Implementing SOA

Key Success Factors for SOA

• Understanding
• Collaboration
• Management support
• Careful introduction
• Homework

SOA or not to SOA

• Calculate the potential benefits of SOA versus costs
• Don't replace existing, working solutions with SOA
• Don't try to apply SOA to critical projects unless you are certain you have enough experience
• In case of mass-data processing or real-time systems make sure that the performance will not be the issue

Introducing SOA

• SOA IS A STRATEGY
• Gradually introduction
• Impossible to get it right in the first place
• Hence, you can’t make all the decisions up front
• Remember, you cannot buy SOA nor you cannot have a consultant who tell you exactly what to do

SOA Governance

• Controlling the development and operation of software
• Making sure that people do what’s “right.”

Governance Basics

• Policies: define what’s right
• Processes: enforce policies
• Metrics: provide visibility and verify policy enforcements
• Documentation (for governance)
• Service management (repositories and registers)
• Monitoring
• Change and configuration management

Governance Template

• Visions, objectives, business case, and funding model
• Reference architecture
• Roles and responsibilities
• Policies, standards, and formats
• Processes and lifecycles

Visions, objectives, business case, and funding model

• Answer the question of why to introduce SOA.
• Funding model determines how the initial overhead of introducing SOA and new services will be paid for
• Explains SOA ROI

Reference architecture

• Reference that demonstrates your fundamental architectural decisions
• Preferred technology
• Message exchange patterns
• Meta model
• Primary and canonical types
• Preferred sources of standards (as Web Services has many)

Roles and responsibilities

Make it clear who drives and cares about the issues especially

• Architectures
• Technologies
• Process enforcement
• Finance control

Processes and life-cycles

• How the services are introduced
• How the services are disposed

Processes in practise

• Official process
• Perceived process
• Actual process

Policies

A law, examples:

• Every Web Service shall use SOAP protocol
• No enum type is allowed

A Guideline

• WSDL should comply to 1.2 standard

Policy Template

• The topic
• Problem the policy addresses
• Whether the policy is mandatory (a law or a guideline)
• The consequences for the infrastructure
• The consequences for service providers
• The consequences for service consumers

Central SOA Team

• Coordinates all the steps of implementing SOA
• Establishes and governs SOA
• Consolidates
• Standardizes
• Should not create another Ivory Tower

The SOA Pilot

• It is not a prototype (i.e. it must produce something which is supposed to work, not thrown away)
• Project should be non-critical but of palpable business value

The SOA Pilot

• Simple MEPs (e.g. synchronous and asynchronous)
• Minimal number of data types
• Lightweight ESB, not necessary used later
• Create only services you need, not you might need them in the future
• Think big, start small (don't fall into analysis paralysis)

SOA Projects

• There must be one diagram of the whole system
• Introducing new person should be relativity easy (proper induction documentation)
• Reviews and retrospective
• Movies with explanations
• External reviews and support
• Parallel planning and reviews for critical projects

Bottom up vs Top down

• Developer driven
• Business project driven
• IT driven
• Top management driven

SOA Maturity Models

• CMMI http://www.sei.cmu.edu/cmmi/index.cfm
• IBM Solutions
• OMG http://soa.omg.org/Uploaded%20Docs/SOA/SOA_Maturity.pdf
• The Open Group (OSIMM)

CMMI

1. Initial: services that represent the initial learning and initial project phase of SOA adoption
2. Managed: services using standards that are set as to the technical governance of SOA implementation
3. Defined: services on the partnership between technology and business organizations in order to assure that the use of SOA provides clear business responsiveness
4. Quantitatively managed: when you focus on the implementation of internal and/or external business processes
5. Optimizing: when you have “optimized business processes SOA,” so that “the SOA information systems becomes [sic] the ‘enterprise nervous system.’”

Service Orientation Red Flags

• High-performance/real-time systems
• High-throughput systems
• Business-to-business interactions involving intricate transaction semantics
• Batch processes
• Data warehouses
• Any technology system or business unit where tight coupling and/or monolithic integration is desirable

How can you tell a good consultant?

• Good consultants do whatever they can to make themselves unnecessary
• You cannot fully rely on external consultant, internal knowledge of at least a couple of people is a must