Session#6; information systems development

N.Karami, MIS-Spring 2012

Management Information Systems

IS Development

Graduate School of

Management & Economics

1

Information Systems

Development



IS Development

Graduate School of


2

Learning Objectives

• Describe the IT planning process.

• Describe IS development & system approach

• Describe Strategies for Acquiring IT Applications

• Describe the SDLC and its advantages and

limitations.

• Describe the major alternative methods and tools for

building information systems.



IS Development

Graduate School of


3

Chapter Opening Case

http://www.zappos.com/




http://www.opensource.org/

http://www.opensource.org/



IS Development

Graduate School of


4

Information Systems Planning

Process



IS Development

Graduate School of


5

Information Systems Planning (continued)

• IT architecture delineates the way an

organization’s information resources should be

used to accomplish its mission.

• Both are inputs in developing the IT strategic

plan:

“A set of long-range goals that describe

the IT infrastructure and major IT initiatives

needed to achieve the goals of the

organization.”



IS Development

Graduate School of


6

IT Operational Plan

• Consists of a clear set of projects that the IT department and functional area managers will execute in support of the IT strategic plan

• Contains the following elements:

– Mission

– IT environment

– Objectives of the IT function

– Constraints of the IT function

– Application portfolio

– Resource allocation and project management



IS Development

Graduate School of


7

IS Development

• When the systems approach is applied to

the development of an information systems solution

to business problems, it is called information

systems development or application

development.



IS Development

Graduate School of


8

• During the late 1960s/early 1970s, interest in systematic

problem solving strengthened.

• The systems approach to problem solving applied to the

development of information system solutions to business

problems.

• Systems approach: A series of problem-solving steps

that ensure the problem is first understood, alternative

solutions are considered, and the selected solution works.

The Systems Approach



IS Development

Graduate School of


9

Developing an information system solution is based on the problem-solving process.

Developing an Information

System Solution



IS Development

Graduate School of


10

Strategies for Acquiring IT

Applications

• Options for Obtaining Information Systems

• Build your own

– Insourcing: Using IT specialists within your organization

– Selfsourcing: Using knowledge workers such as yourself

• Outsourcing: Using another organization

– Buy a prepackaged system

– Outsource development to a 3rd party

Systems Approach, SDLC



IS Development

Graduate School of


11

The Systems Development

Lifecycle

• Systems development life cycle (SDLC) is an

application of the systems approach to the

development of an information system.

• Oldest method for building information systems

• Phased approach with formal stages

• Waterfall approach

• Formal division of labor

• Used for building large, complex systems

• Time consuming and expensive to use



IS Development

Graduate School of


12

Steps in the SDLC Process



IS Development

Graduate School of


13

• Systems Investigation

– The first step in the systems development

process

– May involve consideration of proposals

generated by a business/IT planning process

– Also includes the preliminary feasibility study

of proposed information system solutions:

• Technical feasibility

• Economic feasibility

• Organizational feasibility

• Behavioral feasibility

SDLC Process (1)



IS Development

Graduate School of


14

• Systems Analysis

– An in-depth study of end user information needs

• It produces the functional requirements used as the

basis for the design of an IS

– It typically involves a detailed study of the

• Information needs of a company and end users

• Activities, resources, and products of one or more of

the information systems currently being used

• Information system capabilities required to meet the

information needs of business stakeholders

SDLC Process (2)



IS Development

Graduate School of


15

Systems Analysis (Continued)

• Logical Analysis

– A logical model is a blueprint of the current system

• It displays what the current system does, without regard to how it

does it

• It allows an analyst to understand the processes, functions, and data

associated with a system without getting bogged down with

hardware and software

• Functional Requirements

– This step of systems analysis is one of the most difficult

• Determine what type of information each business activity requires

• Try to determine the information processing capabilities required for

each system activity

• The goal is to identify what should be done, not how to do it



IS Development

Graduate School of


16

Systems Analysis

Example of Functional Requirements

• User Interface: automatic entry of product data and easy-to-use data entry screens for Web customers

• Processing: fast, automatic calculation of sales totals and shipping costs

• Storage: fast retrieval and update of data from product, pricing, and customer databases

• Control: signals for data entry errors and quick e-mail confirmation for customers



IS Development

Graduate School of


17

• Systems Design

– Deliverable is the technical design (system specifications)

that specifies:

• System outputs, inputs, user interfaces.

• Hardware, software, databases, telecommunications,

personnel & procedures.

• Blueprint of how these components are integrated.

SDLC Process (3)



IS Development

Graduate School of


18

Systems Design

Example of System SpecificationsUser interface

specifications

Use personalized screens that welcome repeat Web customers

and that make product recommendations

Database

specifications

Develop databases that use object/relational database

management software to organize access to all customer and

inventory data and to multimedia product information

Software

specifications

Acquire an e-commerce software engine to process all

e-commerce transactions with fast responses, i.e., retrieve

necessary product data and compute all sales amounts in less

than one second

Hardware

and network

specifications

Install redundant networked Web servers and sufficient high-

bandwidth telecommunications lines to host the company e-

commerce website

Personnel

specifications

Hire an e-commerce manager and specialists and a webmaster

and Web designer to plan, develop, and manage e-commerce

operations



IS Development

Graduate School of


19

• Implementing new systems

– The systems implementation process involves

• Hardware and software acquisition

• Software development or modification

• Testing of programs and procedures

• Conversion of data resources

• Conversion alternatives (converting from the old system to

the new system)

• Education/training of end users and

specialists who will operate the new system

SDLC Process (4)



IS Development

Graduate School of


20

Systems Implementation

System Testing• Testing checks to see if the computer code will

produce the expected and desired results under certain

conditions.

• System testing may involve

– Testing and debugging software

– Testing website performance

– Testing new hardware



IS Development

Graduate School of


21


Data Conversion

• Data conversion includes

– Converting data elements from the old database to

the new database

– Correcting data errors

– Filtering out unwanted data

– Consolidating data from several databases

– Organizing data into new data subsets

• Improperly organized and formatted data is a

major cause of implementation failures



IS Development

Graduate School of


22


System Conversion Strategies



IS Development

Graduate School of


23


Training

• End users must be trained to operate a new

business system or its implementation will fail

– May involve only activities, such as data entry,

or all aspects of system use

– Managers and end users must understand how the

new technology impacts business operations



IS Development

Graduate School of


24

• Systems Maintenance

– Audits are performed to assess the system’s

capabilities and to determine if it is being used

correctly.

– There are four basic categories of system

maintenance

• Corrective: fix bugs and logical errors

• Adaptive: add new functionality

• Perfective: improve performance

• Preventive: reduce chances of failure

SDLC Process (5)



IS Development

Graduate School of


25

Alternative Methods & Tools for

Systems Development (1)• Prototyping

• Joint application design (JAD)

– A group –based tool for collecting user requirements and

creating system designs.

• Computer-assisted software engineering

tools (CASE)

– A development approach that uses specialized tools to

automate many of the tasks in the SDLC; upper CASE tools

in SDLC automate the early stages of the SDLC, and lower

case tools automate the later stages.



IS Development

Graduate School of


26


Systems Development (2)• Integrated computer-assisted software

engineering tools (ICASE)

– CASE tools that provide links between upper CASE and

lower CASE tools.

• Rapid application development (RAD)

• End-user development

– A development method that has the actually user develop

their own application(s) for use.

• Component-based development



IS Development

Graduate School of


27


Systems Development (3)

• Object-oriented development

– Based on concepts of class and inheritance

– Component-based development and Web services

• Object-Oriented Analysis & Design (OOA&D)

– Data and processing are integrated (logical and

physical model)

Session#6; information systems development

Documents

Transcript of Session#6; information systems development