Steps, Tools, and Techniques Chapter 6 Systems Development

Transcription

Steps, Tools, and Techniques Chapter 6 Systems Development
Chapter 6
Systems Development
Steps, Tools, and
Techniques
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Presentation Overview
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Seven Phases In The Systems
Development Life Cycle
Knowledge Workers and Their Roles In
The Systems Development Life Cycle
Why Systems Fail
Selfsourcing
Outsourcing
Prototyping
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Introduction

Systems development
life cycle (SDLC) - a
structured step-by-step
approach for developing
information systems.
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Lets bake a cake
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Seven Phases in the SDLC
Phase 1: Plan
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Planning phase - involves determining
a solid plan for developing your
information system.
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Critical success factor (CSF) - a factor
simply critical to your organization’s
success.
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Seven Phases in the SDLC
Phase 1: Plan
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Project scope – high-level system requirements.
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Project scope document – written project scope
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Project plan – defines the what, when, and who
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Project milestones - key dates for deliverables.
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Project manager - an expert in project planning.
definition.
questions.
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Seven Phases in the SDLC
Phase 2: Analysis
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Analysis phase - involves end users and IT
specialists working together to gather,
understand, and document the business
requirements for the proposed system.
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Business requirements - the detailed set of
knowledge worker requests that the system must
meet in order to be successful.
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Seven Phases in the SDLC
Phase 2: Analysis
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Joint application development (JAD) - knowledge
workers and IT specialists meet, sometimes for several
days, to define or review the business requirements for
the system.
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Requirements definition document – prioritizes the
business requirements and places them in a formal
comprehensive document.
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Sign-off - the knowledge workers’ actual signatures
indicating they approve all of the business requirements.
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Seven Phases in the SDLC
Phase 3: Design
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Design phase - build a technical blueprint
of how the proposed system will work.
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Technical architecture - defines the hardware,
software, and telecommunications equipment
required to run the system.
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Seven Phases in the SDLC
Phase 3: Design
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Modeling - the activity of drawing a
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Graphical user interface (GUI) - the
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GUI screen design - the ability to model
graphical representation of a design.
interface to an information system.
the information system screens for an
entire system.
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Seven Phases in the SDLC
Phase 3: Design
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Seven Phases in the SDLC
Phase 4: Development
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Development phase - take all of your
detailed design documents from the
design phase and transform them into
an actual system.
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Seven Phases in the SDLC
Phase 5: Test
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Testing phase - verifies that the
system works and meets all of the
business requirements defined in the
analysis phase.
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Test conditions - the detailed steps the
system must perform along with the
expected results of each step.
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Seven Phases in the SDLC
Phase 6: Implement
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Implementation phase - distribute the system
to all of the knowledge workers for use.
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User documentation - how to use the system.
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Online training - runs over the Internet or off a CD-
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Workshop training - is held in a classroom
ROM.
environment and lead by an instructor.
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Seven Phases in the SDLC
Phase 7: Maintain
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Maintenance phase - monitor and
support the new system to ensure it
continues to meet the business goals.
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Help desk - a group of people who
responds to knowledge workers’ questions.
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Knowledge Workers and Their
Roles in the SDLC
Your participation in the systems
development process is vitally important
because you are (or will be) a:
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1.
2.
3.
4.
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Business process expert
Liaison to the customer
Quality control analyst
Manager of other people
User acceptance testing (UAT) –
determines if the system satisfies the
business requirements.
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Why Systems Fail
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20% of systems are successful, 80% of
systems fail.
Five primary reasons why systems fail include:
1.
2.
3.
Unclear or missing requirements
Skipping SDLC phases
Failure to manage project scope
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4.
5.
Scope creep – project scope increases
Feature creep – developers add extra features
Failure to manage project plan
Changing technology
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Insourcing
Three choices for building a system include:
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1.
2.
3.
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IT specialists within your organization - Insourcing
Knowledge workers such as yourself – Selfsourcing
Another organization – Outsourcing
Insourcing - IT specialists within your
organization will develop the system.
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Selfsourcing
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Selfsourcing (also called
knowledge worker
development or end
user development) - the
development and support
of IT systems by
knowledge workers with
little or no help from IT
specialists.
On Your Own
How Have
You Selfsourced?
(p. 303)
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Selfsourcing
The Selfsourcing Process
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Selfsourcing
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Advantages:
 Improves requirements determination.
 Increases knowledge worker participation and ownership.
 Increases speed of systems development.
Disadvantages:
 Inadequate knowledge worker expertise leads to
inadequately developed systems.
 Lack of organizational focus creates “privatized” IT
systems.
 Insufficient analysis of design alternatives leads to subpar
IT systems.
 Lack of documentation and external support leads to
short-lived systems.
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Outsourcing
Developing Strategic Partnerships
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Outsourcing - the
delegation of
specific work to a
third party for a
specified length of
time, at a specified
cost, and at a
specified level of
service.
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Outsourcing
The Outsourcing Process
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Outsourcing
The Outsourcing Process
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Request for proposal (RFP) - a formal
document that describes in detail your logical
requirements for a proposed system and invites
outsourcing organizations to submit bids for its
development.
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Outsourcing
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Advantages:
 Focus on unique core competencies.
 Exploit the intellect of another organization.
 Better predict future costs.
 Acquire leading-edge technology.
 Reduce costs.
 Improve performance accountability.
Disadvantages:
 Reduces technical know-how for future innovation.
 Reduces degree of control.
 Increases vulnerability of strategic information.
 Increases dependency on other organizations.
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Prototyping
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Prototyping - the process of building a model that
demonstrates the features of a proposed product,
service, or system.
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Prototype - a model of a proposed product, service, or system.
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Proof-of-concept prototype - used to prove the technical
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Selling prototype - used to convince people of the worth of a
feasibility of a proposed system.
proposed system.
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Prototyping
The Prototyping Process
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Prototyping
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Advantages:
 Encourages participation.
 Resolves discrepancies
 Gives a feel for the final system.
 Helps determine technical feasibility.
 Helps sell the idea of a proposed system.
Disadvantages:
 Leads to the belief that the final system will follow
shortly.
 Gives no performance indication.
 Leads the team to skip testing and documentation.
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