principles of information systems, sixth edition 1 systems design, implementation, maintenance, and...

Principles of Information Systems, Sixth Edition

1

Systems Design, Implementation, Maintenance, and Review

Chapter 13


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Chapter 13 Outline

• Systems Design

• Systems Implementation

• Systems Maintenance

• Systems Review


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Systems Design


4

Top Uses for New Systems in Various Industries


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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


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Physical Design

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


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Special System Design Considerations

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


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The Scope of Design


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Procedures for Signing On


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Interactive Processing


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Emergency Alternate Procedures & Disaster Recovery

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


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Hardware Backup

• Disaster recovery plans• Hot site• Cold site


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Software & Database Backup

• Selective backups• Incremental backups• Image log


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Preventing, Detecting, and Correcting Errors


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Object-Oriented Design


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Systems Controls

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


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Request for Proposal


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Financial Options


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Cost/Benefit Analysis


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Cost/Benefit Analysis


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Evaluation Techniques

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


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The Final Evaluation


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Point Evaluation


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Freezing Design Specifications


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The Design Report


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Systems Implementation


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Systems Implementation


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Acquiring Software: Make or Buy Software?

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


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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


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In-House Developed Software

• Chief programmer teams • The programming life cycle


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Chief Programmer Teams


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The Programming Life Cycle


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Tools & Techniques for Software Development

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


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Characteristics of Structured Programming


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Structured Design and Programming


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Structured Design and Programming


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Structured Walkthroughs


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Additional Implementation Activities

• Acquiring database and telecommunication systems

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


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Additional Implementation Activities

• Installation• Testing

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


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Testing


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Start-Up Approaches


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Start-Up Approaches


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Systems Maintenance


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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


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Types of Maintenance

• Slipstream upgrade• Patch• Release• Version


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The Financial Implications of Maintenance


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The Relationship Between Maintenance and Design


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Systems Review


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Types of Review Procedures


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Factors to Consider During Systems Review

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

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


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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


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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.


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• 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.


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• 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.


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End of Chapter 13

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