Transcript Chapter 14: Information Systems Development

System Development Life Cycle (SDLC)
CIS 105
Topics
List and describe the classic functions of
managers: planning, organizing, directing,
and controlling
Define “system,” “analysis,” and “design”
Describe the principal functions of the systems
analyst
List and describe the phases of the systems
development life cycle (SDLC)
Describe various data-gathering and analysis tools
List and describe various system testing methods
List and describe various system conversion
methods
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Classic Management Functions
Planning – devising plans for the organization
and setting goals to achieve the plan
Organizing – deciding how to use the
organization’s resources and includes hiring
and training workers
Directing – guiding employees to perform their
work in a way that supports the organization’s
goals
Controlling – monitoring the organization’s
progress toward reaching its goals
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Levels of Management
Strategic level
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Long range
Primary function: planning
Tactical level

Primary functions –
organizing and staffing
Operational level

Primary functions –
directing and controlling
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System Development Life Cycle (SDLC)
Managers at each level need information
to help them make decisions, so they rely
on some type of Information System.
How are Information Systems purchased
or built?
The process which includes analyzing the
system requirements to designing and
implementing a new system is called the
System Development Life Cycle (SDLC).5
Systems
Analysis
Design
System – an organized set of related components
established to accomplish a certain task

Computer system – a system that has a computer as one of
its components
Analysis - Studying an existing system to determine
how it works and how it meets users’ needs

Typically happens as a result of some impetus for change,
combined with the authority to make the change
Design - The process of developing a plan for an
improved system, based on the result of the systems
analysis
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System Development Life Cycle (SDLC)
SDLC is an organized set of activities that guides
those involved through the design, development,
and implementation of an information system.
The number and names of each SDLC phase
may vary by author and software company, but
they all are very similar.
For this class, we will use the phases shown in
this presentation.
The participants include technical staff, but also
include non-technical business experts including
end-users.
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Users
Users are individuals that use a system
to perform their jobs.
Users provide insight to the day-to-day
business operations.
Users must be included from the
beginning to the end so that they will
feel some sense of ownership of the
new system when it is implemented.
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Who Participates?
Project
Team
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Systems Analyst: A Change Agent
Systems analyst functions as the change agent.
The catalyst or persuader who overcomes the
reluctance to change within an organization
What it takes:
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Coordination of many people, tasks, and schedules
Communication skills, both oral and written
Planning and design (an analytical mind)
Self-discipline and self-direction
Good organizational skills
Creativity
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Systems Development Life Cycle
1. Preliminary Investigation
•Problem Definition
•Feasibility
5. Implementation
•Training
•Conversion
•Evaluation
•Maintenance
4. Development
•Scheduling
•Programming
•Testing
Ongoing Activities
•Project Management
•Feasibility Assessment
•Documentation
•Information Gathering.
2. Analysis
•Gather data
•Analyze data
•Develop requirements
3. Design
•Preliminary design
•Detail design
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Phase 1:
Preliminary Investigation
A brief study of the problem to determine
whether the project should be pursued
Usually launched by a formal project request.
Define the Problem
Set scope (boundaries) of the problem
One of the deliverables is the Feasibility
Assessment.
Feasibility - measure of how suitable the
development of a system will be to the
organization.
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Feasibility Assessment Report
Introduction – brief statement
Existing System
Background
 Problems

Benefits of a New System
Feasibility of a New System
Operational
 Schedule
 Technical
 Economic
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Recommendation
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Phase 2: Analysis
What is the definition of Analysis?

Studying an existing system to determine how
it works and how it meets user’s needs.
What needs to occur so an analyst can
determine how the current system works?
Gather and analyze data
 From these findings, the system requirements
for the new system can be determined.
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Data Gathering Techniques
Review current system documentation
Interview users and managers
Structured interview – includes only questions
that have been written out in advance
 Unstructured interview – interviewer has a
general goal but few, if any questions prepared
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Questionnaires
Observation
Many of the reports, diagrams, and
documentation are entered into the Project
Notebook, Dictionary, and/or Repository. 15
Data Analysis
During this stage the problem definition is refined.
A detailed list of system requirements is created
without regard to any specific hardware or
software
Typical tools to represent data and procedures:
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Entity Relationship Diagram (ERD)
Data Flow Diagram (DFD)
Decision table/Decision Tree
Report findings and recommendations to
management
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Systems Development Life Cycle - continued
1. Preliminary Investigation
•Problem Definition
•Feasibility
5. Implementation
•Training
•Conversion
•Evaluation
•Maintenance
4. Development
•Scheduling
•Programming
•Testing
Ongoing Activities
•Project Management
•Feasibility Assessment
•Documentation
•Information Gathering.
2. Analysis
•Gather data
•Analyze data
•Develop requirements
3. Design
•Preliminary design
•Detail design
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Phase 3: Design
The new system is actually planned
Divided into two sub-phases
 Preliminary design
High-level design
 Decide to Build or Buy
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Detail design specifications
Input and Output requirements
 Design databases
 Specific network and security needs
 Develop Disaster Recovery Plans
 May enter data into a CASE Tool to generate
drawings and actual programming code
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Computer Aided Software Engineering
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Build or Buy?
Build Software
 Customized
 Developed in-house
 Developed by outside
vendor
 Prototyping – limited
function if any; shows what
system may look like.

Will be proceeding to
Phase 4: Development
Buy Software
 Prepackaged software
 Select software vendor
 Customization may be
offered by software
vendor for a price

Will be proceeding to
Phase 4: Testing
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Phase 4: Development
Scheduling
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Define tasks and schedule
Use project management software to plan human
resources and dependencies (see next slide).
Programming
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Develop actual programs that make up the system
Each program is tested by the programmer.
Testing
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Use various tests to evaluate entire system
(Testing slide coming up…)
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Project Management
The process of planning, scheduling, and
controlling activities
Set scope (goal, objectives, expectations)
Activities and Deliverables to be completed
The order activities occur (some activities
are concurrent and others are dependent)
Gantt Chart
Time and cost estimates
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Testing Types
Perform testing with predefined test data.
Unit testing – verifies that individual
program units work.
System testing – determines whether all
program units work together as planned.
Volume testing – uses real data in large
amounts to see if system can handle it.
Load testing – used to determine if system
can handle large number of concurrent
users.
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Phase 5: Implementation
Training – hands-on and user manuals
Equipment conversion – allow for delivery and
installation
File conversion – manual to electronic, or system’s
old format to new format
Auditing - need to be able to track data in system
back to the source.
Evaluation – does system meet original
requirements, benefits, and budget?
Maintenance – Fix bugs, enhancements, and new
regulations
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System conversion (see next slide)
System Conversion Options
Direct conversion – the user simply stops using
the old system and starts using the new one
Parallel conversion – the old and new systems
are both used until users are satisfied the new
system works
Phased conversion – the system is
implemented one part at a time
Pilot conversion – the entire system is used
by a designated set of users
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Systems Development Life Cycle - end
1. Preliminary Investigation
•Problem Definition
•Feasibility
5. Implementation
•Training
•Conversion
•Evaluation
•Maintenance
4. Development
•Scheduling
•Programming
•Testing
Ongoing Activities
•Project Management
•Feasibility Assessment
•Documentation
•Information Gathering.
2. Analysis
•Gather data
•Analyze data
•Develop requirements
3. Design
•Preliminary design
•Detail design
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MCC Related Courses
CIS224 – Project Management
CIS225AB – Object-Oriented Systems
Analysis and Design
CIS250 – Management Information
Systems
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