COMSCI 2201 (MAM ISAY) 1ST SEM

• Complex organizational process

• Used to develop and maintain computer-based information systems

• Used by a team of business and systems professionals

Information Systems Analysis and Design

Computer software designed to support organizational functions or processes

Application Software

Organizational role most responsible for analysis and design of information systems

Systems Analyst

What are the organizational approach to system analysis and design

• methodologies

• techniques

• and tools

In __ , focus on efficient automation of existing processes

1950

In __ , advent of procedural third generation languages (3GL) faster and more reliable computers

1960

In __, system development becomes more like an engineering discipline

1970

In__ major breakthrough with 4GL, CASE tools, object-oriented methods

1980

In__ , focus on system integration, GUI applications, client/server platforms, internet

1990

The__, Web application development, wireless PDAs and smartphones, component-based application services

The New Century

a standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, and maintain information systems.

System Development Methodology

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

System Development Life Cycle (SDLC)

What are the Phases in SDLC

• Planning

• Analysis

• Design

• Implementation

• Maintenance

What are the two views of SDLC?

• System Development Life Cycle

• Evolutionary model

System Development Life Cycle View

Evolutionary model View

an organization’s total information system needs are identified, analyzed, prioritized, and arranged.

Planning

system requirements are studied and structured.

Analysis

a description of the recommended solution is converted into logical and then physical system specifications

Design

Two types of Design

• Logical Design

• Physical Design

all functional features of the system chosen for development in analysis are described independently of any computer platform.

Logical design –

the logical specifications of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished.

Physical design

the information system is coded, tested, installed and supported in the organization.

Implementation

an information system is systematically repaired and improved.

Maintenance

System Development Life Cycle

Product of SDLC

Microsoft’s Security Development Lifecyle (SDL)

The Heart of the Systems Development Process

One phase begins when another completes, with little backtracking and looping

Traditional Waterfall SDLC

Problems with Waterfall Approach

• Feedback ignored, milestones lock in design specs even when conditions change.

• Limited user involvement (only in requirements phase).

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

Different Approaches to Improving Development

• CASE Tools

• Agile Methodologies

• eXtreme Programming

CASE Tools stands for?

Computer Aided Software Engineering ( CASE Tools)

are used to automate some task in system development of information systems e.g. generating documentation and diagrams. CASE tools can also be used for code generation

CASE Tools

Types of CASE Tools

• Upper Case tools

• Lower Case tools

It is Also known as Analyst’s workbench

UPPER CASE TOOLS

it is also known as Programmer’s workbench

Lower Case tooos

Product of CASE Tools

it enable graphical representation.

Diagramming tools

it s help prototype how systems “look and feel”.

Computer displays and report generator

automatically check for consistency in diagrams, forms, and reports.

Analysis tools

it provides integrated storage of diagrams, reports, and project management specifications.

central repository

standardize technical and user documentation.

Documentation generators

it enables automatic generation of programs and database code directly from design documents, diagrams, forms, and reports.

Code generators

what are the CASE TOOLS

• Diagramming tools

• Computer displays and report generators

• Analysis tools

• central repository

• Documentation generators

• Code generators

Example of CASE Usage within the SDLC

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

Agile Methodologies

What are the 3 key Principle of Agile Methodologies

• Adaptive rather than predictive

• Emphasize people rather than roles

• Self-adaptive processes

Agile Methodology

Agile Methodology Sample

Kanban Card

Scrum

Agile Manifesto

We are uncovering better ways of developing software by doing it and helping others do it.

When to Use Agile Methodologies

If your project involves:

• Unpredictable or dynamic requirements

• Responsible and motivated developers

• Customers who understand the process and will get involved

What are the five critical factors that distinguish agile and traditional approaches to system development

• Size

• Criticality

• Dynamism

• Personnel

• Culture

• Short, incremental development cycles

• Focuses on automated tests

• Two-person programming teams

• Coding, testing, listening, designing

eXtreme Programming

Planning/Feedback Loops

It combines data and processes (called methods) into single entities called __

objects.

Its goal is to make systems elements more reusable, thus improving system quality and the productivity.

Object-Oriented Analysis and Design

allows the creation of new classes that share some of the characteristics of existing classes.

Inheritance

ORIGINS OF SOFTWARE

The first source considered is __, in which all or part of an organization’s information systems, their development, and their maintenance are given over to another organization.

outsourcing

six different sources of software:

1) Information technology services firms;

2) Packaged software providers;

3) Vendors of enterprise-wide solution software;

4) Cloud-computing;

5) Open-source software;

6) The organization itself when it develops software in-house.

Driver for IS acquisition

If one organization develops or runs a computer application for another organization, that practice is called ___

outsourcing

The practice of turning over responsibility for some or all of an organization’s information systems applications and operations to an outside firm.

Outsourcing

Why would an organization outsource its information systems operations?

• cost-effectiveness

• freeing up internal resources

• increasing the revenue potential of the organization

• reducing time to market

• increasing process efficiencies,

• outsourcing noncore activities.

Outsourcing Companies

If a company needs an information system but does not have the expertise or the personnel to develop the system in-house, and a suitable off-the-shelf system is not available, the company will likely consult an___

information technology services firm

it help companies develop custom information systems for internal use, develop, host, and run applications for customers, or they provide other services.

INFORMATION TECHNOLOGY SERVICES FIRMS

Outsourcing Companies

PACKAGED SOFTWARE PRODUCERS

INFORMATION TECHNOLOGY SERVICES FIRMS

Some of the largest computer companies in the world are companies that produce software exclusively.

PACKAGED SOFTWARE PRODUCERS

Software companies develop what are sometimes called___

prepackaged or off-the-shelf systems

Also known as enterprise resource planning (ERP) systems

ENTERPRISE SOLUTIONS SOFTWARE

It consists of a series of integrated modules which support an individual, traditional business function.

ENTERPRISE SOLUTIONS SOFTWARE

It refers to the provision of applications over the Internet, where customers do not have to invest in the hardware and software resources needed to run and maintain the applications.

CLOUD COMPUTING

BENEFITS ON USING CLOUD COMPUTING

• Freeing internal IT staff;

• Gaining access to applications faster than via internal development;

• Achieving lower cost access to corporate-quality applications.

It is freely available, not just the final product but the source code itself.

OPEN SOURCE SOFTWARE

it performs the same functions as commercial software, such as operating systems, e-mail, database systems, web browsers, and so on.

OPEN SOURCE SOFTWARE

OPEN SOURCE SOFTWARE

it has become a progressively smaller piece of all systems development work that takes place in and for organizations.

IN-HOUSE DEVELOPMENT

__ involving some purchased and some in-house software components are common.

Hybrid solutions

– comparing the cost of developing the same system in-house with the cost of purchasing or licensing the software package.

Cost

– tasks the software can perform and the mandatory, essential, and desired system features.

Functionality

CHOOSING OFF-THE-SHELF SOFTWARE

– A document provided to vendors that asks them to propose hardware and system software that will meet the requirements of a new system.

Request for proposal (rFP)

two different development technologies

• object-oriented development

• component-based development

REUSE

FOUR APPROACHES TO REUSE