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

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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