Transcript MIS 301 - Technology & Management

MIS 385/MBA 664
Systems Implementation with DBMS/
Database Management
Dave Salisbury
[email protected] (email)
http://www.davesalisbury.com/ (web site)
Information Systems Architecture
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A conceptual
blueprint or plan
that expresses the
desired future
structure for the
information systems
in an organization.
Architecture example
Business
Operations
Customers
& Suppliers
External
Events
Integrated
data warehouse
CIM
EDI
External
database
access
Data
validation
and
retention
Access
analysis &
presentation
Tools
Information
delivery system
Decision makers
Customers, Suppliers
A more sophisticated example...
Information Systems Architecture
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Key Components:
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data
processes which manipulate data
network which transports data
people who perform processes and send and
receive data
events and points in time when processes are
performed
reasons for events and rules which govern data
processing
Information Engineering
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An Information
Systems
Architecture is
developed by IS
planners following a
particular
methodology such
as Information
Engineering.
Information Engineering
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Data-oriented methodology
Uses top-down planning in which specific
information systems are deduced from a
broad understanding of organization’s
information needs, rather than relying on
specific user information requests
Offers perspective on relationship of
information systems to business objectives
Top-Down vs. Bottom-Up
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Top-Down Planning:
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A methodology that
attempts to gain a
broad understanding
of the information
system needs of the
entire organization
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Bottom-Up Planning:
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A methodology that
identifies and defines
IS development
projects based upon
solving operational
business problems or
taking advantage of
business
opportunities
Information engineering
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Information systems planning
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Identify strategic planning factors (goals, CSFs,
problem areas)
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Identify corporate planning objectives
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IT vision
Information system architecture
Develop enterprise model
Systems analysis
Systems design
Implementation
Systems Development Life Cycle
Project Identification & Selection
Project Initiation & Planning
Analysis
Logical Design
Physical Design
Implementation
Maintenance
Database SDLC
SDLC
Database Development
Activities
Identify Project
Initiate and Plan
Analyze
Logical Design
Physical Design
Implementation
Maintenance
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation
DB
Implementation
DB
Maintenance
Planning Matrixes
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Show interrelationships between
objects.
Location-to-Function
 Unit-to-Function
 Information System-to-Data Entity
 Supporting Function-to-Data Entity
 Information System-to-Objective
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Business Function-to-Data Entity
Planning Matrix
Information System-to-Objective
Planning Matrix
Functional Decomposition
Enterprise Data Modeling
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The first step in
database
development, in
which the scope and
general contents of
organizational
databases are
specified.
Enterprise Data Model
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A model which includes:
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overall range of organizational
databases
general contents of organizational
databases
Built as part of IS planning for the
organization and not the design
of a particular database
One part of an organization’s
overall information systems
architecture (ISA)
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation
DB
Implementation
DB
Maintenance
Conceptual Database Modeling
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Determine user
requirements
Determine business
rules
Build conceptual data
model
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outcome is an entityrelationship diagram or
similar communication
tool
population of repository
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation
DB
Implementation
DB
Maintenance
Logical Database Design
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Select logical database
model
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commit to a database
alternative
Map Entity-Relationship
Diagrams
Normalize data
structures
Specify business rules
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation
DB
Implementation
DB
Maintenance
Physical Database Design
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Select DBMS
Select storage devices
Determine access
methods
Design files and indexes
Determine database
distribution
Specify update
strategies
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation
DB
Implementation
DB
Maintenance
Database implementation
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Code and test
database processing
programs
Complete
documentation
Install database and
convert data
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation
DB
Implementation
DB
Maintenance
Database Maintenance
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Analyze database and
applications to ensure
evolving information
requirements are being
met
Tune database for
improved performance
Fix errors
Provide data recovery
when needed
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation
DB
Implementation
DB
Maintenance
Documentation
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most formal development methodologies are
documentation based
helps managers monitor progress and quality
of project
facilitates communication between team
members
includes models
various stages are not complete until
documentation is accepted
Some Keys to Success...
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accurate requirements definition
commitment
effective change management
manageable size
champion
Three Schema Architecture for
Database Development
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Conceptual Schema
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External Schema
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Analysis project phase
Analysis and Logical Design phases
(subset of conceptual schema)
Internal Schema
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Physical Design phase
3-schema architecture
Conceptual Schema
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Describes the logical structure of the
entire database
Independent of a specific DBMS
Avoids details of physical design
Stated in
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ERDs
metadata
External Schema
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Also called a user view
Specifications include screen formats,
report formats, transaction definitions
Physical Schema
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Describes physical structure of entire
database
Specifies how data from a conceptual schema
are stored in secondary memory
Sometimes called internal schema
Specifications include physical file and data
structures, storage organization, and index
structures
3-schema development process
Rapid application development (RAD)
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design methodology which speeds systems
delivery through a combination of speedy
design iterations, data modeling,
user/developer teamwork, and automated
development tools.
encompasses a set of techniques that can be
used to build complex, strategic, and missioncritical applications in months rather than
years
RAD
The RAD lifecycle
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requirements planning
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design
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conduct JAD workshop
construction
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conduct joint requirement planning workshop
members of team monitor evolution, system is
prototyped
cutover
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installation
Within the time box...
Requirements
planning
User design
construction phase
Build &
evolve prototype
User review
request for change
Evaluate
system
cutover
time box
Barriers to overcome...
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poor training/ tools
reluctance to leave old methods behind
mindset that RAD is not adequate for
large-scale systems development
speedy delivery does not mean low
quality
“scope/function creep”
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