The Information Systems Development Process Chapter 9

Chapter Objectives Understand the process used by organizations to manage the development of IS Describe each major phase of the system’s development life cycle Explain how organizations identify projects, assess feasibility, identify benefits and costs, and perform economic analysis of a system project

The Need for Structured Systems Development Systems Development –Process of designing, building and maintaining information systems Performed by systems analysts –Requires both managerial and technical expertise

The Evolution of Information Systems Development Early days –Techniques used to develop systems varied –Difficult to integrate large systems In response, IS professionals developed software engineering –Easier to train programmers and analysts to use common techniques –Results in more maintainable systems

Options for Obtaining Information Systems Build internally by IS staff Buy a pre-packaged system Hire an organization or consultant to custom-build a system –Outsourced Users/departments build their own custom systems for their individual needs –End-user development

Sources for IS

Information Systems Development in Action The problem decomposition process

The Role of Users in the Systems Development Process Systems analysts rely on information from system users Key to project success –A close and mutually respectful working relationship between analysts and users

Steps in the Systems Development Process System identification, selection, and planning System analysis System design System implementation System maintenance

Phase 1: System Identification, Selection, and Planning Undertake only those projects critical to mission, goals, and objectives Select a development project from all possible projects that could be performed Different evaluation criteria used to rank potential projects

Table 9.1 Sources of systems development projects and their likely focus. Project SourcePrimary Focus Top managementBroad strategic focus Steering committeeCross-functional focus Individual departments and business units Narrow, tactical focus Systems development group Integration with existing information system focus

Table 9.2 Possible evaluation criteria for classifying and ranking projects. Evaluation CriteriaDescription Strategic alignment The extent to which the project is viewed as helping the organization achieve its strategic objectives and long-term goals. Potential benefitsThe extent to which the project is viewed as improving profits, customer service, and so forth, and the duration of these benefits. Potential costs and resource avail. The number and types of resources the project requires and their availability. Project size / duration The number of individuals and the length of time needed to complete the project. Technical difficulty / risks The level of technical difficulty involved in successfully completing the project within a given time and resource constraint. Source Adapted from Hoffer, George, and Valacich Modern Systems Analysis and Design. 2d ed. Reading, Massachusetts: Addison Wesley Longman.

Assessing Project Feasibility Economic Technical Operational Schedule Legal and contractual Political

Table 9.3 Types of feasibility used when assessing an information systems project. Feasibility TypePurpose for Assessing EconomicTo identify the financial benefits and costs associated with the development project TechnicalTo gain an understanding of the development organization's capability to construct the proposed system OperationalTo gain an understanding of the degree to which and the likelihood that the proposed system solves the business problems or takes advantage of the opportunities outlined in the project request ScheduleTo gain an understanding of the likelihood that all potential timeframe and completion date schedules can be met Legal and contractual To gain an understanding of any potential legal ramifications of the construction of the system PoliticalTo gain an understanding of how key stakeholders within the organization view the proposed system Source Adapted from Hoffer, George, and Valacich Modern Systems Analysis and Design. 2d ed. Reading, Massachusetts: Addison Wesley Longman.

Identifying System Benefits Tangible benefits easily measured in dollars and certainty –Reduced personnel expenses –Lower transaction costs –Higher profit margins Intangible benefits difficult to measure –Improvement of employee morale –Reduction of waste creation

Identifying System Costs Tangible costs –Hardware –Labor –Employee training Intangible costs –Loss of customer goodwill –Loss of employee morale

Performing an Economic Analysis of a System Project Uses the concept of the time value of money –Compare present cash outlays to future expected returns Spreadsheet analysis –Net present value –Return on investment –Break-even analysis

Table 9.4 Commonly used economic cost- benefit analysis techniques. Name of TechniqueDescription of Technique Net Present Value (NPV)NPV uses a discount rate determined from the company's cost of capital to establish the present value of a project. The discount rate is used to determine the present value of both cash receipts and outlays. Return on Investment (ROI) ROI is the ratio of the net cash receipts of the project divided by the cash outlays of the project. Tradeoff analysis can be made between projects competing for investment by comparing their representative ROI ratios. Break-Even AnalysisThis technique finds the amount of time required for the cumulative cash flow from a project to equal its initial and ongoing investment. Source Adapted from Hoffer, George, and Valacich Modern Systems Analysis and Design. 2d ed. Reading, Massachusetts: Addison Wesley Longman.

Phase 2: System Analysis Gain a thorough understanding of an organization’s current way of doing things Determine system requirements –Interview users –Develop questionnaires –Watch the day-to-day activities of users Organize information using data, process, and logic-modeling tools

Modeling Organizational Data Systems analysts determine data needed to accomplish intended tasks Use data-modeling tools to depict the data Entity-Relationship Diagram –Relationships represented on diagram by lines drawn between entities

Entity-Relationship Diagram

Modeling Organizational Processes Data flows –Show the movement of data within an information system Processing logic –Represents the way data are transformed

Phase 3: System Design The proposed system is designed Elements designed include –Forms and reports –Interfaces and dialogs –Databases and files –Processing and logic

Designing Forms and Reports Forms –Collect data to input into system –Some pre-defined data with blank spaces for additional data Reports –Receive information from system –Static documents that summarize data

Designing Interfaces and Dialogs Text-based interfaces –Waits for a text command from the user Graphical user interfaces (GUI) –Provides user with icons and menus of choices –First introduced on Macintosh –Windows made GUI available to IBM- based machines

Designing Databases and Files Requires thorough understanding of the data and informational needs Uses data-modeling tools to create a conceptual data model

Designing Processing and Logic Steps and procedures that transform data into new or modified information Pseudo code –Text descriptions of detailed processing steps Structure charts –Break a large problems into smaller pieces Decision trees –Help design how the logic flows

Structure Chart

Decision Tree

Phase 4: System Implementation Transform the design into a working system –Software programming –Testing Prepare organization to use the new system –System conversion –Documentation –User training –Support

Software Programming and Testing Programming –Transforming the system design into a working computer system Testing –Developmental testing by programmers to assure that each module is error-free –Alpha testing by software testers to assess if it meets the design requirements of the users –Beta testing by actual system users to test with actual data

System Conversion, Documentation, Training and Support Conversion –Parallel conversion –Direct conversion –Phased conversion –Pilot conversion Documentation –User guides –User training –Installation procedures Training –In-house –Outside vendors Support –Install system –Consult on features –Set up user accounts –Provide demonstrations –Help with problems

Software Conversion Strategies

Table 9.6 User training options. Training OptionDescription TutorialOne person taught at one time by a human or by paper-based exercises CourseSeveral people taught at one time Computer-aided instruction One person taught at one time by the computer system Interactive training manuals Combination of tutorials and computer-aided instruction Resident expertExpert on call to assist users as needed Software help components Built-in system components designed to train and troubleshoot problems External sourcesVendors and training providers to provide tutorials, courses, and other training activities

Phase 5: System Maintenance Largest part of system development effort Maintenance process –Obtain maintenance request –Transform requests into changes –Design changes –Implement changes

Changing Maintenance Mix

Types of Maintenance Corrective –To repair flaws in the design, coding, or implementation Adaptive –To meet changing business needs Perfective –To improve processing performance Preventive –To reduce the chance of future system failure