Major Topics

• Information systems• Integrating New Technology• Phases of analysis and design• System maintenance• CASE tools

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

Categories

• Eight categories of Information systems:• Transaction processing systems (TPS)• Office automation systems (OAS)• Knowledge work systems (KWS)• Management information systems (MIS)• Decision support systems (DSS)• Expert systems (ES)• Group decision support systems (GDSS)• Executive support systems (EES)

Level of Categories

Figure 1.1 :The computeranalyst may be involved with any of or all these systems

Transaction Processing Systems (TPS)

• TPS are computerized information systems developed to process large amount of data for routine business transactions

• TPS reduces the time once required to perform the task manually

• TPS permits the organization to interact with external environment

• Example: Inventory or Payroll system

Office Automation Systems (OAS) and Knowledge Work Systems (KWS)

• Office Automation Systems (OAS):– Includes analysis of information so as to

transform data or manipulate it in some way before sharing or formally disseminating it

– Example: Word processing, spreadsheets, desktop publishing, electronic scheduling, communication through voice email, email and voice conference etc.

• Knowledge Work Systems (KWS):– Supports professionals (scientists, engineers,

doctors) by aiding them to create new knowledge– Example: Scientific analysis

Management Information Systems (MIS)

• MIS supports broader spectrum of organizational tasks than TPS, including decision analysis and decision making

• MIS users share a common database to access information

• MIS outputs information that is used in decision making

• Example: Account management system of Internet users

Decision Support systems (DSS)

• DSS is similar to the traditional MIS because they both depend on a database as a source of data

• Again, DSS departs from MIS in that DSS emphasizes the support of decision making in all its phases

• Example: Production increase decision by trend analysis

Expert Systems

• Expert system is a very special class of information system which is capable of generating solutions to problems with the aid of Artificial Intelligence (AI)

• An expert system (also called a knowledge based system) uses the knowledge of an expert for solving a particular problem

• Example: News Categorization software

Group Decision Support Systems (GDSS) and Computer Supported Collaborative Work Systems (CSCWS)

• Group Decision Support Systems – GDSS are intended to bring a group together

to solve a problem with the help of various support such as polling, questionnaires, brainstorming etc.

• Computer Supported Collaborative Work Systems– CDCWS is a more general term of GDSS– CSCWS may include software support called

“groupware” for team collaboration via network computers

• Example: video conferencing and web survey system

Executive Support Systems (ESS)

• It helps executives to make decisions on strategic level

• It may provide graphical representation and communication support at board meeting required to make strategic decision

• Example: New product launching decision

Integrating New Technologies

• New technologies are being integrated into traditional systems

• E-commerce 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 (m-commerce)

• Open source software

Integrating New Technologies

Figure 1.2: Integrating

Technologies

E-Commerce Application and Web Systems

Many businesses has found The Internet as their most favored way to pursue business growth because of the following

advantages:– Increase awareness of the availability of the

service, product, industry, person, or group– 24-hour access for users– Standardizing the design of interface– Creating a global system rather than remain

local

Enterprise Resource Planning (ERP) Systems

• Many organizations predicts potential benefits from the integration of many information systems existing on different management levels.

• ERP systems are designed to perform this integration

• Example: SAP, PeopleSoft and packages from Oracle

Systems for Wireless and Handheld Devices

• System analyst may be asked to design standard or wireless communication network that integrate voice, video and email into organizational intranet

• System analyst may also be asked to develop intelligent agents to assist the user of PDA or cell phone

• Wireless communication is referred as m-commerce (mobile commerce)

Open Source Software

• An alternative of traditional software development (where proprietary code is hidden from the users) is called open source software

• Open source software is free to distribute, share and modify its source code

• It makes money by providing services, customized program and support.

• Open source software are widely used in handheld and mobile devices.

• Example: Linux Operating System Apache Web Server

Nature of Analysis and Design

• A systematic approach to:– identify problems, opportunities, and

objectives; – analyze the information flows in

organizations; and – design computerized information

systems to solve a problem.

Systems Analyst

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

• Analysts are problem solvers, and require communication skills

• Analysts must be ethical with users and customers

Systems Development Life Cycle (SDLC):

• SDLC is a systematic approach for solving business problems.

• It is divided into seven phases.• Although each phase is presented

discretely, it is never accomplished as a separate step. Instead separate activity can occur simultaneously

Systems Development Life Cycle (SDLC):

Figure 1.3: Phases of SDLC

Phase 1: Identifying Problems, Opportunities and Objectives

• Personnel involved:– Analyst – User management– System management

• Activities:– Interviewing user management– Summarizing the knowledge obtained– Estimating the scope of the project– Documenting the results

• Output: Feasibility report containing problem definition and

objectives• Decision: Management then make decision whether to

proceed with the proposal or not

Phase 2: Determining Information Requirement

• Personnel Involved:– Information Analyst (IA)– User: operation managers and operation workers– Systems management

• Activity:– 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• Output: Analyst understands how the business

functions and gets enough information about the people, goals,

data and procedure involved

Phase 3: Analyzing System Needs

• Personnel Involved:– Analyst (IA)– User management– Systems management

• Activity:– Create data flow diagrams – Document procedural logic for data flow diagram

processes– Complete the data dictionary– Make semi-structured decisions (condition alternatives)– Prepare and present the system proposal– Recommend the optimal solution to management

Phase 4: Designing the Recommended System

• Personnel involved– Analyst– System designer– User: operation managers and operation workers– System management

• Activity:– Design the user interface

• Design output• Design input

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

Phase 5: Developing and Documenting Software

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

• Activity:– System analyst designs computer programs

using structure charts, and pseudo code etc.– Programmers write computer programs– Document software with help files, procedure

manuals, and Web sites with Frequently Asked Questions

Phase 6: Testing and Maintaining the System

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

• Activity:– Test and debug computer programs– Test the computer system– Enhance system– Maintenance of the system begins from this

phase

Phase 7: Implementing and Evaluating the System

• Personnel involved:– Analyst– System designer– Programmers– User: operation managers and operation

workers– Systems management

• Activity:– Train users– Analyst plans smooth conversion from old

system to new system– Purchase and install new equipment– Install system– Review and evaluate system

Maintenance

• Maintenance is performed for 2 reasons:– System maintenance

• Removing undetected errors, and• Enhancing existing software

– 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

Impact of Maintenance

Figure 1.4: Time spent on system maintenance

Impact of Maintenance

Figure 1.5: Resource consumption over the system life

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 and integrity

among life cycle phases• To assess the maintenance changes

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

Upper Case

Figure 1.6: The repository concept

Lower CASE

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

• Source code may usually be generated in several languages

• Advantages of generation code:– decrease development time– More programming language support– Free from program coding error

Traditional VS Case system development life cycle

Figure 1.7: Traditional VS Case SDLC

Reverse Engineering

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

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

Advantages of Reverse Engineering

– Reduced system maintenance time, freeing up time for new development

– 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

Object-Oriented Analysis and Design

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

• This includes not only data but the instructions about operations that manipulate the data

Alternative Methodologies

Alternatives to SDLC:– Prototyping– ETHICS– Soft System Methodology– Multiview

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