Post on 17-Aug-2021
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Jon McBee
Senior Project Engineer
LabVIEW Champion
Bloomy
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How to Eat the Elephant
Turning Ideas Into Architecture
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Overview
• Introduction
• What is Architecture
• How do you communicate
• UML
• Sketches
• Example
• Questions
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Background Information
• Bloomy Quick Facts • 22 year NI Alliance Partner - Platinum level
• Products, platforms, and custom systems for ATE, DAQ, and Control
• NI Electronic Design Specialty, Vision Specialty, and Embedded Control Specialty
• 19 NI Certified LabVIEW Architects
• 3 NI Certified Training Centers
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Introduction
• A new project comes in, where do you start?
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Typical Software Lifecycle
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Requirements
Gathering Design Development
Debugging &
Testing Deployment Architecture
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What is Architecture?
“A good architecture avoids complicated systems by building them out of lots of simple components whose interactions can certainly create a complex system but not one that needs to be overly complicated” -Peter Cripps
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“The high level structure of a system, the discipline of creating such a high level structure, and the documentation of this structure” -Wikipedia
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Architecture Components
• Software Model • Defines how components interact at different levels of
abstraction
• Diagrams/Sketches
• What we are building
• Software Design • Structure of the software system
• Design Patterns/SDK/API/Data Structures
• How we are building
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Software Models
• A visual representation of a software application • Defines how components interact
• Comprised of multiple views at different levels of abstraction
• Context Sketch
• Container Sketch
• Component Sketch
• UML Model
• Target Audience • Who will use these models?
• Everyone must understand model paradigm
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Who Uses UML on a Regular Basis?
• Unified Modeling Language • General purpose modeling language
• Provides standard way to visualize system design
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What UML Diagrams do you Use?
• Behavioral • Activity
• Sequence
• State
• Structural • Class
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Why Don’t you use UML?
• I don’t know it • My team doesn’t know it
• My customers don’t know it
• I don’t need it • There is too much there/High barrier to entry
• My software is simple
• We don’t use object-oriented programming/design
• I don’t have it • I don’t have a tool
• Other reasons? • LabVIEW is self documenting…
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How do you communicate?
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• Unexplained definition of diagram elements like the styles of boxes and lines
• Missing or ambiguous relationships between diagram elements
• Omission of technology choices (or options)
• Mixing different levels of abstraction.
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LowUML
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• Many stakeholders do not have an understanding of UML, and this makes UML a difficult tool to use at higher levels of abstraction
• Using a simpler notation makes it easier to communicate the architecture • Using well defined levels of abstraction allows us to target different stakeholder
perspectives
When we reach the lower levels of abstraction, closer to design, a simple notation may not be sufficient and it is at this point we can switch to using a notation such as UML which can help describe complex designs.
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System Context
• High-Level Diagram • What are we building?
• Who is using it?
• How does it work with existing infrastructure?
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System
Actor
Actor
Existing System
Existing System
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System Context
• Makes the context explicit, minimizing assumptions
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System
Actor
Actor
Existing System
Existing System
System X? System
X
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System Context
• Helps identify who you need to talk to regarding which pieces of the system
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System
Actor
Actor
Existing System
Existing System
System X Tom
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System Context
• Doesn’t show much detail • Acts as a starting point for other diagrams
• Acts as a starting point for conversations
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System
Actor
Actor
Existing System
Existing System
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Containers
• Multiple containers make up a context • High-level technology decisions
• Overall shape of the system
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System
Container
Container
Container
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Containers
• Each container has a • Name
• (Technology)
• Responsibility
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DB
SPC UI (HTML)
• Display
SPC Charts
• Can select by UUT
DB Query Engine
(LabVIEW)
• Structures SPC data
• Queries DB
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Containers
• Illustrates • Purpose of interaction
• (Communication method) • Protocols
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DB
SPC UI (HTML)
• Display
SPC Charts
• Can select by UUT
DB Query Engine
(LabVIEW)
• Structures SPC data
• Queries DB
Requests Data (Web Service) • HTTP
Returns Data (Web Service) • HTTP
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Containers
• Can show interaction of containers with actors external to context
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DB
SPC UI (HTML)
• Display
SPC Charts
• Can select by UUT
DB Query Engine
(LabVIEW)
• Structures SPC data
• Queries DB
Requests Data (Web Service) • HTTP
Returns Data (Web Service) • HTTP
Manufacturing Engineer
QA Engineer
Tracks production by
station
Tracks failures by part
Queries DB (SQL) • TCP
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Containers
• Frames question: “Where do I need to write code in order implement features?”
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DB
SPC UI (HTML)
• Display
SPC Charts
• Can select by UUT
DB Query Engine
(LabVIEW)
• Structures SPC data
• Queries DB
Requests Data (Web Service) • HTTP
Returns Data (Web Service) • HTTP
Manufacturing Engineer
QA Engineer
Tracks production by
station
Tracks failures by part
Queries DB (SQL) • TCP
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Components
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System
Container
Container
Container
Component Component
• Building blocks of system
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Components
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Web Service (Actor)
• Called by Web Resource methods
DB Interface (Actor)
• Queries database
• Each Component has a • Name • (Technology) • Responsibility
SPC UI DB
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Components
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Web Service (Actor)
• Called by Web Resource methods
DB Interface (Actor)
• Queries database
• Illustrates • Interaction • Communication Method • Protocols
SPC UI DB Class based messaging (Actor Framework)
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Components
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Web Service (Actor)
• Called by Web Resource methods
DB Interface (Actor)
• Queries database
• Should map to requirements • Use Cases • User Stories • Feature Request
SPC UI DB Class based messaging (Actor Framework)
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UML
• Use where necessary
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System
Container
Container
Container
Component Component
UML UML UML UML
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UML
• UML fits well at this lower level of abstraction
• UML may fit at higher levels • Sequence diagram of component interaction within a container
• Sketches focus on structure, UML can inject processes and detailed behavior when needed
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Define Your Notation
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Symbols Colors
Context
Container
Component
Data
Actor
Internal
External
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Ex. System Context
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Customer
• Check Balance • Deposit • Withdraw • Transfer
Enterprise Database
Physical Console
• Retrieve Account • Update Account
• Button Press • Debit Card • Display Info
Automatic Teller Machine Simulator
Enterprise Database
Physical Console
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Ex. Containers
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Simulation Interface (LabVIEW)
• Program run to test ATM algorithms
Account Database (Text File) • Interface by which the ATM
accesses and changes account information
ATM Message Table (Text File) • Table of message names and
message text displayed on console
ATM Error Log (Text File) • Error Log file which can be
checked by ATM maintenance personnel
Reads from and writes to
Reads from and writes to
Reads from and writes to
ATM Simulator
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Ex. Components/Modules
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Uses Uses Uses
Simulation Interface
Simulation Interface (Actor)
• Run to test ATM algorithms
Simulated Database (Actor)
• Mimics access to an Enterprise Database
ATM Controller (Actor)
• Manages users, accounts, and transactions
Simulated Console (Actor)
• Mimics physical console
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How to eat the elephant
• Understand how your stakeholders see the elephant
• Use sketches to establish structure at different levels of abstraction
• Use sketches to communicate with stakeholders • Both external and internal
• Use UML where and how it most benefits your design • LowUML
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Further Reading
• http://www.codingthearchitecture.com/
• http://www.umlzone.com/articles/agile-software-architecture-and-nouml/
• http://softwarearchitecturezen.blogspot.com/2011/05/sketching-with-uml.html
• http://martinfowler.com/articles/designDead.html
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Questions?
• Please visit Expo Booth #305
• Check out the new: www.bloomy.com
• Email: info@bloomy.com
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Sketches...
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• Help everybody understand the “big picture” of what is being built
• Create shared vision of what you’re building within the development team
• Provide a point of focus for those technical conversations about how new features
should be implemented
• Provide a map that can be used by software developers to navigate the source
code
• Help people understand how what they are building fits into the “bigger picture”
• Help you to explain what you’re building to people outside of the development
team (e.g. operations and support staff, non-technical stakeholders, etc)
• Fast-track the on-boarding of new software developers to the team
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What UML Diagrams do you Use?
• Class Diagrams • The top part contains the name of the class
• The middle part contains the attributes of the class
• The bottom part gives the methods or operations the class can take or undertake
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• Relationships • Association
• Composition
• Aggregation
• Inheritance
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What UML Diagrams do you Use?
• Sequence Diagram • Messages, written with
horizontal arrows with the message name written above them, display interaction.
• Solid arrow heads represent synchronous calls
• Open arrow heads represent asynchronous messages
• Dashed lines represent reply messages
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What UML Diagrams do you Use?
• State Machine Diagram • Filled circle, pointing to the initial
state
• Hollow circle containing a smaller filled circle, indicating the final state (if any)
• Rounded rectangle, denoting a state. Top of the rectangle contains a name of the state. Can contain a horizontal line in the middle, below which the activities that are done in that state are indicated
• Arrow, denoting transition. The name of the event (if any) causing this transition labels the arrow body.
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What UML Diagrams do you Use?
• Activity Diagram • Rounded rectangles represent actions
• Diamonds represent decisions
• Bars represent the start (split) or end (join) of concurrent activities
• A black circle represents the start (initial state) of the workflow
• An encircled black circle represents the end (final state)
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State vs. Activity
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State Machine Diagram Activity Diagram