1. Chapter 8
Environments, Alternatives,
and Decisions

2. Objectives
Describe the strategic decisions that integrate the target processing environment and the design approach for the new system
Prioritize the system requirements based on the desired system scope and level of automation for the new system
Determine alternative approaches for system development

3. Objectives
Evaluate and select a development approach based on the needs and resources of the organization
Describe key elements of a request for proposal and evaluate vendors’ proposals for outsourced alternatives
Develop a professional presentation of findings to management

4. Overview
Explains transitional activities that refocus the project from discovery and analysis to solutions and design
Pivotal activities in project
Set direction for design and implementation
Primary objectives
Decide what to include in system scope
Determine what development method to use

5. Assessing Target Processing Environment
Determination of computer configuration, operating systems, and networks
Stable environment to support applications
Depends on IT strategic plan and existing environment

6. Centralized System Architectures
Single-computer
Mainframe-based
Limited by single machine capacity
Clustered and multicomputer
Group of computers to provide processing and data storage capacity
Cluster acts as a single system
Multicomputer group is less similar than clustered

7. Single, Clustered, and Multicomputer Architectures Figure 8-1

8. Distributed Computing
Distributes system across several computers and locations
Relies on computing networks for connectivity
Client-server architecture dominant model for distributed computing

9. Network Configuration for RMO Figure 8-2

10. Client-Server Architecture with a Shared Printer Figure 8-3

11. Three-Layer Architecture Figure 8-4

12. N-Layer Architecture Figure 8-5

13. Internet and WWW
Increasingly popular frameworks for implementing and delivering information systems
Internet
SMTP, POP, IMAP
FTP, Telnet, RPC
WWW
HTML, XML, HTTP
Java, Javascript, VBScript

14. Intranets and Extranets
Private networks using same TCP/IP protocol as the Internet
Limited to internal users
Extranets
Intranet that has been extended outside the organization

15. Internet as Application Platform
Organized as client-server architecture
Can use Web browsers as application interfaces
Benefits
Accessibility
Low-cost communication
Widely implemented standards

16. Negative Aspects of Internet Application Delivery
Security concerns
Reliability and network throughput variability
Throughput speeds to home users
Volatile, changing standards

17. Development and System Software Environments
Consists of standards and tools used in an organization
Important components
Language environment and expertise
Existing CASE tools and methodologies
Required interfaces to other systems
Operating system environment
Database management system environment

18. Existing Processing Environment at RMO
Table 8-1

19. Processing Environment
Alternatives for RMO
Table 8-2

20. Strategic Directions for the Processing Environment at RMO
Table 8-3

21. Deciding on Scope and Level of Automation
Scope determines which business functions will be included in system
Level of automation is how much automated computer support exists for functions included
Scope creep
Requests for addition of system functions after requirements have been defined and decision made

22. Scoping List of Potential Functions for RMO Table 8-4

23. Scoping List of Potential Functions for RMO Table 8-4 (continued)

24. Defining Level of Automation
Three levels
High
System takes over processing of business function
Medium
Midrange point which combines features from low and high alternatives
Low
Simple computer records keeping

25. Selecting Alternatives
Consult strategic plan
Revisit feasibility studies
Review implementation alternatives
Base on preliminary budget and resource constraints

26. Generating Alternatives for Implementation
System must be designed and programmed
Variations on obtaining a system
Facilitates management solutions
Packaged and turnkey software systems
Custom software development
In-house development
Selection dimensions
Buy vs. build
Software vs. development services

27. Implementation Alternatives
Figure 8-6

28. Identifying Criteria for Selection
May be like comparing apples and oranges
Different proposed systems have strengths in different areas
Three areas to consider
General requirements
Technical requirements
Functional requirements

29. Matrix of General Requirements for RMO
Table 8-7

30. Matrix of Technical Requirements for RMO
Table 8-8

31. Matrix of Functional Requirements for RMO
Table 8-9

32. Matrix of Functional Requirements for RMO
Table 8-9 (Continued)

33. Making the Selection After rating alternatives, choice can be made
Scores are tabulated and compared
RMO decided to use in-house development on most systems

34. Generating a Request for Proposal (RFP)
Formal document sent to vendors if in-house development not selected
States requirements and solicits proposed solutions
Considered a competitive contract offer

35. Sample RFP Table of Contents
Figure 8-7

36. Benchmarking and Choosing a Vendor
Observe in use or install trial version
Evaluation of system against a standard (benchmark)
Visit another company using system

37. Presenting Results and Making Decisions
Difficult task of compiling, organizing, and presenting alternatives and critical issues in easy-to-understand but complete manner
Executive steering committee generally makes final choice
Format of documentation and presentation style varies with organization