principles of information systems - chapter 13

Principles of Information Systems, Sixth Edition

Systems Design, Implementation, Maintenance, and Review

Chapter 13

Principles of Information Systems, Sixth Edition

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.

Principles of Information Systems, Sixth Edition

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.

Principles of Information Systems, Sixth Edition

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.

Principles of Information Systems, Sixth Edition

Systems Design

Principles of Information Systems, Sixth Edition

Top Uses for New Systems in Various Industries

Principles of Information Systems, Sixth Edition

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

Principles of Information Systems, Sixth Edition

Physical Design

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

Principles of Information Systems, Sixth Edition

Special System Design Considerations

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

Principles of Information Systems, Sixth Edition

The Scope of Design

Principles of Information Systems, Sixth Edition

Procedures for Signing On

Principles of Information Systems, Sixth Edition

Interactive Processing

Principles of Information Systems, Sixth Edition

Emergency Alternate Procedures & Disaster Recovery

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

Principles of Information Systems, Sixth Edition

Hardware Backup

• Disaster recovery plans• Hot site• Cold site

Principles of Information Systems, Sixth Edition

Software & Database Backup

• Selective backups• Incremental backups• Image log

Principles of Information Systems, Sixth Edition

Preventing, Detecting, and Correcting Errors

Principles of Information Systems, Sixth Edition

Object-Oriented Design

Principles of Information Systems, Sixth Edition

Systems Controls

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

Principles of Information Systems, Sixth Edition

Request for Proposal

Principles of Information Systems, Sixth Edition

Financial Options

Principles of Information Systems, Sixth Edition

Cost/Benefit Analysis

Principles of Information Systems, Sixth Edition

Cost/Benefit Analysis

Principles of Information Systems, Sixth Edition

Evaluation Techniques

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

Principles of Information Systems, Sixth Edition

The Final Evaluation

Principles of Information Systems, Sixth Edition

Point Evaluation

Principles of Information Systems, Sixth Edition

Freezing Design Specifications

Principles of Information Systems, Sixth Edition

The Design Report

Principles of Information Systems, Sixth Edition

Systems Implementation

Principles of Information Systems, Sixth Edition

Systems Implementation

Principles of Information Systems, Sixth Edition

Acquiring Software: Make or Buy Software?

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

Principles of Information Systems, Sixth Edition

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

Principles of Information Systems, Sixth Edition

In-House Developed Software

• Chief programmer teams • The programming life cycle

Principles of Information Systems, Sixth Edition

Chief Programmer Teams

Principles of Information Systems, Sixth Edition

The Programming Life Cycle

Principles of Information Systems, Sixth Edition

Tools & Techniques for Software Development

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

Principles of Information Systems, Sixth Edition

Characteristics of Structured Programming

Principles of Information Systems, Sixth Edition

Structured Design and Programming

Principles of Information Systems, Sixth Edition

Structured Design and Programming

Principles of Information Systems, Sixth Edition

Structured Walkthroughs

Principles of Information Systems, Sixth Edition

Additional Implementation Activities

• Acquiring database and telecommunication systems

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

Principles of Information Systems, Sixth Edition

Additional Implementation Activities

• Installation• Testing

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

Principles of Information Systems, Sixth Edition

Testing

Principles of Information Systems, Sixth Edition

Start-Up Approaches

Principles of Information Systems, Sixth Edition

Start-Up Approaches

Principles of Information Systems, Sixth Edition

Systems Maintenance

Principles of Information Systems, Sixth Edition

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

Principles of Information Systems, Sixth Edition

Types of Maintenance

• Slipstream upgrade• Patch• Release• Version

Principles of Information Systems, Sixth Edition

The Financial Implications of Maintenance

Principles of Information Systems, Sixth Edition

The Relationship Between Maintenance and Design

Principles of Information Systems, Sixth Edition

Systems Review

Principles of Information Systems, Sixth Edition

Types of Review Procedures

Principles of Information Systems, Sixth Edition

Factors to Consider During Systems Review

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

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

Principles of Information Systems, Sixth Edition

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