Cis 2303 lo1 part 1_weeks_1_2 - student ver

Systems Analysis and DesignCIS 2303

Learning Outcome 1:

Describe the evolution of software development with emphasis on the processes that outline different methodologies. - Ch. 1

Learning Objectives 1. Introduction to Information Systems

Discuss the impact of information technology on business strategy and success

Define an information system and describe its components

Explain how profiles and models can represent business functions and operations

2. Systems Development Methods

3. Overview of Structured Analysis and SDLC

4. SDLC MODEL Phases

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1. Introduction to Information Systems

A. Chapter Introduction Case: Mountain View College Bookstore

B. Discuss the impact of information technology on business strategy and success

C. What is IT?

D. What is Systems analysis and design?

E. Define an information system and describe its components

F. Explain how profiles and models can represent business functions and operations

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B. Impact of IT on business strategies

• Companies use information as a weapon in the battle to increase productivity, deliver quality products and services, maintain customer loyalty, and make sound decisions

• Information technology can mean the difference between success and failure

• Figure 1-1

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C. What is IT?

Information Technology (IT) ◦Combination of ___________and

___________ products and ___________ that ___________ use to manage, access, communicate, and share ____________

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companies

hardware

information

software

services

D. Systems Analysis and Design

Systems Analysis and Design Step-by-step process for developing high-

quality information systems

Roles of the Systems Analyst Plan, develop, and maintain information

systems

See the next slides to have a detailed list of the Systems analyst.

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Roles of the Systems Analyst

The primary objective of any system analyst is to identify the need of the organization by acquiring information by various means and methods.

The system analyst has to coordinate with the:◦_________________, ◦_________________, ◦___________________________________

____________________________________.

Following are the tasks performed by the systems analyst:

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Tasks Performed By the Systems Analyst

Defining Requirement:

Prioritizing Requirements

Gathering Facts, data and opinions of Users

Evaluation and Analysis

Drawing Specifications

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Defining Requirement: The basic step for any system

analyst is to understand the requirements of the users. This is achieved by various fact finding techniques like:◦interviewing, ◦observation, ◦questionnaire ◦etc.

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Prioritizing RequirementsNumber of users use the system in the

organization, and each one has a different requirement and retrieves different information.

Due to certain limitations in computing capacity it may not be possible to satisfy the needs of all the users.

Hence it is important to create list of priorities according to users requirements.

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Gathering Facts, data and opinions of Users

After determining the necessary needs and collecting useful information, the analyst starts the development of the system with active cooperation from the users of the system.

Time to time, the users update the analyst with the necessary information for developing the system.

The analyst while developing the system continuously consults the users and acquires their views and opinions.

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Discussion

As a System’s Analyst, why do you need to continuously consult the users and acquires their views and opinions?

Evaluation and AnalysisThe analyst must constantly

change and modify the system to make it better and more user friendly for the users

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Drawing SpecificationsThe analyst must draw certain

specifications which will be useful for the manager.

The analyst should lay the specification which can be easily understood by the manager and they should be purely non-technical.

The specifications must be in detailed and in well presented form 14

E. Information System Components

• Information systems have five key components: • hardware, • software,• data, • processes, and • People

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E. Information System Components –Cont.

1. Hardware ◦Is the physical layer of the

information system◦Moore’s Law

2. Software◦System software◦Application software

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E. Information System Components –Cont.

3. Data ◦ Tables store data◦ Linked tables work

together to supply data

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E. Information System Components –Cont.

4. Processes ◦ Describe the tasks

and business functions that users, managers, and IT staff members perform to achieve specific results

5. People◦ Stakeholders◦ Users, or end users

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Information System Components Exercise

Microsoft Windows

Number of Hours

Worked

Register a Student

Microsoft Excel

Storage Server

Withdraw Cash

System Users

Employee No

HardwareSoftwareDataProcesses People

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2. Systems Development Methods

Systems Development Methods◦ Structured Analysis◦ Object-Oriented Analysis◦ Agile/adaptive methods

In this course, we will only concentrate on the Structured Analysis.

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3. Overview of Structured Analysis and SDLC Model

A traditional systems development technique that is time-tested and easy to understand.

Uses a series of phases, called the systems development life cycle (SDLC ), to plan, analyze, design, implement, and support an information system.

A Predictive approachStructured analysis is called a process-centered

technique

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3. Overview of Structured Analysis and SDLC Model –Cont.

In the waterfall model , the result of each phase is called a deliverable , or end product , which flows into the next phase.

Disadvantage in the built-in structure of the SDLC, because the waterfall model does not emphasize interactivity among the phases

This criticism can be valid if the SDLC phases are followed too rigidly

Adjacent phases usually interactSee Figure 1-27

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4. SDLC MODEL Phases

The SDLC model usually includes five steps

1) Systems planning2) Systems analysis3) Systems design4) Systems implementation5) Systems support and security

See Figure 1-27 in the next slide

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Figure 1-27: SDLC – The Waterfall Model

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Phase 1Systems planning

Phase 2Systems Analysis

Phase 3Systems Design

Phase 4Implementation

Phase 5Operation, Support

& Security

Planning and Modeling a Systems Development Project

Systems planning◦ Systems request◦ Purpose of this phase is to perform a preliminary

investigation whose key part is a feasibility study

Systems Analysis◦ The purpose is to build a logical model of the new

system. ◦ The first step is requirements modeling , where

you investigate business processes and document what the new system must do to satisfy users.

◦ Requirements modeling continues the investigation that began during the systems planning phase.

◦ Deliverable is the System requirements document which describes management and user requirements, costs and benefits, and outlines alternative development strategies.

PreliminaryInvestigation

Report

System Requirements

Document

Planning and Modeling a Systems Development Project

Systems Design◦ The purpose is to create a physical model that will

satisfy all documented requirements for the system.

◦ At this stage, you design the user interface and identify necessary outputs, inputs, and processes

◦ Deliverable is system design specification◦ Management and user involvement is critical

Systems Implementation◦ New system is constructed◦ Programs are written, tested, and documented, and

the system is installed◦ The objective is to deliver a completely functioning

and documented information system◦ Final preparations include converting data to the

new system's files and training users◦ This stage also includes an assessment, called a

systems evaluation

SystemDesignSpecs

FunctionalIS

Planning and Modeling a Systems Development Project

Systems Operation, Support, and Security◦ A well-designed system must be secure,

reliable, maintainable, and scalable◦ After several years of operation,

systems need extensive changes ◦ During this phase, the IT staff

maintains, enhances, and protects the system

◦ Security controls safeguard the system from both external and internal threats

◦ Most information systems need to be updated significantly or replaced after several years of operation

OperationalIS

I am designing the user interface of the system and the database that the system will use to store the user’s data! (______________________)

I am gathering the system requirements of the user through interviews, questionnaires, and observation at work! (______________________)

I am adding more forms and reports to the system that users asked me to add because they have new requirements!

(______________________) I am doing a Preliminary Investigation and a

Feasibility Study to investigate the “Worthiness” of the proposed system! (______________________)

I am writing the programming code of the system! (______________________) 28

Which SDLC Model Phase am I in?!

Review Questions(Answer on BB-Learn)

What is IT, and why is it important to a business?

What is the role of the System Analyst?What are three different Systems Development

Methods? What are the different functions of a business?What are the phases of the SDLC?What are the different activities within an IT

department?What is an IS, and what are its components?Who develops IS?