Software Development Model
0 The development process adopted will depend on the
project aims and goal
0 There are numerous model have been developed to
achieve different required objectives
0 The life cycle model that is adopted for a project will
have a big impact on the testing that is carried out
0 Testing are highly related to software development
activities
0 Testing is organized to fit the development life cycle
Software Development Model
0 In every development life cycle, a part of testing is
focused on verification testing and validation testing
0 Verification testing is concerned with evaluating a
work product, component or system to determine
whether it meets the requirement set
0 Validation testing is concerned with evaluating a
work product, component or system to determine
whether it meets the user needs and requirements
Waterfall Model
Need,
wish,
policy, law
User Requirements
Systems
Requirements
Global Design
Detail Design
Implementation
Testing
Testing
at the
End
V-Model
0 Was developed to address some of the problems
experienced using the traditional waterfall:
0 Defects were being found too late
0 The V-model provides guidance that testing needs to
begin as early as possible
0 Testing – in parallel with development
V-Model
0 Common V-model uses four test levels
0 Component testing – search defects & verifies the
functioning of software components (module, programs,
objects, classes)
0 Integration testing –tests interface between
components, interface with OS, file systems and
hardware
0 System testing – concerned with the behavior of the
whole system
0 Acceptance testing – validation testing with respect to
user needs, requirements, business process
V-Model
Need,
wish,
policy, law
Operational
systems
Preparation
Acceptance Test
User
Requirements
Preparation
Systems Test
Systems
Requirements
Global Design
System Test
Execution
Preparation
Integration Test
Detail Design
Acceptance
Test Execution
Integration
Test Execution
Component
Test Execution
Implementation
Iterative Life Cycle
Implement
Test
Build
Develop
Define
Phase 3
Implement
Test
Build
Define
Implement
Test
Build
Develop
Define
Develop
Phase 2
Phase 1
Delivery is divided into increments or builds
Subsequence increments will need testing for new
functionality, regression testing of the existing functionality,
and integration testing of both new and existing parts
Iterative Life Cycle Example
0 Rapid Application Development (RAD) – parallel
development
Function 1
Define
Develop
Build
Test
Function 2
Define
Develop
Build
Test
Function 3
Define
Develop
Build
Test
Function 4
Define
Develop
Build
Test
Iterative Life Cycle Example:
Agile Development
0 Currently one of the most well-known development life-
cycle model & human friendly
0 Characteristic:
0 Promotes the generation of business stories to define
0
0
0
0
functionality
Promotes pair programming and shared code ownership
State component test scripts shall be written before the code
is written
States that integration and testing of code shall happen
several times
States that we always implement the simplest solution to
meet today’s problem
Testing within a Life Cycle
Model
0 Which ever life cycle model is being used, there are
several characteristic of good testing:
0 Every development activity, there is a corresponding
testing activity
0 Each test level has test objectives specific to that level
0 The analysis and design of tests for a given test level
should begin during the corresponding development
activity
0 Tester should be involved in reviewing documents as
soon as drafts are available in the development cycle
Test Levels:
Component Testing
0 Also known as unit, module and program testing
0 Searches for defects and verifies the functioning of software
0 May be done in isolation from the rest of systems
0 Most often stubs and drivers are used to replace missing
software
0 May include testing of functionality and specific nonfunctionality characteristic
0 Test cases are derived from work products – software
design, data model
0 Occurs with access to the code being tested
Test Levels:
Component Testing
Component
A
A
Driver
Component
B
Stub
B
Test Levels:
Integration Testing
0 Test interfaces between components, interaction
between different parts of systems
0 There are may be more than one level of integration
testing
0 Greater the scope of integration – the more difficult to
isolate failures
0 Approaches:
0 Big-bang
0 Incremental-testing
Test Levels:
Systems Testing
0 Concerned with the behavior of the whole
system/product as defined by the scope of development
project or product
0 Tests based on risks or requirement specification,
business processes, use cases or high level descriptions of
systems behavior
0 Should investigate both functional and non-functional
requirements
0 Requires controlled test environment