-
?
介绍几种系统设计策略
?
描述一个信息系统开发项目中设计阶段的任务
Systems design
–
the specification of a
detailed computer-based solution.
?
Also called
physical design
.
?
systems
analysis emphasizes the business problem
?
systems
design
emphasizes
the
technical
or
implementation
concerns
of
the
system.
System Design
Approaches
?
Model-Driven
?
Modern structured design
?
Information
engineering
?
Prototyping
?
Object-oriented
?
RAD
Object-
oriented design (OOD)
techniques are
used to refine the object requirements definitions
identified earlier during analysis, and
to define design specific objects.
?
对象技术试图消除“数据”和“过程”内容的分离
Rapid
application
development
(RAD)
–
反复使用结构化技术和原型化技术
来定义用户的需
求并设计最终系统。
模型
-
原型
-
模型
-
原型?
最总得出一个组合的业务需求和技
术设计陈述，它们用以构造新系统
System Design Tasks For In-House
Development (Build)
?
Design the Application Architecture
?
Define
technologies
to
be
used
by
(and
used
to
build)
one,
more,
or
all
information systems.
?
Revise
（修改）
models as physical models
?
Design the
System Databases
?
Database schema
?
Optimized for implementation DBMS
?
Design the
System Interface
?
Input, output, and dialogue
specifications
?
Prototypes
?
Package Design Specifications
?
Specifications
to guide programmers
?
Update Project Plan
Physical
data
flow
diagram
(DFDs)
–
a
process
model
used
to
communicate
the
technical
implementation
characteristics of an information system.
?
Communicate
technical
choices
and
other
design
decisions
to
those
who
will
actually construct and implement the
system.