CHAPTER 10 SYSTEM ENGINEERING

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CHAPTER 10SYSTEM ENGINEERING

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Outline

• Overview
• Systems
• System engineering hierarchy
• Business process engineering
• Product engineering
• Requirements engineering
• System modeling

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Overview

• WHAT To understand the system
• Determine the overall objective
• Identify the system elements role
• Create operational requirements
• WHO System engineer
• Work with the customer, future users, and other
  stakeholders
• WHY To fit the system

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Overview(cont.)

• PRODUCT Effective representation
• Prototype
• Specification
• Symbolic model

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Systems

• Software-centric
• Hierarchy
• Top-down
• Button-up
• Complex system
• A system

• A macro-element of bigger system

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Computer-based systems

• Software
• Hardware
• People
• Database
• Documentation
• Procedures

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System engineering hierarchy
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System modeling

• Define the processes that serve the needs of the
  view under consideration
• Represent the behavior of the processes and the
  assumptions on which the behavior is based
• Explicitly define the exogenous and endogenous
  input to the model
• Represent all linkages (including output) that
  will enable the engineer to better understand the
  view

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System modeling restraining factors

• Assumptions
• Simplifications
• Limitations
• Constraints
• Preferences

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System simulation

• Reactive system
• Test with unreal actor

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Business process engineering
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Business process engineering (cont.)

• BPE architecture
• Data architecture
• Applications architecture
• Technology infrastructure

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Product engineering
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Requirements engineering

• Requirements elicitation
• To know what the customer wants
• Why hard?
• Problems of scope
• Problems of understanding
• Problems of volatility
• Steps
• Product

• A statement of need and feasibility
• A bounded statement of scope
• A list of customers, users, and other
  stakeholders
• A description of systems technical environment
• A list of requirements and constraints
• A set of usage scenarios
• Prototypes

• Define the technical environment
• Identify domain constraints
• Solicit participation from many people
• Identify ambiguous requirements
• Create usage scenarios

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Requirements engineering (cont.)

• Requirements analysis and negotiation
• Analysis
• Consistent?
• Proper?
• Necessary?
• Bounded and unambiguous?
• Attribution?
• Achievable?
• Testable?
• Negotiation

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Requirements engineering (cont.)

• Requirements specification
• Any type
• System modeling
• Take a look
• Requirements validation
• ?
• Requirements management
• Traceability table

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Traceability table

• Feature traceability table
• Source traceability table
• Dependency traceability table
• Subsystem traceability table
• Interface traceability table

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System modeling

• System modeling template

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System modeling (cont.)

• System context diagram

Main system
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System modeling

• System flow diagram

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Summary

• Analysis system from top to down, from large to
  tiny
• Look from variant direction
• Make everything clear before do it
• Leave documentation