Chapter 1 Assuming the Role of the Systems Analyst

Chapter 1Assuming the Role of the Systems

AnalystSystems Analysis and Design

Kendall & KendallSixth Edition

Chapter 1 The Systems Development

Environment

Modern Systems Analysis

and DesignFourth Edition

Jeffrey A. Hoffer Joey F. George

Joseph S. Valacich

Major Topics

• Information systems• Phases of analysis and design• System maintenance• CASE tools• Alternate methodologies

Kendall & Kendall 2005 Pearson Prentice Hall 1-3

Information

• Information is an organizational resource, which must be managed as carefully as other resources.

• Costs are associated with information processing.

• Information processing must be managed to take full advantage of its potential.


• Information Systems Analysis and Design– Complex organizational process whereby computer-based

information systems are developed and maintained• Application Software– Computer software designed to support organizational

functions or processes• Systems Analyst– Organizational role most responsible for analysis and

design of information systems

A Modern Approach to Systems Analysis and Design

• 1950s: focus on efficient automation of existing processes• 1960s: advent of 3GL, faster and more reliable computers• 1970s: system development becomes more like an

engineering discipline• 1980s: major breakthrough with 4GL, CASE tools, object

oriented methods• 1990s: focus on system integration, GUI applications,

client/server platforms, Internet• The new century: Web application development, wireless

PDAs, component-based applications

Categories Information systems fall into one of the following

eight categories:• Transaction processing systems (TPS).• Office automation systems (OAS).• Knowledge work systems (KWS).• Management information systems (MIS).• Decision support systems (DSS).• Expert systems (ES) and Artificial Intelligence (AI).• Group decision support systems (GDSS) and Computer-Supported

Collaborative Work Systems.• Executive support systems (EES).


Types of Information Systemsand Systems Development

• Transaction Processing Systems (TPS)– Automate handling of data about business activities (transactions)– Process orientation

• Management Information Systems (MIS)– Converts raw data from transaction processing system into

meaningful form– Data orientation

• Decision Support Systems (DSS)– Designed to help decision makers– Provides interactive environment for decision making– Involves data warehouses, executive information systems (EIS)– Database, model base, user dialogue

Types of Information Systemsand Systems Development (cont.)

New Technologies

New technologies are being integrated into traditional systems:

• Ecommerce uses the Web to perform business activities.• Enterprise Resource Planning (ERP) has the goal of

integrating many different information systems within the corporation.• Wireless and handheld devices, including mobile

commerce (mcommerce).• Open source software.



Advantages of Using the Web

The benefits of using the Web are:• Increasing awareness of the availability of the

service, product, industry, person, or group.• 24-hour access for users.• Standard interface design.• Creating a global system.


Nature of Analysis and Design

Systems analysis and design is a systematic approach to:– Identifying problems, opportunities, and

objectives.– Analyzing the information flows in organizations.– Designing computerized information systems to

solve a problem.


Systems Analyst

• Systems analysts act as:– Outside consultants to businesses.– Supporting experts within a business.– As change agents.

• Analysts are problem solvers, and require communication skills.

• Analysts must be ethical with users and customers.


Developing Information Systems and the SDLC

System Development Methodology– Standard process followed in an organization– Consists of:• Analysis• Design• Implementation• Maintenance

Systems Development Life Cycle (SDLC)

• Traditional methodology for developing, maintaining, and replacing information systems

• Phases in SDLC:– Planning– Analysis– Design– Implementation– Maintenance

Hoffer, George & Valacich

Traditional Waterfall SDLC

One phase begins when another completes, little backtracking and looping

Problems with Waterfall Approach

• System requirements “locked in” after being determined (can't change)

• Limited user involvement (only in requirements phase)

• Too much focus on milestone deadlines of SDLC phases to the detriment of sound development practices

Alternatives to Traditional Waterfall SDLC

• Prototyping• CASE tools• Joint Application Design (JAD)• Rapid Application Development (RAD)• Agile Methodologies• eXtreme Programming• ETHICS.• Project Champions.• Soft Systems Methodology.• Multi-view.

Standard and Evolutionary Views of SDLC


Systems Development Life Cycle

• The systems development life cycle is a systematic approach to solving business problems.

• It is divided into seven phases.• Each phase has unique activities.

• Kendall & Kendall



Phase 1

• Identifying:– Problems.– Opportunities.– Objectives.

• Personnel involved:– Analyst.– User management.– Systems management.


Phase 2

• Determining information requirements:– Interview management, operations personnel.– Gather systems/operating documents.– Use questionnaires.– Observe the system and personnel involved.

• Learn the who, what, where, when, and how, and the why for each of these.


Phase 2 (Continued)

• Personnel involved:– Analyst.– User management.– User operations workers.– Systems management.


Phase 3

• Analyzing system needs:– Create data flow diagrams. – Document procedural logic for data flow diagram

processes.– Complete the data dictionary.– Make semistructured decisions.– Prepare and present the system proposal.– Recommend the optimal solution to management.


Phase 3 (Continued)

• Personnel involved:– Analyst.– User management.– Systems management.


Phase 4

• Designing the recommended system:– Design the user interface.• Design output.• Design input.

– Design system controls.– Design files and/or database.– Produce program specifications.– Produce decision trees or tables.


Phase 4 (Continued)

• Personnel involved:– Analyst.– System designer.– User management.– User operations workers.– Systems management.


Phase 5

• Developing and documenting software:– Design computer programs using structure charts,

Nassi-Schneiderman charts, and pseudocode.– Walkthrough program design.– Write computer programs.– Document software with help files, procedure

manuals, and Web sites with Frequently Asked Questions.


Phase 5 (Continued)

• Personnel involved:– Analyst.– System designer.– Programmers.– Systems management.


Phase 6

• Testing and maintaining the system:– Test and debug computer programs.– Test the computer system.– Enhance system.


Phase 6 (Continued)

• Personnel involved:– Analyst.– System designer.– Programmers.– Systems management.


Phase 7

• Implementing and evaluating the system:– Plan conversion.– Train users.– Purchase and install new equipment.– Convert files.– Install system.– Review and evaluate system.


Phase 7 (Continued)

• Personnel involved:– Analyst.– System designer.– Programmers.– User management.– User operations workers.– Systems management.


System Maintenance

• System maintenance is: – Removing undetected errors, and– Enhancing existing software.

• Time spent on maintenance typically ranges from 48-60 percent of total time.


System Enhancements

Systems are enhanced for the following reasons:– Adding additional features to the system.– Business and governmental requirements change

over time.– Technology, hardware, and software are rapidly

changing.


The Heart of the Systems Development Process

Current practice combines analysis, design, and implementation into a single iterative and parallel process of activities

Joint Application Design (JAD)

• Structured process involving users, analysts, and managers

• Several-day intensive workgroup sessions• Purpose: to specify or review system

requirements

Rapid Application Development (RAD)

• Methodology to decrease design and implementation time• Involves: prototyping, JAD, CASE tools, and code generators

Prototyping

Iterative development process: Requirements quickly converted to a working systemSystem is continually revisedClose collaboration between users and analysts

Agile Methodologies

• Motivated by recognition of software development as fluid, unpredictable, and dynamic

• Three key principles– Adaptive rather than predictive– Emphasize people rather than roles– Self-adaptive processes

eXtreme Programming (XP)

• Extreme programming takes good software development practices and pushes them to the limit.

• It is based on:– Values.– Principles.– Core practices.


eXtreme Programming

• Short, incremental development cycles• Automated tests• Two-person programming teams• Coding and testing operate together• Advantages:– Communication between developers– High level of productivity– High-quality code

Extreme Programming (XP) (Continued)

• Extreme programming values are:– Communication.– Simplicity.– Feedback.– Courage.


Object-Oriented Analysis and Design

• Object-oriented (O-O) analysis and design is used to build object-oriented programs.

• O-O programming examines the objects of a system.

• Objects are grouped into classes for optimal reuse and maintainability.


• Based on objects rather than data or processes• Object: a structure encapsulating attributes and

behaviors of a real-world entity• Object class: a logical grouping of objects sharing the

same attributes and behaviors• Inheritance: hierarchical arrangement of classes

enable subclasses to inherit properties of superclasses

The Unified Modeling Language

• The Unified Modeling Language (UML) is an industry standard for modeling object-oriented systems.

• It breaks down a system into a use case model.


Rational Unified Process (RUP) involves an iterative, incremental approach to systems development

Rapid Application Development

Rapid Application development (RAD) is an object-oriented approach to systems development.



CASE Tools

– CASE tools are automated, microcomputer-based software packages for systems analysis and design.

– Four reasons for using CASE tools are:• To increase analyst productivity.• Facilitate communication among analysts and users.• Providing continuity between life cycle phases.• To assess the impact of maintenance.


CASE Tools

Computer-Aided Software Engineering• Software tools providing automated support

for systems development• Project dictionary/workbook: system

description and specifications• Diagramming tools• Example products: Oracle Designer, Rational

Rose, Visible Analyst

CASE Tool Categories

CASE tools may be divided into several categories– Upper CASE (also called front-end CASE) tools,

used to perform analysis and design.– Lower CASE (also called back-end CASE). These

tools generate computer language source code from CASE design.

– Integrated CASE, performing both upper and lower CASE functions.


Upper CASE

Upper CASE tools:– Create and modify the system design.– Store data in a project repository.– The repository is a collection of records, elements,

diagrams, screens, reports, and other project information.

– These CASE tools model organizational requirements and define system boundaries.


Lower CASE

• Lower CASE tools generate computer source code from the CASE design.

• Source code may usually be generated in several languages.


Advantages of Generating Code

– Time to develop new systems decreases.– The time to maintain generated code is less than to

maintain traditional systems.– Computer programs may be generated in more than

one language.– CASE design may be purchased from third-party

vendors and tailored to organizational needs.– Generated code is free from program coding errors.



Reverse Engineering

• Reverse engineering is generating the CASE design from computer program code.

• Source code is examined, analyzed, and converted into repository entities.


Reverse Engineering (Continued)

• Reverse engineering produces (depending on the tool set used):– Data structures and elements, describing the files,

records, and field.– Screen designs, if the program is online.– Report layouts for batch programs.– A structure chart showing the hierarchy of the

modules in the program.– Database design and relationships.


Advantages of Reverse Engineering

Reverse Engineering has the following advantages:– Reduced system maintenance time.– Program documentation is produced for loosely

documented programs.– Structured programs may be generated from

unstructured, older programs.– Future system maintenance is easier to implement.– Unused portions of programs may be eliminated.


Date post:	08-Feb-2016
Category:	Documents
Upload:	rod
View:	41 times
Download:	1 times

Chapter 1 Assuming the Role of the Systems Analyst

Documents