Evaluating Alternatives for Requirements, Environment, and Implementation

1
Chapter 8

• Evaluating Alternatives for Requirements,
  Environment, and Implementation

2
Objectives

• Prioritize the system requirements based on the
  desired system scope and level of automation for
  the new system
• Describe the strategic decisions that integrate
  the target processing environment and the design
  approach 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
Project Management Perspective

• Scope
• Time
• Cost
• Quality

• Human resources
• Procurement
• Communications
• Risk

5
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 has
  been made

6
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

7
Selecting Alternatives

• Strategic plan
• Economic feasibility
• Schedule and resource feasibility
• Technological feasibility
• Operational, organizational, and cultural
  feasibility

8
Application Deployment Environment

• Concerns regarding
• Computer equipment
• Operating systems
• Networks
• Existing environment generally considered

9
Centralized Systems

• Single-computer
• Mainframe-based
• Limited by single machine capacity
• Clustered and multi-computer
• Group of computers to provide processing and data
  storage capacity
• Cluster acts as a single system
• Multi-computer group is less similar than
  clustered

10
Single, Clustered, and Multi-computer
Architectures Figure 8-3
11
Distributed Computing

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

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Network Configuration for RMOFigure 8-4
13
Client-Server Architecture with a Shared
PrinterFigure 8-5
14
Three-Layer ArchitectureFigure 8-6
Also known as Model-View-Controller (MVC)
15
N-Layer ArchitectureFigure 8-7
16
Enterprise Application Development

• Aspect of distributed computing
• Uses languages and tools suited for distributed
  implementation
• Good for applications on many platforms
• Java-Enterprise and VirtualStudio.net from
  Microsoft are examples

17
Internet

• Increasingly popular frameworks for implementing
  and delivering information systems
• B2B, B2C
• Internet
• SMTP, POP, IMAP
• FTP, Telnet, RPC
• WWW
• HTML, XML, HTTP
• Java, Javascript, VBScript, C

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Intranets and Extranets

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

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Internet as Application Platform

• Organized as client-server architecture
• Can use Web browsers as application interfaces
• Benefits
• Accessibility
• Low-cost communication
• Widely implemented standards

20
Negative Aspects of Internet Application Delivery

• Breaches of security
• Fluctuating reliability of network throughput
• Slow, throughput speeds to home users
• Volatile, changing standards

21
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

22
Choosing Implementation Alternatives

• System must be designed and programmed
• Variations on obtaining a system
• Facilitates management solutions
• Packaged, turnkey, ERP software systems
• Custom software development
• In-house development
• Selection dimensions
• Buy vs. build
• Software vs. development services

23
Implementation Alternatives Figure 8-11
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Identifying Criteria for Selection

• Comparisons difficult
• Different proposed systems have strengths in
  different areas
• Three areas to consider
• General requirements
• Technical requirements
• Functional requirements

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Partial Matrix of General Requirements Figure 8-12
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Partial Matrix of Functional Requirements
Function 8-13
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Partial Matrix of Technical Requirements for RMO
Figure 8-14
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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

29
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

30
Sample RFP Table of Contents From Figure 8-15
I. Introduction and Background II. Overview of
Need III. Description of Technical
Requirements IV. Description of Functional
Requirements
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Sample RFP Table of Contents From Figure 8-15
(cont.)
V. Description of General Requirements VI.
Requested Provider and Project Information VII.
Details for Submitting Proposal IV. Evaluation
Criteria and Process
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Benchmarking and Choosing a Vendor

• Observe in use or install trial version
• Evaluate the system against a standard
  (benchmark)
• Visit another company using particular system
• Develop contract

33
Presenting Results and Making Decisions

• Compile, organize, and present the alternatives
  and critical issues in an easy-to-understand but
  complete manner
• Final choice generally made by executive steering
  committee
• Format of documentation and presentation style
  varies with organization