1. Architectural Design of Distributed Business Systems
9/21/2018 7:05 PM
Architectural Design of Distributed Business Systems
Tutorial M3,
TOOLS Europe 2001
13 March 2001
Trygve Reenskaug
Mogul Norway AS, Oslo
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

2. The Autokon system for the Computer-Aided Design of Ships
Architectural Design of Distributed Business Systems
The Autokon system for the Computer-Aided Design of Ships
9/21/2018 7:05 PM
Architecture created
First deployed
First international
Converted to PC
Architecture still valid!!
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

3. The Autokon architecture Why the long life ?
Architectural Design of Distributed Business Systems
The Autokon architecture Why the long life ?
9/21/2018 7:05 PM
¤ Shipbuilding essentially unchanged
¤ Luck - random access mass storage
devices enabled database solution
¤ Reality reflected into
Clean, intelligible modular structure
¤ Expressed user needs as symptoms for required abstractions
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

4. The Autokon architecture Was it worth it ?
Architectural Design of Distributed Business Systems
The Autokon architecture Was it worth it ?
9/21/2018 7:05 PM
Y E S !
¤ System integrity maintained through major revisions
¤ System reliability maintained through
major revisions
¤ System is comprehensible to
users and maintainers
¤ Architecture spans decades of development projects
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

5. Exercise 1: What do WE mean by System Architecture?
Architectural Design of Distributed Business Systems
Exercise 1: What do WE mean by System Architecture?
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……………………………………….
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

6. Architectural Design of Distributed Business Systems
Highlights
9/21/2018 7:05 PM
Why architecture is important & What it is
Habitable Architectures created for people
Enterprise models
Personal information environments
System models, the heavy part
UML Collaboration, a powerful abstraction for architectural topology
Collaboration (role model) specify many instances
CollaborationInstance depicting a concrete topology
Patterns, a literary style for sharing experience
Wrap Entity Beans with Session Beans
Caterpillars Fate: Smooth transition from analysis to design
Summary and Conclusion
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

7. Architectural Design of Distributed Business Systems
WHY ARCHITECTURE?
9/21/2018 7:05 PM
Help create habitable systems
Help create long-lived, robust systems
i. e., aim for simplicity:
simple systems are easy to master
simple systems are easy to build - correctly
simple systems are easy to maintain
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

8. Theory X vs. Theory Y (MacGregor)
Architectural Design of Distributed Business Systems
Theory X vs. Theory Y (MacGregor)
9/21/2018 7:05 PM
Theory X:
Dislike work
Lack ambition
Are irresponsible
Are resistant to change
Prefer to be led rather than to lead
Theory Y
Are willing to work
Are capable of self-control
Are willing to accept responsibility
Are imaginative and creative
Are capable of self-direction
Authoritarian leadership
Inspiring leadership
Rigid, controlling environment
Flexible, supportive environment
Bored, passive workers
Interested, creative workers
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

9. Vision of Distribution anno 1973
Architectural Design of Distributed Business Systems
Vision of Distribution anno 1973
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Mary’s
System
Yngvar’s
System
Jonas’
System
Kari’s
System
Anton’s
System
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

10. The Importance of the User's Mental Model
Architectural Design of Distributed Business Systems
The Importance of the User's Mental Model
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A good conceptual model allows us to predict the effects of our actions.
Without a good model we operate by rote, blindly.
We do operations as we are told; we cannot fully appreciate why, what effects to expect, or what to do if things go wrong.
System Image
SYSTEM
DESIGNER
Design model
USER
USER'S MODEL
Donald A. Norman:
The Design of Everyday Things
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

11. Make IT so simple that even a programmer can understand IT
Architectural Design of Distributed Business Systems
Make IT so simple that even a programmer can understand IT
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Edsger Dijkstra:
Testing can only show the presence of bugs
Testing can never show the absence of bugs
so, the number of bugs in the system when you deliver it is proportional to the number of bugs found during testing
The only way to avoid bugs is not to put them in in the first place
I.E., Keep It Simple, Stupid (KISS)
bugs removed from Windows2000 during testing
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

12. Architectural Design of Distributed Business Systems
Architectural styles
9/21/2018 7:05 PM
Architecture for:
Chaos-Beauty-Flexibility?
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

13. Architectural Design of Distributed Business Systems
Architecture Example
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First Priority: Make it Habitable!
Second Priority: Make it Buildable!
Third Priority: Make it Cost Effective!
First: Architect describes end result.
Second: Architect describes how to build.
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

14. Architectural Design of Distributed Business Systems
RATIONAL's Definition of Architecture "Principles of Architecting Software Systems"
9/21/2018 7:05 PM
Software architecture encompasses the set of significant decisions about the organization of a software system
Selection of the structural elements and their interfaces
Behavior as specified in collaborations among those elements
Composition of these structural and behavioral elements into larger subsystems
Architectural style that guides this organization
Software architecture also involves
Functionality, Usability, Resilience, Performance, Reuse, Comprehensibility
Economic and technology constraints and tradeoffs
Aesthetic concerns
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

15. Architectural Design of Distributed Business Systems
Highlights
9/21/2018 7:05 PM
Why architecture is important & What it is
Habitable Architectures created for people
Enterprise models
Personal information environments
System models, the heavy part
UML Collaboration, a powerful abstraction for architectural topology
Collaboration (role model) specify many instances
CollaborationInstance depicting a concrete topology
Patterns, a literary style for sharing experience
Wrap Entity Beans with Session Beans
Caterpillars Fate: Smooth transition from analysis to design
Summary and Conclusion
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

16. Personal, Integrated Information Environments
Architectural Design of Distributed Business Systems
Personal, Integrated Information Environments
9/21/2018 7:05 PM
Enterprise level
Work processes
UML Object Model
Personal level
User's mental model
UML Collaboration
System level
Design models
All of UML
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

17. Enterprise level Example:Travel Expense
Architectural Design of Distributed Business Systems
Enterprise level Example:Travel Expense
9/21/2018 7:05 PM
Enterprise level
Work processes
UML Object Model
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

18. Two Approaches to Object Orientation
Architectural Design of Distributed Business Systems
Two Approaches to Object Orientation
9/21/2018 7:05 PM
"East Coast Approach":
Object orientation is a smart programming artifact.
An object is an instance of a class.
Simula; Master complexity;
Classification Theory
"West Coast Approach":
Object Orientation is a powerful modeling paradigm.
An object encapsulates state and behavior so that it can collaborate with other objects.
Smalltalk; Personal Information Systems;
Computer Augmentation + Lisp + Simula (+ Operating Systems)
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

19. UML Instance Interaction Diagram Travel Expense Model
Architectural Design of Distributed Business Systems
UML Instance Interaction Diagram Travel Expense Model
9/21/2018 7:05 PM
Peter
(Technical author)
Bill
(Dispatcher)
Joyce
(Sales clerk)
Douglas
(Marketing manager)
Kim
(Methodologist)
Elsie
(Programmer)
Eve
(Software Manager)
(Bookkeeper)
Joe
(Paymaster)
Adam
(Chief Accountant)
Ruth
(President)
John
(Cashier)
Ann
(Customer consultant)
4: authorizedExpenseReport
1: travelPermissionRequest
2: travelPermission
3: expenseReport
5: paymentRequest
We achieve a separation of concern; a collaboration describes the objects involved in one or more functions, describing the objects involved only and focusing on the relevant object properties.
In the collaboration, we study patterns of interacting objects: What are the objects, what are their responsibilities, and how do they collaborate to achieve the system functionality.
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

20. UML Collaboration Diagram Travel Expense Model
Architectural Design of Distributed Business Systems
UML Collaboration Diagram Travel Expense Model
9/21/2018 7:05 PM
Peter
(Technical author)
Bill
(Dispatcher)
Joyce
(Sales clerk)
Douglas
(Marketing manager)
Kim
(Methodologist)
Elsie
(Programmer)
Eve
(Software Manager)
(Bookkeeper)
Joe
(Paymaster)
Adam
(Chief Accountant)
Ruth
(President)
John
(Cashier)
Ann
(Customer consultant)
/ Authorizer
/ BookKeeper
/ Paymaster
/ Traveler
The classifierRole represents the object’s position in the structure and its responsibility for performing its part of the system function.
Objects --> ClassifierRoles
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

21. Behavior: Action-Object Flow Diagram Travel Expense Model
Architectural Design of Distributed Business Systems
9/21/2018 7:05 PM
Behavior: Action-Object Flow Diagram Travel Expense Model
/ Traveler
/ Authorizer
/ BookKeeper
/ Paymaster
Who
Travel perm. request
<Decide>
A Swimlane
for each
Object or
ClassifierRole
<Plan trip>
What
Travel permission
<Buy tickets>
Action
When
<Write exp.
Report>
<Travel>
Expense
Report
<Check OK> <Authorize>
Data Object
Authorized Expense
Report
<Check>
<Bookkeeping>
Payment
Request
<Pay out>
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

22. Pipes and Filters: Travel Expense Model
Architectural Design of Distributed Business Systems
9/21/2018 7:05 PM
Pipes and Filters: Travel Expense Model
/ Traveler
/ Authorizer
/ BookKeeper
/ Paymaster
Who
TravelRecord [request]
<Decide>
<Plan trip>
What
Data Object
changes state
over time
TravelRecord [permission]
<Buy tickets>
When
<Write exp.
Report>
<Travel>
TravelRecord [report]
<Check OK> <Authorize>
TravelRecord [authorized]
<Check>
<Bookkeeping>
TravelRecord [pay]
<Pay out>
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

23. Personal Information Environment
Architectural Design of Distributed Business Systems
Personal Information Environment
9/21/2018 7:05 PM
Personal level
User's mental model
UML Collaboration
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

24. Task: Decide permission Travel Expense Model
Architectural Design of Distributed Business Systems
9/21/2018 7:05 PM
Task: Decide permission Travel Expense Model
/ Traveler
/ Authorizer
/ Authorizer
/ BookKeeper
/ Paymaster
Travel perm. request
<Decide>
Travel perm. request
<Decide>
Travel permission
<Plan trip>
Travel permission
<Buy tickets>
<Write exp.
Report>
<Travel>
Expense
Report
<Check OK> <Authorize>
Authorized Expense
Report
<Check>
<Bookkeeping>
Payment
Request
<Pay out>
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

25. Travel Permission Decision Tool Travel Expense System
Architectural Design of Distributed Business Systems
Travel Permission Decision Tool Travel Expense System
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Traveler
Peter
Period
week 11
Planned cost
USD
Purpose
Attend TOOLS Europe 2001
Current plan for Peter
activity 1
activity 2
activity 3
week
Budget + commitments
Item Budget Committed
Travel 10, ,000
Permit
Reject
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

26. Travel Permission Decision Tool Required Topology
Architectural Design of Distributed Business Systems
Travel Permission Decision Tool Required Topology
9/21/2018 7:05 PM
Traveler
Peter
Period
week 11
Planned cost
USD
Purpose
Attend TOOLS Europe 2001
Current plan for Peter
activity 1
activity 2
activity 3
week
Budget + commitments
Item Budget Committed
Travel 10, ,000
Reject
Permit
/ Planning
Service
/ Authorizer
/ DecisionTool
/ Travel
Service
/ Accounting
Service
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

27. Architecting Distributed Systems
Architectural Design of Distributed Business Systems
Architecting Distributed Systems
9/21/2018 7:05 PM
System level
Design models
All of UML
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

28. Architectural Design of Distributed Business Systems
Highlights
9/21/2018 7:05 PM
Why architecture is important & What it is
Habitable Architectures created for people
Enterprise models
Personal information environments
System models, the heavy part
UML Collaboration, a powerful abstraction for architectural topology
Collaboration (role model) specify many instances
CollaborationInstance depicting a concrete topology
Patterns, a literary style for sharing experience
Wrap Entity Beans with Session Beans
Caterpillars Fate: Smooth transition from analysis to design
Summary and Conclusion
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

29. Enterprise Production Planning & Control
Architectural Design of Distributed Business Systems
Enterprise Production Planning & Control
9/21/2018 7:05 PM
The (toy) sample user interface is a Java Applet that is run from a web browser. The interface interacts with a background service that is also written in Java.
The top bars in the bar chart shows the earliest times when the activities can be performed. The bottom bars show when the activities all have to be done by the same resource, and this resource can only serve one activity at the time.
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

30. UML Use Case Notation Demo Example
Architectural Design of Distributed Business Systems
UML Use Case Notation Demo Example
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ActivityNetworkDemo
UC 2: Frontload
UC 1: Generate test networks
UC 3: Allocate resource
User (Me)
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

31. Use Case 2: Frontloading UML Instance Interaction Diagram
Architectural Design of Distributed Business Systems
Use Case 2: Frontloading UML Instance Interaction Diagram
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fL(t) =
public void
frontLoad (int time )
Project
1:fL(0)
9:fL(19)
Activity-B
7 (4) 10
Activity-D
14 (3) 16
4:fL(10)
2:fL(6)
7:fL(16)
Activity-A
1 (6) 6
Activity-F
18 (2) 19
5:fL(13)
3:fL(6)
Activity-C
7 (7) 13
Activity-E
14 (4) 17
8:fL(17)
6:fL(13)
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

32. The UML Collaboration and the ClassifierRole
Architectural Design of Distributed Business Systems
The UML Collaboration and the ClassifierRole
9/21/2018 7:05 PM
/ RoleName
1: mess1
2: mess2
A collaboration describes how an operation, like a use case, is realized by a set of classifiers and associations used in a specific way. The collaboration defines a set of roles to be
played by instances, as well as a set of interactions that define the communication between the instances when they play the roles.
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

33. The essence of frontloading Collaboration with Interaction
Architectural Design of Distributed Business Systems
The essence of frontloading Collaboration with Interaction
9/21/2018 7:05 PM
/ Activity
/ Successor
/ Predecessor
fL(t1)
fL(t2) *
A many-relation (*) means that the role represents a typical member of the set All other members behave correspondingly
"In an instance of a collaboration, each ClassifierRole maps onto at most one object.”
What are the objects, what are their responsibilities, and how do their collaborate to achieve the system functionality.
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

34. Interfaces in the Basic scheduling collaboration
Architectural Design of Distributed Business Systems
Interfaces in the Basic scheduling collaboration
9/21/2018 7:05 PM
The interfaces specify minimal requirements
to receiving classes
/ Predecessor
/ Activity
/ Successor
fL(t1)
fL(t2)
«Interface»
FrontloadIntf
frontLoad(time)
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

35. Interface Definitions Java
Architectural Design of Distributed Business Systems
Interface Definitions Java
9/21/2018 7:05 PM
public interface FrontloadIntf { public void frontLoad (int t); }
/ Predecessor
/ Activity
/ Successor
fL(t2)
fL(t1)
«Interface»
FrontloadIntf
frontLoad(time)
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

36. The UML Class playing a role in a Collaboration
Architectural Design of Distributed Business Systems
The UML Class playing a role in a Collaboration
9/21/2018 7:05 PM
:ClassName
1: mess1
2: mess2
An Instance of a given class playing the specified role at run time
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

37. Assign classes to roles (Optional)
Architectural Design of Distributed Business Systems
Assign classes to roles (Optional)
9/21/2018 7:05 PM
/ Predecessor :Activity, :Project
/ Activity
: Activity
/ Successor :Activity, :Project
fL(t1)
fL(t2)
«Interface»
FrontloadIntf
frontLoad(time)
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

38. Class Definitions Java
Architectural Design of Distributed Business Systems
Class Definitions Java
9/21/2018 7:05 PM
public class Activity implements FrontloadIntf { private FrontloadIntf[] successors; … … …
public void frontload (int t) {…}
… … … }
/ Predecessor : Activity, Project
/ Activity
: Activity
/ Successor : Activity, Project
fL(t1)
fL(t2)
«Interface»
BackloadIntf
backload(time)
«Interface»
FrontloadIntf
frontLoad(time)
public class Project implements FrontloadIntf{ private FrontloadIntf[] startActivities; … … …
public void frontload (int t) {…}
… … … }
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

39. Architectural Design of Distributed Business Systems
Highlights
9/21/2018 7:05 PM
Why architecture is important & What it is
Habitable Architectures created for people
Enterprise models
Personal information environments
System models, the heavy part
UML Collaboration, a powerful abstraction for architectural topology
Collaboration (role model) specify many instances
CollaborationInstance depicting a concrete topology
Patterns, a literary style for sharing experience
Wrap Entity Beans with Session Beans
Caterpillars Fate: Smooth transition from analysis to design
Summary and Conclusion
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

40. Separate Presentation and Business Objects
Architectural Design of Distributed Business Systems
Separate Presentation and Business Objects
9/21/2018 7:05 PM
WEB Browser
paint();
Button
Tool
ActivityGraph
BarChart
Project
activity-B
activity-D
activity-A
Activity-F
activity-C
activity-E
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

41. An Unrealistic Implementation
Architectural Design of Distributed Business Systems
An Unrealistic Implementation
9/21/2018 7:05 PM
class ActivityGraph extends Canvas {. . .
public void paint(Graphics g) {
. . . // paint frame etc.
Graphics ng = g.create(. . .);
tool.getProject().paintGraph(ng); }
public class Project {. . .
public void paintGraph(Graphics g) {
// collect ranked activities
Activity[][] bucket = rankedActivities();
// Plot activities in each column.
for (int i=0; i < bucket.length; i++) {
for (int j=0; j < bucket[i].length; j++) {
bucket[i][j].paintSymbol(g, new Point (…), grid); }
// draw connections . . .
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

42. Java RMI Remote Method Invocation
Architectural Design of Distributed Business Systems
Java RMI Remote Method Invocation
9/21/2018 7:05 PM
Server
Client
Information Bus
WEB Browser
paint();
Button
Tool
ActivityGraph
BarChart
Project
activity-B
activity-D
activity-A
Activity-F
activity-C
activity-E
Exercise 3:
Suggest an implementation for this system
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

43. The UML Subsystem playing a role in a Collaboration
Architectural Design of Distributed Business Systems
The UML Subsystem playing a role in a Collaboration
9/21/2018 7:05 PM
SubsystemName
1: mess1
2: mess2
A subsystem is a grouping of model elements that represents a behavioral unit in a physical system.
A subsystem offers interfaces and has operations.
The Subsystem hides detail to simplify the drawing, but is neither visible at compile time nor at run time.
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

44. High level Collaboration with Subsystems
Architectural Design of Distributed Business Systems
High level Collaboration with Subsystems
9/21/2018 7:05 PM
Tool
WEB Browser
paint();
Button
Applet
ActivityGraph
BarChart
PlanningService
Project
The Subsystem hides detail to simplify the drawing, but is neither visible at compile time nor at run time.
activity-B
activity-D
activity-A
Activity-F
activity-C
activity-E
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

45. The UML Component playing a role in a Collaboration
Architectural Design of Distributed Business Systems
The UML Component playing a role in a Collaboration
9/21/2018 7:05 PM
ComponentName
1: mess1
2: mess2
A Component represents a modular, deployable, and replaceable part of a system that encapsulates implementation and exposes a set of interfaces.
The Component simplifies the system. It supports separate compilation and deployment; the separation is visible at run time.
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

46. High level Collaboration with UML Components
Architectural Design of Distributed Business Systems
High level Collaboration with UML Components
9/21/2018 7:05 PM
Tool
PlanningService
WEB Browser
paint();
Button
Responsibility
Applet
ActivityGraph
BarChart ?
«Interface»
Project
Project
activity-B
activity-D
activity-A
Responsibility
Activity-F
activity-C
activity-E
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

47. Assign Components to Physical Nodes
Architectural Design of Distributed Business Systems
Assign Components to Physical Nodes
9/21/2018 7:05 PM PC
Tool
Application Server
Planning
Service
The Node is a container of components. In itself, it does not offer operations to its environment, so it cannot be a classifierRole.
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

48. Architectural Design of Distributed Business Systems
Some UML Definitions
9/21/2018 7:05 PM
A Collaboration describes how an operation, like a use case, is realized by a set of classifiers and associations used in a specific way. The collaboration defines a set of roles to be played by Instances, as well as a set of interactions that define the communication between the instances when they play the roles.
The Instance is encapsulated. It has identity, interface and state.
An instance of a given Class can play one or more roles at run time. A ClassifierRole can be implemented by many ways.
A Subsystem is a grouping of model elements that represents a behavioral unit in a physical system. A subsystem offers interfaces and has operations.
A Component represents a modular, deployable, and replaceable part of a system that encapsulates implementation and exposes a set of interfaces.
A Node is a run-time physical object that represents a computational resource,
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

49. UML Diagrams (Architecturally Significant)
Architectural Design of Distributed Business Systems
UML Diagrams (Architecturally Significant)
9/21/2018 7:05 PM
Build-time Diagrams (Code and Code Management)
Class Diagrams
Deployment Diagrams
Component Diagrams
Run-time Diagrams
Use Case Diagrams
Collaboration Diagrams (Objects, ClassifierRoles, Subsystems, Components)
Interaction & Sequence Diagrams
Object Diagrams
Statechart Diagrams
Activity Diagrams / Action-Object Flow Diagrams
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

50. Architectural Design of Distributed Business Systems
Highlights
9/21/2018 7:05 PM
Why architecture is important & What it is
Habitable Architectures created for people
Enterprise models
Personal information environments
System models, the heavy part
UML Collaboration, a powerful abstraction for architectural topology
Collaboration (role model) specify many instances
CollaborationInstance depicting a concrete topology
Patterns, a literary style for sharing experience
Wrap Entity Beans with Session Beans
Caterpillars Fate: Smooth transition from analysis to design
Summary and Conclusion
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

51. Architectural Design of Distributed Business Systems
Design Patterns
9/21/2018 7:05 PM
ChristopherAlexander, Architect:
Each pattern describes a problem that occurs over and over again in our environment and then describes the core of the solution to that problem in such a way that you can use this solution a million times over without ever doing it the same way twice.
Jim Coplien and Doug Schmidt, Software Engineers:
A clear statement of a problem and its context.
Offering a concrete solution addressing the problem
A clear statement of the forces that motivate the solution.
A pattern tells you how to solve a problem.
A framework solves the problem for you.
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

52. Architectural Design of Distributed Business Systems
Highlights
9/21/2018 7:05 PM
Why architecture is important & What it is
Habitable Architectures created for people
Enterprise models
Personal information environments
System models, the heavy part
UML Collaboration, a powerful abstraction for architectural topology
Collaboration (role model) specify many instances
CollaborationInstance depicting a concrete topology
Patterns, a literary style for sharing experience
Wrap Entity Beans with Session Beans
Caterpillars Fate: Smooth transition from analysis to design
Summary and Conclusion
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

53. Architectural Design of Distributed Business Systems
Wrap Entity Beans with Session Beans-1 Ed Roman, TheServerside.com, August, 2000
9/21/2018 7:05 PM
"Artist's Impression"
Business API
Business Logic S S
Persistent Data
Data Logic E E
JDBC
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

54. A Real Example Application Execution Architecture
Architectural Design of Distributed Business Systems
A Real Example Application Execution Architecture
9/21/2018 7:05 PM
Web
Browser UI
«web pages»
Web
Server
UIControl
«JavaServer
Page» 1
Data
Storage
base 1
Mapper
«EntityBean»
Application
Server
Activity
«Stateful
SessionBean» 1
Task
«Stateless
SessionBean» *
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

55. Architectural Design of Distributed Business Systems
Highlights
9/21/2018 7:05 PM
Why architecture is important & What it is
Habitable Architectures created for people
Enterprise models
Personal information environments
System models, the heavy part
UML Collaboration, a powerful abstraction for architectural topology
Collaboration (role model) specify many instances
CollaborationInstance depicting a concrete topology
Patterns, a literary style for sharing experience
Wrap Entity Beans with Session Beans
Caterpillars Fate: Smooth transition from analysis to design
Summary and Conclusion
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

56. Caterpillar's Fate - 1 Norman Kerth, Coplien's book
Architectural Design of Distributed Business Systems
Caterpillar's Fate - 1 Norman Kerth, Coplien's book
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Synchronization
of Concurrent Threads 9.
Shape of Program 3.
Collaborative
Work Packets 1.
Concurrent
Threads of Execution
The main patterns
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

57. Architectural Design of Distributed Business Systems
Highlights
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Why architecture is important & What it is
Habitable Architectures created for people
Enterprise models
Personal information environments
System models, the heavy part
UML Collaboration, a powerful abstraction for architectural topology
Collaboration (role model) specify many instances
CollaborationInstance depicting a concrete topology
Patterns, a literary style for sharing experience
Wrap Entity Beans with Session Beans
Caterpillars Fate: Smooth transition from analysis to design
Summary and Conclusion
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

58. Personal, Integrated Information Environments
Architectural Design of Distributed Business Systems
Personal, Integrated Information Environments
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Habitable Systems
Theory X for inspiring organizations
Explicit Users' Mental Models
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

59. Control Components through their Responsibilities and Interfaces
Architectural Design of Distributed Business Systems
Control Components through their Responsibilities and Interfaces
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Tool
Responsibility ?
«Interface»
Project
PlanningService
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

60. Plan Behavior Who - What - When
Architectural Design of Distributed Business Systems
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Plan Behavior Who - What - When
/ Authorizer
/ Paymaster
/ BookKeeper
/ Traveler
<Plan trip>
TravelRecord [request]
<Decide>
TravelRecord [permission]
<Buy tickets>
TravelRecord [authorized]
<Check>
<Bookkeeping>
TravelRecord [pay]
<Pay out>
<Write exp.
Report>
<Travel>
TravelRecord [report]
<Check OK> <Authorize>
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

61. Instruct implementors and maintainers
Architectural Design of Distributed Business Systems
Instruct implementors and maintainers
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Objects
Collaboration links
Backplane (Container)
Net
Hardware
Operating System
Thanks to Øystein Myhre for this illustration
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug

62. Questions ?
Comments ?
Architectural Design of Distributed Systems

63. Architectural Design of Distributed Business Systems
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More details ….
Coplien, James O. and Douglas C. Schmidt, ed. Pattern Languages of Program Design, Addison-Wesley, 1995.
Reenskaug, Wold, Lehne: Working With Objects. Manning/Prentice Hall ISBN The reference work. This book is out of print. A .pdf version kan be downloaded free from above website.
Theory: Egil P. Andersen: Conceptual Modeling of Objects. A Role Modeling Approach. Dr Scient thesis. Dept. of Informatics, University of Oslo. 4 November The theory of role modeling ftp://ftp.nr.no/pub/egil/ConceptualModelingOO.ps.gz
Unified Modeling Language (UML). Object Management Group. UML Draft Specification v UML Draft Specification v OMG DOC#: ad/
Donald A. Norman: "The Design of Everyday Things." Doubleday/Currency ISBN
Douglas MacGregor: “Human Side of Enterprise : 25th Anniversary Printing” McGraw-Hill 1985; ISBN:
Alexander, Christopher, et al. A Pattern Language, Oxford University Press, New York, 1977.
Frank Buschmann: Pattern-Oriented Software Architecture. Wiley 1996; ISBN:
IBM WebSphere:
Architectural Design of Distributed Systems
©2001 Trygve Reenskaug