Workshop: SADT: Structured Analysis & Design Technique
SADT — Structured Analysis & Design
Technique
Yuling Li
12/5/16
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Workshop: SADT: Structured Analysis & Design Technique
How to Make a Pizza?
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Workshop: SADT: Structured Analysis & Design Technique
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Workshop: SADT: Structured Analysis & Design Technique
How to Make a Pizza (Process/Activities) Systematically?
• Analysis Determine what the system will do
• Design Define subsystems and their interfaces
• Implementation Create the subsystem independently
• Integration Combine the subsystems into a single unit
• Testing Verify the system workings
• Installation Make the system operational
• Operation Use the system
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Workshop: SADT: Structured Analysis & Design Technique
“M models A if M answers questions about A”
---- Douglas T. Ross
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Workshop: SADT: Structured Analysis & Design Technique
Contents
1 Overview of SADT
2 Syntax and Semantics
3 SADT Diagrams
4 Cases
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Workshop: SADT: Structured Analysis & Design Technique
1 Overview of SADT
SADT
IDEF0
IDEF Family
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Workshop: SADT: Structured Analysis & Design Technique
Emergent
1950s “hierarchic, layered modular system” SA
Box
1960s “system of systems for building systems” SA
Decomposition
“top-down hierarchic decomposition”
➕
“Hori’s Human-directed activity cell model” Cell
1970s
modelling
“language for blueprinting systems”
SADT
• Douglas T. Ross developed SADT (1969-1973 )
• SADT is a trademark of SofTech, Inc. (After 1973)
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Workshop: SADT: Structured Analysis & Design Technique
Develop
• During the 1970s, the U.S. Air Force Program for Integrated Computer
Aided Manufacturing(ICAM) sought to increase manufacturing
productivity through systematic application of computer technology.
1970s government (US Department of Defense) version IDEF0 introduced
1980s “under the name of IDEF0, SADT has been used in military and industrial organisations”
1990s renamed in 1999 as Integration DEFinition
IDEF family of methods
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Workshop: SADT: Structured Analysis & Design Technique
IDEF Family
§ IDEF0 : Function modeling
§ IDEF1 : Information modeling
§ IDEF1X : Data modeling
§ IDEF2 : Simulation model design
§ IDEF3 : Process description capture
§ IDEF4 : Object-oriented design
§ IDEF5 : Ontology description capture
§ IDEF6 : Design rationale capture
§ IDEF7 : Information system auditing
§ IDEF8 : User interface modeling
§ IDEF9 : Business constraint discovery
§ IDEF10 : Implementation architecture modeling
§ IDEF11 : Information artifact modeling
§ IDEF12 : Organization modeling
§ IDEF13 : Three schema mapping design
§ IDEF14 : Network design
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Workshop: SADT: Structured Analysis & Design Technique
SADT Structured Analysis and Design Technique
Structured Analysis and Design Technique, is a graphical language for describing
systems together with a methodology for producing such descriptions.
An SADT model contains a set of diagrams that describe a system from an
identified viewpoint and for a particular purpose.
SADT as a language and as a methodology directs and disciplines the analysis and
design of systems. (Dickover, 1977)
Structured Analysis and Design Technique, is a graphical notation and an approach
to system description. (David A. Marca, 1988)
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Workshop: SADT: Structured Analysis & Design Technique
Model
IDEF0 models comprising system functions (actions, processes,
operations), functional relationships, and the data and objects
that support systems analysis and design, enterprise analysis, and
business process re-engineering.
Integrated Computer-Aided Manufacturing (ICAM) Function Modeling
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Workshop: SADT: Structured Analysis & Design Technique
2 Syntax and Semantics
q Syntax
• The structure components and features of language and the rules that define
relationships among them.
• Boxes represent functions, defined as activities, processes or transformations.
• Arrows represent data or objects related to functions.
q Semantics
• Semantics refers to the meaning of syntactic components of a language and
aids correctness of interpretation.
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Workshop: SADT: Structured Analysis & Design Technique
Boxes and Arrows
Fig. Box and Arrow Syntax (Standard, 1993)
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Workshop: SADT: Structured Analysis & Design Technique
Box and Arrow Semantics
—— SA box
The things that constrains
activities
e.g. laws, regulations
CONTROL
INPUT SUBJECT OUTPUT
Those things used and Result of activity
transformed by activities e.g. products, service
e.g. raw materials, data
MECHANISM
Things which carry out the activity
e.g. storage places, people,
organisations, devices
Under control, input is transformed or consumed into output by the mechanism.
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Workshop: SADT: Structured Analysis & Design Technique
Labels and Names
§ A function name shall be an active verb or verb phrase, such as:
process parts, plan resources, conduct review, monitor performance,
design system provide maintenance, develop detail design, fabricate
component, inspect part…
§ The arrows shall be labeled with a noun or noun phrase, such as:
specifications, test report, budget, design requirements, detail design,
directive, design engineer, board assembly, requirements…
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Workshop: SADT: Structured Analysis & Design Technique
Example
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Workshop: SADT: Structured Analysis & Design Technique
3 SADT Diagrams
Types of Diagram
Diagram Features
Diagram Syntax Rules
Diagram Reference Expressions
Models
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Workshop: SADT: Structured Analysis & Design Technique
v Type of Diagram
Top-Level Context Diagram
§ Subject of model represented by single box with bounding arrows.
§ Called A-0 (“A minus zero”)
§ Box and arrows are very general
§ Sets model scope or boundary and orientation.
§ Should include
– Purpose
– Viewpoint
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Workshop: SADT: Structured Analysis & Design Technique
Example
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Workshop: SADT: Structured Analysis & Design Technique
Child Diagram
§ Single process in Context Diagram (A-0) may be decomposed into
sub-processes and modeled in a child (A0) diagram.
§ Each process in the A0 diagram may be decomposed further into
sub-processes and modeled in (grand-) child (A1, A2, … A6)
diagrams.
§ Each (grand-) child process may be decomposed further into sub-
processes and modeling (great-grand-) child diagrams.
Parent Diagram
§ A parent diagram is one that contains one or more parent box.
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Workshop: SADT: Structured Analysis & Design Technique
Parent
Child
Parent
Child Parent
Child
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Workshop: SADT: Structured Analysis & Design Technique
v Diagram Features
Concurrent Operation
Arrow as Constraints
Arrow as Pipelines
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Workshop: SADT: Structured Analysis & Design Technique
Arrow Between Boxes
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Workshop: SADT: Structured Analysis & Design Technique
Boundary Arrows and Coding
• Boundary arrows on an ordinary
graphic diagram represent the inputs,
controls, outputs, or mechanisms of
the diagram’s parent box.
• All boundary arrows on a child
diagram (except for tunneled arrows)
shall correspond to the arrows that
connect to its parent box.
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Workshop: SADT: Structured Analysis & Design Technique
Tunneled Arrows
• Provide information at a
specific level of
decomposition that is not
required for understanding at
some other levels
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Workshop: SADT: Structured Analysis & Design Technique
v Diagram Syntax Rules
Ø Diagrams have boxes and arrows
Ø Box represent activities
Ø Boxes have dominance
Ø Arrows represent things
Ø Arrows represent interconnections among boxes
Ø Arrows are collections of things: branches and joins
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Workshop: SADT: Structured Analysis & Design Technique
v Diagram Reference Expressions
Fig. Negative Node-Numbered Context (Standard, 1993)
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Workshop: SADT: Structured Analysis & Design Technique
Example
A0 Manufacture Product
A1 Plan For Manufacture
A11 Identify Manufacturing Methods
A12 Estimate Requirements, Time, Cost to Produce
A13 Develop Production Plans
A14 Develop Support Activities Plan
A2 Make and Administer Schedules and Budgets
A21 Develop Master Schedule
A22 Develop Coordinating Schedule
A23 Estimate Costs & Make Budgets
A24 Monitor Performance To Schedule & Budget
A3 Plan Production
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Workshop: SADT: Structured Analysis & Design Technique
v Models
Ø A model answers questions
Ø A model has a single subject
Ø A model has one viewpoint
Ø Models are coordinated sets of diagrams
Ø A system is represented by a single box
Ø Identifying decompositions with node numbers
Ø Linking decomposition with C-number
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Workshop: SADT: Structured Analysis & Design Technique
Deposition
“M is a model of S if M can be used to answer questions about S with an accuracy of A”
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Workshop: SADT: Structured Analysis & Design Technique
Different Viewpoints
Fig. Two interconnected models of from different viewpoints. (Dickover, 1977)
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Workshop: SADT: Structured Analysis & Design Technique
Call Notation
• A call arrow is a special arrow of mechanism;;
• The caller box does not have its own child diagram to detail it;;
• But rather is detailed by another box in the same or another model;;
• Multiple caller boxes may call the same box.
CONTROL
INPUT SUBJET OUTPUT
MECHANISM CALL
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Workshop: SADT: Structured Analysis & Design Technique
Example
The decomposition of Model X is continued in Model Y;; Model Y ”support” model X
Situation1: Model X calling Situation2: a box in Model
Model Y X calling a box in Model Y
Fig. The call notation. (Dickover, 1977)
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Workshop: SADT: Structured Analysis & Design Technique
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