Principles of Information Systems, Sixth Edition Systems Design, Implementation, Maintenance, and...

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Principles of Information Systems, Sixth Edition

Systems Design, Implementation, Maintenance, and Review

Chapter 13

Systems Design

Top Uses for New Systems in Various Industries

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

Physical Design

• Hardware design• Software design• Database design• Telecommunications design• Personnel design• Procedures and controls design

Special System Design Considerations

• Procedures for signing on• Interactive processing • Interactive dialog• Preventing, detecting, and correcting errors

The Scope of Design

Procedures for Signing On

Interactive Processing

Emergency Alternate Procedures & Disaster Recovery

• Telecommunications backup• Personnel backup• Hardware backup• Software and database backup

Hardware Backup

• Disaster recovery plans• Hot site• Cold site

Software & Database Backup

• Selective backups• Incremental backups• Image log

Preventing, Detecting, and Correcting Errors

Object-Oriented Design

Systems Controls

• Deterrence controls• Input controls• Processing controls• Output controls• Database controls• Telecommunications controls• Personnel controls

Request for Proposal

Financial Options

Cost/Benefit Analysis

Evaluation Techniques

• Group consensus• Benchmark tests• Cost/benefit analysis• Point evaluation

The Final Evaluation

Point Evaluation

Freezing Design Specifications

The Design Report

Systems Implementation

Acquiring Software: Make or Buy Software?

• Externally developed software– Lower cost – Lower risk– Ease of installation

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

In-House Developed Software

• Chief programmer teams • The programming life cycle

Chief Programmer Teams

The Programming Life Cycle

Tools & Techniques for Software Development

• Cross-platform development• Integrated development environments • CASE tools• Structured design• Structured programming• Structured walkthroughs

Characteristics of Structured Programming

Structured Design and Programming

Structured Walkthroughs

Additional Implementation Activities

• Acquiring database and telecommunication systems

• User preparation• Hiring and training IS personnel• Site preparation• Data preparation

Additional Implementation Activities

• Installation• Testing

– Unit testing– System testing– Volume testing– Integration testing– Acceptance testing

Testing

Start-Up Approaches

Systems Maintenance

Reasons for Maintenance

• 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

Types of Maintenance

• Slipstream upgrade• Patch• Release• Version

The Financial Implications of Maintenance

The Relationship Between Maintenance and Design

Systems Review

Types of Review Procedures

Factors to Consider During Systems Review

• Mission• Goals• Hardware/software• Database• Telecommunications• IS personnel• Control

• Training• Costs• Complexity• Reliability• Efficiency• Response time• Documentation

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

Principles of Information Systems, Sixth Edition Systems Design, Implementation, Maintenance, and...

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