Expert answer:discuss the role of system maintenance

Expert answer:First, discuss the role of system maintenance in terms of types of maintenance and particularly, the cost of maintenance vs. new development. (10 pts) Secondly, discuss the process of controlling maintenance requests in general (see fig. 14-8) (10 pts) Lastly, provide your own interpretive discussion of how the “traditional” SDLC view point of controlling maintenance requests would need to change to fit into the Agile System Development Methodology. Essentially, how would you manage and control change requests in an Agile environment. (10 pts) For full credit, ensure that you list any/all steps, define all terms, and demonstrate full understanding of any concept you discuss. For example, if discussing “Agile”, tell enough about it to convince me you know what it means. 1 page, 4 paragraphs.
hoffer_msad6e_ch14.ppt

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Modern Systems Analysis
and Design
Seventh Edition
Jeffrey A. Hoffer
Joey F. George
Joseph S. Valacich
Chapter 14
Maintaining Information
Systems
Learning Objectives
✓
✓
✓
✓
Explain and contrast four types of system maintenance.
Describe several factors that influence the cost of
maintaining an information system and apply these
factors to the design of maintainable systems.
Describe maintenance management issues, including
alternative organizational structures, quality
measurement, processes for handling change requests,
and configuration management.
Explain the role of CASE tools in maintaining information
systems.
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
2
Maintaining Information
Systems
FIGURE 14-1
Systems development life cycle
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
3
The Process of Maintaining
Information Systems
Process of returning to the beginning of
the SDLC and repeating development
steps focusing on system change until
the change is implemented
 Maintenance is the longest phase in the
SDLC.

Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
4
The Process of Maintaining
Information Systems (Cont.)
 Four
major activities:
Obtaining
maintenance requests
Transforming requests into changes
Designing changes
Implementing changes
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
5
FIGURE 14-2
System Service Request
for purchasing
fulfillment system (Pine
Valley Furniture)
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Deliverables and Outcome
 The
maintenance phase of the
SDLC is basically a subset of the
activities of the entire
development process.
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Deliverables and Outcome
(Cont.)
 The
deliverables and outcomes
from the process are the
development of a new version of
the software and new versions of
all design documents created or
modified during the maintenance
effort.
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
8
Deliverables and Outcome
(Cont.)
FIGURE 14-3
Maintenance activities parallel those of
the SDLC
Chapter 14
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Types of System Maintenance

Chapter 14
Maintenance: changes made to
a system to fix or enhance its
functionality
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
10
Types of System Maintenance
(Cont.)

Chapter 14
Corrective maintenance:
changes made to a system to
repair flaws in its design, coding,
or implementation
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
11
Types of System Maintenance
(Cont.)

Adaptive maintenance:
changes made to a system to
evolve its functionality to
changing business needs or
technologies
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
12
Types of System Maintenance
(Cont.)

Perfective maintenance:
changes made to a system to
add new features or to improve
performance
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
13
Types of System Maintenance
(Cont.)

Chapter 14
Preventive maintenance:
changes made to a system to
avoid possible future problems
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
14
Types of System Maintenance
(Cont.)
Figure 14-4
Value and non-value adding of different types of maintenance
(Sources: Based on Andrews and Leventhal,1993; Pressman,
2005.)
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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The Cost of Maintenance


Chapter 14
Many organizations allocate 60-80%
of information systems budget to
maintenance.
Maintainability: the ease with which
software can be understood,
corrected, adapted, and enhanced
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
16
The Cost of Maintenance (Cont.)
FIGURE 14-5
New development
versus
maintenance as
a percentage of
the software
budget over the
years
(Source: Based
on Pressman,
2005.)
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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The Cost of Maintenance (Cont.)

Factors that influence system
maintainability:






Chapter 14
Latent defects
Number of customers for a given
system
Quality of system documentation
Maintenance personnel
Tools
Well-structured programs
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
18
The Cost of Maintenance (Cont.)
FIGURE 14-6
Quality documentation
eases Maintenance
(Source: Based on
Hanna, M. 1992.
“Using Documentation
as a Life-Cycle Tool.”
Software Magazine
[December]: 41–46.)
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Managing Maintenance Personnel
Number of people working in
maintenance has surpassed number
working in development.
 Maintenance work is often viewed
negatively by IS personnel.

Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Managing Maintenance Personnel
(Cont.)
Organizations often rotate personnel in
and out of maintenance roles in order to
lessen negative feelings about
maintenance.
 Organizations have historically rewarded
people involved in new development
better than maintenance personnel.

Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Managing Maintenance Personnel
(Cont.)

Three possible organizational structures:
— maintenance group consists of
different personnel than development group
 Separate
 Combined
— developers also maintain
systems
— maintenance personnel work
within the functional business unit
 Functional
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Managing Maintenance Personnel
(Cont.)
Maintenance
Organization
Type
Separate
Advantages
Disadvantages
Improved system
and documentation
quality
Ignorance of critical
undocumented
information
Combined
Maintenance group
knows all about
system
Less emphasis on
good documentation
Functional
Personnel have
vested interest
Limited job mobility
and human or
technical resources
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Measuring Maintenance
Effectiveness
 Must
measure the following
factors:
Number
of failures
Time between each failure
Type of failure
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Measuring Maintenance
Effectiveness (Cont.)
 Mean
time between failures
(MTBF): a measurement of error
occurrences that can be tracked
over time to indicate the quality of a
system
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Measuring Maintenance
Effectiveness (Cont.)
FIGURE 14-7
How the mean time
between failures
should change over time
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
26
Controlling Maintenance
Requests
Maintenance requests can be frequent.
 Prioritize based on type and urgency of
request.
 Evaluations are based on feasibility
analysis.

Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Controlling Maintenance
Requests (Cont.)
FIGURE 14-8
How to prioritize
maintenance
requests
Chapter 14
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Controlling Maintenance
Requests (Cont.)
FIGURE 14-9
How a maintenance request moves
through an organization
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
29
Configuration Management

Chapter 14
Configuration management:
the process of ensuring that only
authorized changes are made to
the system
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Configuration Management
(Cont.)

Chapter 14
Baseline modules: software
modules that have been tested,
documented, and approved to
be included in the most recently
created version of a system
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
31
Configuration Management
(Cont.)


Chapter 14
System librarian: a person
responsible for controlling the checking
out and checking in of baseline
modules when a system is being
developed or maintained
Build routines: guidelines that list the
instructions to construct an executable
system from the baseline source code
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Role of CASE and Automated
Development Tools in Maintenance

Traditional systems development
 Emphasis
is on coding and testing.
 Changes are implemented by coding and
testing first.
 Documentation is done after maintenance is
performed.
 Keeping documentation current is often
neglected due to time-consuming nature of
task.
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
33
Role of CASE and Automated
Development Tools in Maintenance
(Cont.)

Development with CASE
 Emphasis
is on design documents.
 Changes are implemented in design
documents.
 Code is regenerated using code generators.
 Documentation is updated during
maintenance.
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
34
Role of CASE and Automated
Development Tools in Maintenance
(Cont.)

Reverse engineering: automated tools
that read program source code as input
and create graphical and textual
representations of design-level information
such as program control structures, data
structures, logical flow, and data flow
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
35
Role of CASE and Automated
Development Tools in Maintenance
(Cont.)

Reengineering: automated tools that read
program source code as input; perform an
analysis of the program’s data and logic;
and then automatically, or interactively
with a systems analyst, alter an existing
system in an effort to improve its quality or
performance
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
36
Role of CASE and Automated
Development Tools in Maintenance
(Cont.)
Figure 14-10 Visual Studio .NET engineer applications into Visio UML
diagrams (Source: Microsoft Corporation.)
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
37
Web Site Maintenance
 Special
24
considerations:
X 7 X 365
 Nature
of continuous availability makes
maintenance challenging.
 Pages under maintenance can be locked.
 Consider
using date and time stamps to
indicate when changes are made instead.
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
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Web Site Maintenance (Cont.)
Check
for broken links
HTML Validation
 Pages
should be processed by a code
validation routine before publication.
Reregistration
 When
content significantly changes, site
may need to be reregistered with search
engines.
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
39
Web Site Maintenance (Cont.)
Future
Editions
 Consistency
is important to users.
 Post indications of future changes to
the site.
 Batch changes.
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
40
Electronic Commerce Application:
Maintaining an Information System for
Pine Valley Furniture’s WebStore

To maintain PVF’s WebStore, the following
questions need to be addressed:
 “How
much is our Web site worth?”
 “How much does it cost our company when our
Web site goes down?”
 “How reliable does our Web site need to be?”
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
41
Electronic Commerce Application:
Maintaining an Information System for
Pine Valley Furniture’s WebStore
(Cont.)

Pine Valley Furniture needs to immediately
develop a plan for addressing the WebStore’s
service level problems.
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
42
Summary

In this chapter you learned how to:
✓
Explain and contrast four types of system maintenance.
Describe several facts that influence the cost of
maintaining an information system and apply these
factors to the design of maintainable systems.
Describe maintenance management issues, including
alternative organizational structures, quality
measurement, processes for handling change requests,
and configuration management.
Explain the role of CASE tools in maintaining
information systems.
✓
✓
✓
Chapter 14
© 2014 Pearson Education, Inc. Publishing as Prentice Hall
43
Copyright © 2014 Pearson Education, Inc.
Publishing as Prentice Hall
…
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