Chapter 14:
OOSAD Implementation and
Operation
Object-Oriented Systems Analysis and
Design
Joey F. George, Dinesh Batra,
Joseph S. Valacich, Jeffrey A. Hoffer
© Prentice Hall, 2004
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Chapter Objectives
– Describe the process of coding, testing, and converting
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an organizational information system.
Apply four installation strategies: direct, parallel, singlelocation, and phased.
List the deliverables for documenting the system and
providing user training and support.
Compare various training modes.
Discuss the issues of providing support to end users.
Explain why systems implementation sometimes fails.
Explain and contrast four types of maintenance.
Describe factors that influence system maintenance
costs.
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What Is Coding?

Translation of physical design specifications into
working computer code

Coding involves use of programming languages
such as Java or Visual Basic

eXtreme programming – an intensive coding and
testing approach involving two-person teams and
customer involvement
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Reuse

The use of previously written software resources,
especially objects and components, in new
applications

Results in great savings of system development
time

Object-oriented systems are very conducive to
reuse.
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Approaches to Reuse
Cost and commitment
low

Ad hoc – individual, unplanned use
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Facilitated – use informally managed and
disseminated by expert guru evangelists

Managed – organizationally enforced reuse
policies and practices
Designed – reusable components developed and
high maintained in-house
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What Is Software Application
Testing?

Manual and automated procedures for validating
correctness of program code, including syntactical
and execution issues

Testing Syntax – grammatical rules applied to
programming languages

Testing Execution – logic and performance of the
software during operation
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Tests can be manual or automated, and may or
may not involve code execution.
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Tests Without Program Execution

Inspections (manual)
– Participants examine program code for
predictable, language-specific errors

Syntax checking (automated)
– Compiler or interpreter tests source code for
grammatical errors while translating to
executable format
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Manual Tests With Program
Execution

Desk checking
– trace through the logic of the code, identifying
possible logical errors
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Walkthroughs
– Like desk-checking, but in a group-oriented,
more structured process
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Code walkthrough is one of many types of structured
walkthroughs.
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Automated Tests With Program
Execution

Unit tests – a module tested in isolation for internal
consistency

Integration tests – testing all modules and
components of the application together for interaction
compatibilities

System tests – testing all programs and applications
together to ensure performance and reliability

Acceptance tests – user-satisfaction tests
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A test case is a
specific scenario of
transactions,
queries, or
navigation paths
that represent a
typical, abnormal,
or critical use of the
system.
Allows repeated
testing with each
application change
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What Is Installation?

The organizational process of turning over from
the old information system to the new one

Types:
– Direct
– Parallel
– Single location
– Phased
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Direct – Cold turkey, low cost, greater impact of errors
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Parallel – old and new coexist, minimize error
impact, high cost in system resources
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Single Location – Pilot approach, allows learning and
minimizes error impact, lower resource demand than parallel,
difficult to coordinate and maintain
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Phased – Staged and incremental, supports phased
system development, minimize error impact, difficult
to coordinate old components and new components
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Types of Documentation

System – detailed information about a
system’s design specifications, its inner
workings, and its functionality

User – written or other visual information
about an application system, how it works,
and how to use it.
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Types of System Documentation

Internal – comments in source code,
generated during the coding process or
automatically by software compilers or
documenters
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External – outcomes of all structured
diagrams, including use cases, design
classes, activity and sequence diagrams, etc.
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User documentation is
often in the form of
online help,
sometimes with Web
connections for further
information.
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What Is Training and Support?

Providing on-going educational and
problem-solving assistance to information
systems users
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Training and support material and jobs must
be designed along with the associated
information systems
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Training methods can be interpersonal, manual, or
automated.
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Electronic Performance
Support Systems (EPSS),
like Microsoft Office
Assistant, are components
of software applications
that embed training and
information for the user, in
the form of tutorials, expert
systems, and hyperlink
jumps to reference topics.
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Help Desks and Information
Centers

Help desk – a single point of contact for all
user inquiries and problems about a
particular information system or for all
users in a particular department
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Information center – an organizational unit
whose mission is to support users in
exploiting information technology
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What Is System Maintenance?

Changes made to a system to fix or enhance its
functionality
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System maintenance operates as repeated,
miniaturized systems development cycles.
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Maintenance Cost Factors
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Latent defects
Number of customers for the system
Quality of system documentation
Quality of maintenance personnel
Availability of automated tools
Quality of program code and system design
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Recap
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After studying this chapter we learned to:
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Describe coding, testing, and converting.
Apply four installation strategies.
Generate system and user documentation.
Compare training modes.
Discuss techniques of user support.
Discuss maintenance types.
Discuss maintenance cost factors.
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