Why Is Testing Stage of Sdlc so Important?

Only available on StudyMode
  • Download(s) : 322
  • Published : December 1, 2012
Open Document
Text Preview
Why is the testing stage of systems
development so important?
November 2012

Introduction
• Systems Development Lifecycle
• Types of SDLC
• Stages of SDLC












Waterfall method
Testing
Programme Testing
Acceptance Testing
Limitations of Testing
Case Study 1: University of Salford
Case Study 2: Knight Capital Group
Summary
Conclusion
References

Systems Development Lifecycle
• Systems Development Life Cycle (SDLC) is the
process of developing information systems
through various stages from identifying initial
requirements through analysis, design, testing,
implementation and maintenance.
• Many different models but each generally
consists of a series of defined steps or stages.

Laudon & Laudon (2006)

Types of SDLC
• Waterfall
• Fountain
• Spiral
• Rapid prototyping
• Incremental

Bocij et al (2006)

Waterfall
• One of the oldest, best known

• Linear sequential set of phases

• Review at end of each phase before
moving on to the next
• Logical chain of events, e.g.
programming cannot begin until
specification completed

• Many different versions
• Many critics – does not work?

Laplante & Neill (2004) Dennis et al (2008)

Stages of SDLC
Vary according to the methodology used but usually
some variation of the waterfall method which has
Galin (2004)
served as a framework for others.


Systems analysis - identify problems & establish requirements



Systems Design – create design specifications



Programming - translate design specification into code



Testing



Conversion – plan conversion,
train users



Production & Maintenance –
operate, evaluate and

modify the system
Laudon & Laudon (2006)

Testing
Why test? System should be tested to ensure that it meets the requirements laid out at the start of the process.

• Develop a test plan
• Involve users as well as developers
• Simulate data and test system processes e.g.
entering a new record, inserting incorrect data

Laudon & Laudon (2006)

Test Plan
Test
Number

Purpose of Test

Test Data

Expected Result

Actual Result

1

Test the validation
rule on the "Date of
Birth" field to ensure
that valid dates of
birth can be entered.

15/02/1988

Accepted

Accepted

2

Test the validation
rule on the Date of
Birth field to ensure
that a date in the
future cannot be
entered.

14/10/2013

Rejected

Accepted

Adapted from: Laudon & Laudon (2006)

Testing
2 basic phases of testing:

• programme testing – ensures that the programmes work as expected in controlled environment

• acceptance testing – ensures users are able
to use the system and that it operates
as expected when in use.

Laudon & Laudon (2006)

Programme Testing
3 phases
• unit testing - individual modules of the system are
tested for any potential errors in the code.
• integration testing - to check the modules work
together as expected
• complete system testing - see how all the components
will work under various conditions

Bocij et al (2006)

Acceptance Testing
User Acceptance Testing (UAT) by actual end users of the
system to determine how well it meets their expectations
and requirements.

• alpha testing – using simulated data
• beta testing – using actual data –
final stage before implementation

Bocij et al (2006)

Acceptance Testing
• Security testing – whether security policies have been implemented as intended
• Recovery testing – how the system reacts when it has

been forced to fail
• Performance testing - in different environments
• Stress testing - attempts to “break” the system by not

following guidelines. Looks at how the system
performs under heavy demand.
Bocij et al (2006)

Limitations of Testing
• Impossible to guarantee that once a system is tested it

will work exactly as expected
• Too many factors to carry out exhaustive testing
• It is often given...
tracking img