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
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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.

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Chapter Opening Case

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Information Systems Planning
Process

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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.”

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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

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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.

The Systems Approach
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• 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.

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

Systems Approach, SDLC
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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

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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

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Steps in the SDLC Process

SDLC Process (1)
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• 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 (2)
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• 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

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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

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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

SDLC Process (3)
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• 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.

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Systems Design
Example of System Specifications
User 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

SDLC Process (4)
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• 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

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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

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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

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System Conversion Strategies

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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

SDLC Process (5)
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• 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

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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.

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• 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

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• 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

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