How do you achieve agility with Service Oriented Architecture and Enterprise Application Integration

1. Agile SOA
Agile EAI
How do we achieve agility
in Enterprise Integration?

2. What is Enterprise Integration?
 Enterprise Integration is the main activity
of an in-house software development organization.
Building software products is not our main activity.
 Why?
DTE is in a mature industry and a relatively stable
environment. As a result we can buy almost all of the
software we need cheaper than we can build it.
 But we still need to create interfaces
for almost everything we buy.
 Enterprise Integration means building
application-to-application (A2A)
and business-to-business (B2B) interfaces.

3. Contents
Context What is Enterprise Integration?
Analysis The message is the feature-set.
Planning Release planning is a multi-player game.
Managing Concurrent engineering requires a
different approach to project management.
Testing Re-usable components and services require
automated test suites.
Deploying Deployment requires configuration control.

4. The message is the feature.
 The message is the feature in EAI and SOA.
 Analysis: Enterprise Patterns.
 How to identify the messages
quickly and simply.
 Messages are speech acts.
 Identify messages in complete sentences.
 Nouns identify business objects (data entities).

5. The message is the feature … because:
 Enterprise Integration implements communications
between business processes.
 The simple way to plan the integration features
is to think about the messages
that are exchanged between business processes.
 A major application is the IT proxy or interface
for some business process.
 A2A or B2B -- It is the same thing.
What if your enterprise decides to out-source a business process?

6. Analysis: What to look for …
In-coming Messages Out-going Messages
 Request  Response
 Work Order Request  Work Order Complete
 Question  Answer
 Work Order Status  Progress / Exception
 Entity State (data)  Business Object (data)
 Subscribed Event  Published Event
 External Event  Event I Observe or Validate
of Interest to Me of Interest to Others
 Data Subscribed  Data Published

7. Messages are speech acts.
Express each message as a complete sentence.
 Request: Please install a new service S
at location L.
 Response: Service S installed at location L.
L
 Question: What is the status of work order W?
 Notice: Inventory asset A moved
from location L1 to location L2.

8. Noun ==> Business Object
Write each message as a complete sentence.
Use nouns in a consistent way.
Avoid application-specific jargon.
 Request: Please install a new service S
at location L.
L
 Response: Service S installed at location L.
L
 Question: What is the status of work order W?
W
 Notice: Inventory asset A moved
from location L1 to location L2.
L2

9. Message Patterns ==> Design Patterns
 Request-Response (work order … publish-subscribe)
 Client: Please replace meter M at location L
with a meter of type T.
 Service: Meter M1 with reading R1 replaced
with meter M2 reading R2.
 Question-Answer (query … remote procedure call)
 Client: Order status S = What is the status of work order W?
 Service: Work order W has status S.
 Event Notice (event … publish-subscribe)
 Publisher: Work order W will be delayed due to problem P.
 Subscriber: (updates local work management)

10. Example: Metering Service
In-coming Messages Out-going Messages
 Request: (We accept the request.)  Request: (We delegate work to …)
Please install a meter of type T Please install a meter of type T
for service S at location L. for service S at location L.
 Query: (We answer the question.)  Query: (We ask the delegate.)
Metric M = How much energy Status S = What is status
has been used at meter M? of work order W?
 Response: (When the work is  Publish: (We publish the event.)
done, the delegate responds with work Meter M is monitoring service S
order results.)
Work order W completed at location L.
normally with results R
 Notice: (We subscribe to notice.)
Meter M needs a new battery
before date D.

11. Business Collaboration - a Use Case Scenario
From To Message
Client Metering Please replace meter M at location L with a meter of type T.
Service (This is work order WO-A received from the Client.)
Metering Field Please replace meter M at location L with a meter of type T.
Service Service (This is work order WO-B delegating work to Field Service.)
Field Metering Meter M1 reading R1 replaced with meter M2 reading R2.
Service Service (Work order WO-B completion report received from Field Service.)
Metering Client Meter M1 reading R1 replaced with meter M2 reading R2.
Service (This is work order WO-A completion report sent to Client.)
Metering Subscribers Meter M1 reading R1 replaced with meter M2 reading R2.
Service (This event notice is published for all interested subscribers.)
Subscriber (self) Each subscriber updates its world-model (stored in a database)
to reflect the business event. There may be additional side-effects.

12. Release planning
is a multi-player game.
Planning and Budgeting
 Business Process -- owner / governor
 Application Portfolio -- owner / governor
 Component Library -- architect / planner
Design and Construction
 Software Architect -- designer / planner / coordinator
 Project Manager -- planner / coordinator
 Software Developer -- builder / tester / operator / maintainer

13. How do you plan a release?
A release is a coherent set of features
 for a specific audience (UI feature set)
 for a specific process (EAI feature set)
Ask which features are necessary and sufficient.
 Is data replication necessary and sufficient?
 Is passive notification of exceptions sufficient?
 Is workflow needed?

14. Interface Packaging ==> Wrappers
Create services by building wrappers
on business services,
within
legacy applications,
and the message delivery system. wrappers
Business Process A Business Process B
Message Delivery Service
Application publish subscribe Application
1 4
Application Question Application
2 5
Application Answer Application
3 6

15. Business Service Wrapper
Business Process == Business Service
Request Application
Response
A
Business
Application
Process B
Workflow
Published Event Application
Subscribed Event C

16. Legacy Application Wrappers
Business Process == Business Service
Request Application
Response A
Application
Question-Answer Database
B
Published Event Application
Subscribed Event C

17. Work Breakdown Structure
Sender Receiver
 Detect the event / need.  Receive the request.
 Assemble the business objects  Translate the business objects
into the message. into local form.
 Send the message.  Call the equivalent method.
What about workflow? Workflow Responsibilities
 Workflow is essential  Delegate work as needed.
for handling
 Respond to process exceptions.
business-process exceptions.
 Each process manages  Publish events.
its own workflow  Feed back results.
and no other workflow.  Collect statistics.

18. Concurrent Engineering
Who should do which components?
 Each application’s maintenance team has the local knowledge to …
 Write logic to detect events.
 Write logic to translate between local representation and standard representation.
 Write application wrappers (API).
 Each business-process team has the knowledge to …
 Define and implement local workflows.
 Define and implement end-to-end tests.
 Design business-process monitoring (dashboard displays and reports).
 A tooling team has the skill and focus to …
 Create commonly-used components and services. Messages
 Create and maintain a repertoire of common business objects. and
business objects
 The project coordinators have the skills and tools to … provide
 Identify project-to-project dependencies. clear and succinct
points of contact
 Coordinate release plans. for
design discussions
and
release coordination

19. SOA requires automated test suites.
Why do you need automated test suites?
 If you have a service with 10-20 clients,
and you are about to deploy a new release …
You can ask all of the clients to re-test.
-OR- Some services
You can exhaustively test the service have 100’s
to assure backward compatibility.
of clients
 For a service of any complexity,
automated tests are the only robust solution.
 By definition, integration tests cross system boundaries.
 Business process tests tend to require set-up, tear-down, etc.

20. Configuration Control Challenges
 Where is each component used?
 To whom do we send release notices?
 Where is this service used?
 When the service is down, who is affected?
 Which version is used where?
 When a method is deprecated, who is at risk?

21. Summary
 Business processes communicate via messages.
 That means the message is the feature (the user story)
for agile EAI and agile SOA.
 Secret Sauce:
Identify each message with a complete sentence.
 Secret Organization:
Concurrent engineering reduces time to solution.

22. To achieve
EAI / SOA agility:
Focus on the
business-process
message exchanges.