Systems Design, Implementation,
Maintenance, and Review
Chapter 13
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Principles and Learning Objectives
• Designing new systems or modifying existing ones
should always be aimed at helping an organization
achieve its goals.
– State the purpose of systems design and discuss the
differences between logical and physical systems design.
– Outline key steps taken during the design phase.
– Describe some considerations and diagrams used during
object-oriented design.
– Define the term RFP and discuss how this document is used
to drive the acquisition of hardware and software.
– Describe the techniques used to make systems selection
evaluations.
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Principles and Learning Objectives
• The primary emphasis of systems implementation is to
make sure that the right information is delivered to the
right person in the right format at the right time.
– State the purpose of systems implementation and discuss the
various activities associated with this phase of systems
development.
– List the advantages and disadvantages of purchasing versus
developing software.
– Discuss the software development process and some of the
tools used in this process, including object-oriented program
development tools.
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Principles and Learning Objectives
• Maintenance and review add to the useful life of a
system but can consume large amounts of resources.
These activities can benefit from the same rigorous
methods and project management techniques applied to
systems development.
– State the importance of systems and software
maintenance and discuss the activities involved.
– Describe the systems review process.
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Systems Design
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Top Uses for New Systems in
Various Industries
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Logical Design
• Output design: types, format, content, frequency
• Input design: types, format, content, frequency
• Process design: calculations, comparisons,
manipulations
• File & database design: capabilities and organization
• Telecommunications design: high-level network
description
• Procedures design: automated & manual
• Controls & security design
• Personnel & job design
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Physical Design
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Hardware design
Software design
Database design
Telecommunications design
Personnel design
Procedures and controls design
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Special System Design
Considerations
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Procedures for signing on
Interactive processing
Interactive dialog
Preventing, detecting, and correcting errors
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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The Scope of Design
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Procedures for Signing On
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Interactive Processing
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Emergency Alternate Procedures &
Disaster Recovery
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Telecommunications backup
Personnel backup
Hardware backup
Software and database backup
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Hardware Backup
• Disaster recovery plans
• Hot site
• Cold site
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Software & Database Backup
• Selective backups
• Incremental backups
• Image log
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Preventing, Detecting, and Correcting
Errors
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Object-Oriented Design
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Systems Controls
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Deterrence controls
Input controls
Processing controls
Output controls
Database controls
Telecommunications controls
Personnel controls
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Request for Proposal
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Financial Options
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Cost/Benefit Analysis
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Cost/Benefit Analysis
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Evaluation Techniques
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Group consensus
Benchmark tests
Cost/benefit analysis
Point evaluation
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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The Final Evaluation
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Point Evaluation
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Freezing Design Specifications
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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The Design Report
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Systems Implementation
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Systems Implementation
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Acquiring Software: Make or Buy
Software?
• Externally developed software
– Lower cost
– Lower risk
– Ease of installation
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Make or Buy Software
• Steps
– Review needs, requirements, and costs
– Acquire software
– Modify or customize software
– Acquire software interfaces
– Test and accept the software
– Maintain the software
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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In-House Developed Software
• Chief programmer teams
• The programming life cycle
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Chief Programmer Teams
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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The Programming Life Cycle
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Tools & Techniques for Software
Development
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Cross-platform development
Integrated development environments
CASE tools
Structured design
Structured programming
Structured walkthroughs
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Characteristics of Structured
Programming
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Structured Design and Programming
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Structured Design and Programming
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Structured Walkthroughs
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Additional Implementation Activities
• Acquiring database and telecommunication
systems
• User preparation
• Hiring and training IS personnel
• Site preparation
• Data preparation
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Additional Implementation Activities
• Installation
• Testing
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Unit testing
System testing
Volume testing
Integration testing
Acceptance testing
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Testing
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Start-Up Approaches
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Start-Up Approaches
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Systems Maintenance
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Reasons for Maintenance
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Changes in business processes
Requests from stakeholders, users, or managers
Errors in the program
Technical and hardware problems
Corporate mergers & acquisitions
Government regulations
Changes in the operating system or hardware
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Types of Maintenance
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Slipstream upgrade
Patch
Release
Version
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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The Financial Implications of
Maintenance
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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The Relationship Between
Maintenance and Design
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Systems Review
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Types of Review Procedures
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Factors to Consider During Systems
Review
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Mission
Goals
Hardware/software
Database
Telecommunications
IS personnel
Control
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Training
Costs
Complexity
Reliability
Efficiency
Response time
Documentation
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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Summary
• Systems design - preparing detailed design needs for a new
system or modifying an existing system
• Systems implementation – installing the system and making
everything, including users, ready for its operation
• Software - can be purchased from vendors or developed in-house a decision termed the make-or-buy
• Systems maintenance - involves checking, changing, and
enhancing the system to make it more useful in obtaining user and
organizational goals
• Systems review - the process of analyzing systems to make sure
that they are operating as intended
MSIS 110: Introduction to Computers; Instructor: S. Mathiyalakan
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