1. Software Systems Engineering
5/9/2019
Software Systems Engineering
Dr. M.E. Fayad, Professor
Computer Engineering Department, Room #283I
College of Engineering
San José State University
One Washington Square
San José, CA
5/9/2019 Fayad
SJSU -- CmpE

2. Lecture 1: Introduction2
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SJSU -- CmpE M.E. Fayad

3. 3 Lesson Objectives Discuss the following terms: Standards
Methodology/paradigm/process Models
Methods
processes
Discuss the essential properties of a process
Explore Process Models 3
5/9/2019
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SJSU -- CmpE M.E. Fayad

4. Standards
Standards imply regulations, guidelines, rules, laws, and so on.
Standards can dictate named methodologies, such as IEEE standards or DOD standards (Ex: DOD-STD-2167A).
A standard alone is not sufficient on getting a task completed. Why? 4
[Fayad-Laitinen 1998]
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SJSU -- CmpE M.E. Fayad

5. Standards
Because standards focus on the attributes of the results instead of how the results will be achieved
A standard also includes a type, model, or example commonly or generally accepted or adhered to, such a criterion set for usage or practices (moral standards)
Standards applies to some measure, principle, model, and so on, with which things of the same class are compared to determine their quantity, value, quality, and so forth (standards of purity in drugs) 5
[Fayad-Laitinen 1998]
5/9/2019 Fayad
SJSU -- CmpE M.E. Fayad

6. Methodology
A methodology is “a science of method or orderly arrangement” Webster.
A methodology is used to refer to the very highest level of the way we do things.
A methodology also refers to “a system of methods, as in particular science”
The methodology we will consider here cover only the development of software applications. 6
[Fayad-Laitinen 1998]
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SJSU -- CmpE M.E. Fayad

7. Methods or Techniques
A method implies a regular, orderly, logical procedure for doing something, such as a method of finding software requirements.
Exs: Waterfall model, spiral model [Boehm84], and fountain model [Henderson-Selers90].
Jacobson defines a method as a planned procedure by which a specific goal is approached step by step [Jacobson92].
Examples of software design method are a set of work procedures, a set of notations, or a set of heuristics. 7
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8. Methods or Techniques
Software engineering methods can be divided into three major categories:
1. Process-Oriented Methods [Yourdon89]
2. Data-Oriented Methods [Martin90]
3. Object-Oriented Methods [Fayad93, Rumnaugh91, etc..] 8
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9. POM vs. OOM 9
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10. Method Provides Foundation for Software Engineering10
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11. The Myth of the Single Software Development Method11
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12. How Many OO Methods Exist?
UML 12
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13. Engineering Process Hierarchy
Scientific Area
Standards
Methodologies
(Macrodevelopment Processes)
Techniques (Methods)
(Minidevelopment Processes)
Processes
(Microdevelopment Processes
Computer
Electronics
Hardware
Software
SASD
OOT
UML
OMT 13
Identify
Classes
Identify
Attributes
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14. Processes are Important for a new OO Teams
New methods and tools introduce confusion
Processes define exactly who, what, when, and how
“big-picture” 14
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15. Processes take OO methods out of the classroom and put them to work
Method vs. Process
Processes take OO methods out of the classroom and put them to work
Theoretical
Ideas
Predictions
Practical
Concrete Actions
Metrics 15
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SJSU -- CmpE M.E. Fayad

16. Software Engineering
Software engineering life cycles or phased software development models, such as
Waterfall model
Prototyping
Spiral Model
Automatic Programming
Reuse Models
Incremental Model
Fountain Model
XP Model
Software Stability Model 16
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17. 17 Waterfall Model Waterfall Model Requirements Analysis
Design
Coding
Specifications
Testing 17
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18. 18 Prototyping Requirements Specifications Requirements Analysis
Coding
Demonstration
Design
Testing
Maintenance
Prototype
Code
Test
Build
Document 18
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19. 19 Spiral Model [Boehm 87] SJSU -- CmpE M.E. Fayad Commitment
Partition
Cumulative Cost
Progress Through Steps
Determine
Objectives,
Alternatives,
Constraints
Review
Risk
Analysis
Prototype 2
Prototype 3
Anal.
Pt 1
Operational
Prototype
Simulations, Models, Benchmarks
Concept of
Operation
Software
Requirements
Validation
Product
Design
Design Validation
and Verification
Detailed
Code
Unit
Test
Acceptance
Imple-
mentation
Develop, Verify
Next-level
Plan Next Phases
Integration and
Test Plan
Development
Plan
Requirements Plan
Life-Cycle Plan
Evaluate Alternatives,
Identify, Resolve Risks
Integra-
tion
and Test
[Boehm 87] 19
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20. AUTOMATIC PROGRAMMING
5/9/2019
AUTOMATIC PROGRAMMING .
Requirements
Analysis
Formal
Specifications
Automatically
Generated Code
Developed by Dr. Goldberg and charged the Government 2 millions dollors to deliver a prototype. Nothing has been delivered.
This methodology has a major flaw in it.
+ You can not generate code from a specification (even with using a formal approaches)
+ What hapend to the design phase? 20
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21. 21 REUSABLE MODULES Decompose Application Domain Specify Module
5/9/2019
REUSABLE MODULES
Decompose
Application Domain
Specify Module
Requirements
Module Design
Module Code
Module Test
Application
Configure Reusable
Modules
Customize Reusable
Integrate Modules
Testing .
Reusable model fits very will with the OO Framework and we are going to show that in the later sections
Describe the model.
Talk about customization, Scaleability, and Tailorability. 21
OTI-93F-0014
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22. 5/9/2019
INCREMENTAL MODEL
Product
Design
Verification
Increment 3
Increment 2
Operations and
Maintenance
Revalidation
Detailed
Code
Unit Test
Integration
Implementation
System Test
Increment 1
System
Feasibility
Validation
Software Plans &
Reqmts .
“Analyze a little, design a little, and code a little” someone said that who? 22
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23. 23 FOUNTAIN MODEL Further Acceptance Development into Library Program
5/9/2019 .
FOUNTAIN MODEL
Further
Maintenance
Development
Acceptance
into Library
Program
Use
System
Further
Maintenance
Testing
Development
Testing
Coding
Coding
Design
Full development Method: Each activity start from the requirements analysis.
Reusable Model: Each activity start from the model specification.
So what do you mean
Module
Software
Design
Requirements
Specification 23
Requirements
Module
Analysis
Specification
[Henderson-Sellers90]
Real-World Systems
Real-World Entity
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24. Analysis & Design
What are the differences between requirement analysis and software design?
What are the requirement analysis and software design? 24
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25. 25 Analysis & Design Problem space Analysis One problem The “What”
Fuzzy line
Solution space
Design
Many solutions
The “How” 25
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SJSU -- CmpE M.E. Fayad

26. Discussion Questions
List all the major process activities in the lifecycle phases: Requirement analysis, software design, software construction, software testing, software maintenance
List all major activities in software project management: Software planning, Staffing, Controlling and tracking the project, etc.
T/F
Software processes should be fixed.
Software process should be measurable.
Software process specifies the why and ignore the how.
Define:
Automatic Programming and Fountain Model 26
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SJSU -- CmpE M.E. Fayad

27. Questions for the Next Lecture
The manager’s roles and responsibilities in software process
Measure process rather than people
The top five excuses for no process documentation
Process assessment
Process improvement models
The trouble with process assessment
How to use processes as a baseline for improvement
Software process hierarchy
How to document process
Recommendations for documenting processes 27
5/9/2019 Fayad
SJSU -- CmpE M.E. Fayad