Systems Design, Implementation, Maintenance, and Review

1
Systems Design, Implementation, Maintenance, and
Review

• Chapter 13

2
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.

3
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.

4
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.

5
Systems Design
6
Top Uses for New Systems in Various Industries
7
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

8
Physical Design

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

9
Special System Design Considerations

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

10
The Scope of Design
11
Procedures for Signing On
12
Interactive Processing
13
Emergency Alternate Procedures Disaster Recovery

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

14
Hardware Backup

• Disaster recovery plans
• Hot site
• Cold site

15
Software Database Backup

• Selective backups
• Incremental backups
• Image log

16
Preventing, Detecting, and Correcting Errors
17
Object-Oriented Design
18
Systems Controls

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

19
Request for Proposal
20
Financial Options
21
Cost/Benefit Analysis
22
Cost/Benefit Analysis
23
Evaluation Techniques

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

24
The Final Evaluation
25
Point Evaluation
26
Freezing Design Specifications
27
The Design Report
28
Systems Implementation
29
Systems Implementation
30
Acquiring Software Make or Buy Software?

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

31
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

32
In-House Developed Software

• Chief programmer teams
• The programming life cycle

33
Chief Programmer Teams
34
The Programming Life Cycle
35
Tools Techniques for Software Development

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

36
Characteristics of Structured Programming
37
Structured Design and Programming
38
Structured Design and Programming
39
Structured Walkthroughs
40
Additional Implementation Activities

• Acquiring database and telecommunication systems
• User preparation
• Hiring and training IS personnel
• Site preparation
• Data preparation

41
Additional Implementation Activities

• Installation
• Testing
• Unit testing
• System testing
• Volume testing
• Integration testing
• Acceptance testing

42
Testing
43
Start-Up Approaches
44
Start-Up Approaches
45
Systems Maintenance
46
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

47
Types of Maintenance

• Slipstream upgrade
• Patch
• Release
• Version

48
The Financial Implications of Maintenance
49
The Relationship Between Maintenance and Design
50
Systems Review
51
Types of Review Procedures
52
Factors to Consider During Systems Review

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

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

53
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