Chapter 8 Environments, Alternatives, and Decisions

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

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

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

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

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

Single, Clustered, and Multicomputer Architectures Figure 8-1

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

Network Configuration for RMO Figure 8-2

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

Three-Layer Architecture Figure 8-4

N-Layer Architecture Figure 8-5

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

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

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

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

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

Existing Processing Environment at RMO Table 8-1

Processing Environment Alternatives for RMO Table 8-2

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

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

Scoping List of Potential Functions for RMO Table 8-4

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

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

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

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

Implementation Alternatives Figure 8-6

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

Matrix of General Requirements for RMO Table 8-7

Matrix of Technical Requirements for RMO Table 8-8

Matrix of Functional Requirements for RMO Table 8-9

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

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

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

Sample RFP Table of Contents Figure 8-7

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

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