SAD Chapter1

Chapter 1Assuming the Role of the Systems Analyst

Systems Analysis and DesignKendall & KendallSixth Edition

2 MAJOR COMPONENTS OF

A SYSTEM DEVELOPMENT

1. System Design Is the process of planning a new business to

replace or complement the old.

2. System Analysis Is the process of gathering and interpreting

facts, diagnosing problems, and using the facts to improve the system.

Introduction to Systems Analysis and Design Page 1-43

DLSU-Dasmariñas-Cavite Systems Analysis and Design

What is System Analysis and Design?

Is the process of examining a business situation with the intent of improving it through better procedures and methods.

Is a series of processes which are systematically undertaken to improve a business through the use of computerized information system.



What is a Systems Analyst?

Studies the problems and needs of a business to determine how people, process, data, communications, and technology can best accomplish improvements for the business.

Is a business problems solver. Develops both an organization’s business

systems and its information system.



Business System – involves day-to-day business operations.

IS generates information to help managers solve problems and make intelligent decisions

Information as Organization Resource

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 as Organization Resource Page 4-43


Type of SystemsInformation systems fall into one of the following eight categories:

Transaction Processing System (TPS)Office Automation Systems (OAS)Knowledge Work Systems (KWS)Management Information SystemsDecision Support Systems (DSS)Expert Systems (ES)Group Decision Support Systems (GDSS)Executive Support Systems (ESS)

Type of Systems Page 5-43


Transaction Processing Systems

Developed to process large amounts of data for routine business transactions such as payroll and inventory.Eliminate the tedium of necessary operational transactionsReduce the time once required to perform these transactions manually although people still must input the data.Generate data used by managers as up-to-the minute information about what is happening in their companies.Computer-based versions of manual organization systems dedicated to handle the organization’s transactions.



Transactions

Individual simple events in the life of an organization that contain data about organizational activity.

Office Automation Systems

Support data workers who do not usually create new knowledge but rather analyze information as to transform data or manipulate it in some way before sharing it with. It includes word processing, spreadsheets, desktop publishing, electronic scheduling, and communication through voice mail, e-mail and video conferencing.The keyword that characterizes OA is communicationis intended to facilitate both oral and written communication.Capability to link people electronically for office work called virtual office, a term that suggests that office work can be done at virtually any geographically location as long as the work site is linked to one or more of the firm’s fixed locations.



Knowledge- Work System

Support professional workers such as scientists, engineers and doctors by aiding them in their efforts to create new knowledge and by allowing them to contribute it to their organization or to society bat large.



Management Information System

Supports a broader spectrum of organizational task.Helps unite some of the computerized information functions of a business.Requires people, software, hardware, shared database.Output is used for decision analysis and decision-making.



Decision-Support System

Emphasize the support in decision-making in all phases, the actual decision is still exclusive to the decision-maker.Experimental in nature, where the user tries different inputs to see their effects. The responses is used to try new inputs, and the process continues until a satisfactory result is obtained.



Expert SystemKnown as knowledge-based system, which captures and uses the knowledge of an expert for solving a problem experienced in a business.Uses the approaches of AISelects the best solution to a problem.Uses languages such as PROLOG, or LISP.



Group Decision Support System

Used in special rooms equipped in a number of different configurations, permit group members to interact with electronic support.Intended to bring a group together to solve a problem with the help of various supports such as polling, questionnaires, brainstorming, and scenario creation.Under general term computer supported collaborative work (CSCW) which include “groupware” for team collaboration.



Executive Support Systems

Help executives organize their interaction with the external environment by providing graphics and communications support in accessible places such as boardrooms or personal corporate offices.Extend and support the capabilities of executives, permitting them to make sense of their environments.



Kendall & Kendall 2005 Pearson Prentice Hall 14-43

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.


Integrating Technologies for Systems

E-Commerce Applications and Web Systems

Migrated to the WWW as to conceived and implemented as Web-based technologies.

Internet was the most favored strategy to pursue business growth.

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

Integrating Technologies for Systems Page 16-43



Enterprise Resource Planning Systems

Designed to perform integration of many information systems existing on different management levels and within different functions.




Systems for Wireless and Handheld Devices

The analyst designed standard or wireless communications networks that integrate voice, video, an e-mail into organizational intranets or industry extranets.




Open Source Software Open-Source software – is an

alternative to traditional software development where proprietary code is hidden from the users.

Stands for development model and philosophy of distributing software free and publishing its source code.

The source code can be studied, shared and modified by many users and programmers.




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.


Role of 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.

The Systems Development Life Cycle

is a systematic and orderly approach to solving business problems, and developing and supporting resulting information systems.

Traditional methodology used to develop, maintain, and replace information systems.

Evolution of process that is followed in implementing a computer-based information system.

It sometimes called an Applications Development Life Cycle

The SDLC Page 22-43



Phase1: Identifying Problems, Opportunities and Objectives

This stage is critical to the success of the rest of the object, because no one wants to waste subsequent time addressing the wrong problem.

The Analyst pinpoints problems. Opportunities are situations that the that the

analyst believes can be improve upon through the use of computerized information systems

The Analyst must discover what the business is trying to do to reach its objectives by addressing specific problems or opportunities.

The SDLC Page 24-43


Phase1: Identifying Problems, Opportunities and Objectives

Recognize the ProblemWhat is a problem?When is a problem advantageous?

Define the problemIs it the correct problem?

Set System ObjectivesHow will you solve the problem?

Identify system constraintsWhat are the boundaries/limitations of the system?

The SDLC Page 25-43


Steps:

Phase 2: Determining Information Requirements

Formal process of using research, interview, questionnaires, sampling and other techniques to collect information about system, requirements and preferences.SA team collects information on what the system should do from as many sources as possible: from users of the current system, from observing users and from existing reports, forms and procedures information gathering, data collection, data gathering

The SDLC Page 26-43


Phase 3: Analyzing System Needs

AnalysisThe study o the existing system for the purpose of designing a new or improved system

Announce the systems studyWhat is the reason of the study?

What benefits will the employees and the organization get from the study?

The SDLC Page 27-43


Steps:


Cont….

Organize the project teamWho does that?Define the information needs

- what kind of information will be needed?

- what tools should be used to get the information effectively?

Define the system performance criteriaPrepare the design proposal

The SDLC Page 28-43



Activities Identify and describe complete problem

specification Studies and documents the current system –

in terms of its problems, requirements for the new system

Prepares a list of requirements for the new system

Diagram the functions of the existing system necessary for the development of the new system

The SDLC Page 29-43


Phase 4: Designing the Recommended System

Design The determination of the process and data

that are required by a new system

Prepare the detailed systems designIdentify alternative system configurationsEvaluate alternative system configurationsSelect the best configurationPrepare the implementation proposalApprove or reject the proposal

The SDLC Page 30-43


Steps:

Phase 4: Designing the Recommended System

Design the user interface

Design OutputDesign input

Design system controlsDesign files and/or databaseProduce program specificationsProduce decision trees or tables

The SDLC Page 31-43


Phase 5: Developing and Documenting Software

Design compute programs using structure charts, Nassi-Schneiderman Charts, Data Flow Diagram and Pseudo codeWalkthrough program designWrite computer programsDocument software with help files, procedures manuals, and Web sites with Frequently Asked Questions

The SDLC Page 32-43


Phase 6: Testing and Maintaining the System

Test and debug computer programsTest the computer systemEnhance system

MaintenanceUse the systemAudit the system

Conduct a post implementation reviewMaintain the system

correct the errorsKeep the system currentImprove the system

The SDLC Page 33-43


Phase 7: Implementing and Evaluating the System

Implementation The acquisition and integration of the physical

and conceptual resources that produce a working system

Plan the implementationAnnounce the implementationObtain the hardware resourcesObtain the software resourcesPrepare the database

The SDLC Page 34-43


Steps:


Prepare the physical facilitiesEducate the participants and usersCut over to the new system

Conversion Methods:Immediate / Direct

Outright conversion from old system to new systemApplicable to small firms/systems

PhasedParallel

The SDLC Page 35-43


Cont…


PhasedThe new system put into use one part at a timePopular to large-scale systems

ParallelOld system is implemented simultaneously with the new oneGreatest assurance against failure but most expensive

The SDLC Page 36-43


Cont…


Phase 7 (Continued)

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


Rapid Application Development

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


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.


Education

SAD Chapter1