) and timings

- physical aspects: electromagnetic fields, heat,physical aspects: electromagnetic fields, heat,

humidity, motion, chemicals, power supplieshumidity, motion, chemicals, power supplies

- uninstall (removing installation)uninstall (removing installation)

Reliability / Qualities


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y

Reliability

- "system will be reliable" - how to test this?"system will be reliable" - how to test this?

- "2 failures per year over ten years""2 failures per year over ten years"

- Mean Time Between Failures (MTBF)Mean Time Between Failures (MTBF)- reliability growth modelsreliability growth models

Other Qualities

- maintainability, portability, adaptability, etc.maintainability, portability, adaptability, etc.

Back-up and Recovery


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Back-ups

- computer functionscomputer functions

- manual procedures (where are tapes stored)manual procedures (where are tapes stored)

Recovery- real test of back-upreal test of back-up

- manual procedures unfamiliarmanual procedures unfamiliar

- should be regularly rehearsedshould be regularly rehearsed

- documentation should be detailed, clear anddocumentation should be detailed, clear and

thoroughthorough

Documentation Testing


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Documentation review

- check for accuracy against other documentscheck for accuracy against other documents

- gain consensus about contentgain consensus about content

- documentation exists, in right formatdocumentation exists, in right format Documentation tests

- is it usable? does it work?is it usable? does it work?

- user manualuser manual

- maintenance documentationmaintenance documentation

Lifecycle



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ContentsModels for testing, economics of testing


Component Testing




Acceptance testing

Maintenance testing

4 5 6



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Tests the completed system working inconjunction with other systems, e.g.

- LAN / WAN, communications middlewareLAN / WAN, communications middleware

- other internal systems (billing, stock, personnel,other internal systems (billing, stock, personnel,

overnight batch, branch offices, other countries)overnight batch, branch offices, other countries)

- external systems (stock exchange, news, suppliers)external systems (stock exchange, news, suppliers)

- intranet, internet / wwwintranet, internet / www

- 3rd party packages3rd party packages- electronic data interchange (EDI)electronic data interchange (EDI)

Approach


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Identify risks- which areas missing or malfunctioning would bewhich areas missing or malfunctioning would be

most critical - test them firstmost critical - test them first

Divide and conquer

- test the outside first (at the interface to your system,test the outside first (at the interface to your system,

e.g. test a package on its own)e.g. test a package on its own)

- test the connections one at a time firsttest the connections one at a time first

(your system and one other)(your system and one other)- combine incrementally - safer than big bangcombine incrementally - safer than big bang

(non-incremental)(non-incremental)


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Lifecycle



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Component Testing




Acceptance testing

Maintenance testing

4 5 6

User acceptance testing


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Final stage of validation- customer (user) should perform or be closelycustomer (user) should perform or be closely

involvedinvolved

- customer can perform any test they wish, usuallycustomer can perform any test they wish, usually

based on their business processesbased on their business processes

- final user sign-offfinal user sign-off

Approach

- mixture of scripted and unscripted testingmixture of scripted and unscripted testing- Model Office concept sometimes usedModel Office concept sometimes used

Why customer / user involvement


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Users know:- what really happens in business situationswhat really happens in business situations

- complexity of business relationshipscomplexity of business relationships

- how users would do their work using the systemhow users would do their work using the system- variants to standard tasks (e.g. country-specific)variants to standard tasks (e.g. country-specific)

- examples of real casesexamples of real cases

- how to identify sensible work-aroundshow to identify sensible work-arounds

Benefit: detailed understanding of the new systemBenefit: detailed understanding of the new system

User Acceptance testing


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20% of functionby 80% of code

80% of function

by 20% of code

System testing

distributed overthis line

Acceptance testing

distributed overthis line

Contract acceptance testing


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Contract to supply a software system- agreed at contract definition stageagreed at contract definition stage

- acceptance criteria defined and agreedacceptance criteria defined and agreed

- may not have kept up to date with changesmay not have kept up to date with changes Contract acceptance testing is against the

contract and any documented agreed changes

- not what the users wish they had asked for!not what the users wish they had asked for!

- this system, not wish systemthis system, not wish system

Alpha and Beta tests: similarities


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Testing by [potential] customers orrepresentatives of your market

- not suitable for bespoke softwarenot suitable for bespoke software

When software is stable

Use the product in a realistic way in its

operational environment

Give comments back on the product

- faults foundfaults found- how the product meets their expectationshow the product meets their expectations

- improvement / enhancement suggestions?improvement / enhancement suggestions?

Alpha and Beta tests: differences


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Alpha testing- simulated or actual operational testing at an in-simulated or actual operational testing at an in-

house site not otherwise involved with the softwarehouse site not otherwise involved with the software

developers (i.e. developers site)developers (i.e. developers site)

Beta testing

operational testing at a site not otherwise involved

with the software developers (i.e. testers site,

their own location)

Acceptance testing motto


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If you don't have patience to test the system

the system will surely test your patience

If you don't have patience to test the system

the system will surely test your patience

Lifecycle

1 2 3

4 5 6



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Component TestingIntegration testing in the small



Acceptance testing

Maintenance testing

4 5 6

Maintenance testing


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Testing to preserve quality:- different sequencedifferent sequence

development testing executed bottom-updevelopment testing executed bottom-up

maintenance testing executed top-downmaintenance testing executed top-down

different test data (live profile)different test data (live profile)

- breadth tests to establish overall confidencebreadth tests to establish overall confidence

- depth tests to investigate changes and critical areasdepth tests to investigate changes and critical areas

- predominantly regression testingpredominantly regression testing

What to test in maintenance testing


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Test any new or changed code Impact analysis

- what could this change have an impact on?what could this change have an impact on?

-how important is a fault in the impacted area?how important is a fault in the impacted area?

- test what has been affected, but how much?test what has been affected, but how much?

most important affected areas?most important affected areas?

areas most likely to be affected?areas most likely to be affected?

whole system?whole system? The answer: It depends

Poor or missing specifications


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Consider what the system should do- talk with userstalk with users

Document your assumptions

-ensure other people have the opportunity to reviewensure other people have the opportunity to reviewthemthem

Improve the current situation

- document what you do know and find outdocument what you do know and find out

Track cost of working with poor specifications- to make business case for better specificationsto make business case for better specifications

What should the system do?


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Alternatives- the way the system works now must be right (exceptthe way the system works now must be right (except

for the specific change) - use existing system as thefor the specific change) - use existing system as the

baseline for regression testsbaseline for regression tests

- look in user manuals or guides (if they exist)look in user manuals or guides (if they exist)

- ask the experts - the current usersask the experts - the current users

Without a specification, you cannot really test,

only explore. You can validate, but not verify.

Lifecycle

1 2 3

4 5 6



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Summary: Key PointsV-model shows test levels, early test design


Component testing using the standardIntegration testing in the small: strategies



Acceptance testing: user responsibility

Maintenance testing to preserve quality

4 5 6

istqb chapter2

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