White Paper Version 2.0_ March 2010 Service Oriented ...

1

White Paper Version 2.0_ March 2010

Service Oriented Architecture (SOA) Think big, start small, scale fast

Renewtek White Paper: Service Oriented Architecture.

2 www.renewtek.com Copyright © Renewtek Pty Ltd

TABLE OF CONTENTS

1. INTRODUCTION 1

2. DEFINITION OF SOA 1

2.1 STRATEGIC ENTERPRISE ARCHITECTURE 1

2.2 SOA: WHAT IT IS AND WHAT IT’S NOT 4

2.3 COMPARISON WITH EAI 4

2.4 ROBUST TECHNOLOGIES AND SUSTAINABLE SOLUTIONS 5

3. BUSINESS VALUE OF SOA 6

3.1 SOA ADOPTION AND USAGE 6

3.2 DYNAMIC AND COMPETITIVE BUSINESS ENVIRONMENT 6

3.3 IMPROVING THE IT VALUE PROPOSITION 7

3.3.1 BUSINESS TRANSFORMATION 8

3.3.2COMMERCIAL LEVERAGE 9

3.4 COMPELLING BUSINESS DRIVERS 9

4. SOA IN PRACTICE 11

4.1 CASE STUDY 11

4.2 DELIVERING ON THE PROMISE 12

5. CONCLUSION 13

6. INFORMATION 14

This document has been prepared for the sole use of the recipient. Renewtek Pty Ltd is committed to providing quality information to its customers. While every effort has been made to ensure accuracy, currency and reliability of the information within these documents, Renewtek Pty Ltd accepts no responsibility for errors, omissions or amendments made since the time of publishing. Renewtek will not be responsible for the consequence of reliance upon any opinion or statement contained herein or for any omission. The information contained herein is subject to changes; revisions and new editions may be issued to incorporate such changes.



1. Introduction

Very few IT executives can truly say they keep up with business driven changes to their organisation’s IT environment. Most IT teams have some difficulty fulfilling business demands for new functionality, new integration requirements and business process changes while also meeting cost and timeframe expectations. Service Oriented Architecture (SOA) has emerged as both a tactical and strategic approach to redress this balance.

SOA delivers enhanced business agility, improving IT responsiveness to the rapidly changing business needs intrinsic to a dynamic and competitive business environment.

This Renewtek White Paper discusses:

♦ What SOA is and what it’s not.

♦ The business value of SOA.

♦ SOA in practice.

2. Definition of SOA

2.1 Strategic enterprise architecture

SOA is an approach to architecture that is business driven and enables the alignment of the organisation’s strategic enterprise architecture with the organisation’s existing disparate technology protocols and implementations.

SOA organises business processes, activities or information into Services. These services interact with each other through business processes and the SOA infrastructure. For example, a customer order or stock availability enquiry. IT can build a portfolio of Services that can be rapidly and effectively orchestrated to fulfil business requirements

Tactically, an SOA can assist IT to deal with a variety of specific problems that they often encounter, such as, integrating new requirements within a legacy application environment.

Effectiveness of SOA

Adopting SOA principles can reduce application development costs and integration timeframes by as much as 50 percent. CIO Magazine June 2006

Service Oriented Architecture (SOA) is a paradigm for organizing and utilizing distributed capabilities that may be under the control of different ownership domains (OASIS Reference Model for SOA v1.0 May 2006).



Strategically, SOA enables IT to support business process transformations. SOA promises a future state where IT, drawing from a Services Directory, can flexibly and rapidly deploy and update business processes in unison with changing business needs.

The goal of SOA is to decompose large, complex IT requirements into smaller, simpler components (called Services) and to achieve a loose coupling among interacting software systems by using services. A Service is a component of work, or step of a process, performed by service provider to meet the end results desired by service consumer. Services are designed to be reused in a variety of business contexts. Service providers and service consumers are implemented as discrete software components (usually called ‘software agents’).

SOA is an IT architectural paradigm, an approach to designing and delivering IT solutions. Specific SOA implementations are constructed in accordance with the guiding principles of SOA: loose coupling, business service granularity (fine grained or coarse grained) and technology independence through open standards based protocols and languages. IT solutions implemented on the SOA should then conform to this specification and align with the IT architecture and governance model for the enterprise1.

IT solutions are implemented as application systems utilising communications and server infrastructure. Under an SOA approach, the application systems layer is organised in components consistent with business activities and abstracted from the underlying communications and server infrastructure. The construction of application solutions to meet business demands are then much less dependent on that infrastructure. This abstraction provides significant benefits to both IT and its business customers.

The main SOA concepts consistent across all SOA implementations:

♦ A Service is a component of work performed by a service provider to meet the end results desired by a service consumer.

♦ The Service Contract defines the behaviours of the Service so that it can be implemented as a discrete software component and used by other software.

♦ The Service Description 2 details the technical parameters for invocation of the Service, what the Service does and what security protocols apply.

1 This may require the use of Web Services or J2EE or .NET. Each of which is a specific protocol applicable to Services.

2 Recognised protocols for Service Description are WSDL and ebXML.



The principles of Stateless Services and Idempotent Requests improve scalability, performance and reliability in an SOA implementation. See Table 1.

Table 1. Factors impacting SOA scalability, performance and reliability.

Advertising and Discovery of Services is important for a specific SOA implementation to scale-up beyond the deployment of a few Services. In large organisations a central repository and registry of Services is vital to enable effective reuse and sharing across functional units. Any significant SOA requires implementation of a Services Registry or Services Directory 3.

3 There are protocols for these: ISO/IEC 11179 Part 3 (metadata registries), the ebXML Registry-Repository Technical Specification and UDDI.

Factor Description

Stateless Services

Every request sent by a consumer Service to provider Service must contain all the information for the provider service to complete it process. That's because the provider Service does not have to store 'state' information between requests and so every request is generic. It also makes a provider Service more reliable as there are no intermediate 'states' and therefore recover from a partial failure is simplified.

Stateful Service

The use of stateful Services is necessary at times, or is difficult to avoid in some situations (eg when establishing and maintaining a secure session or when providing customised Service). A stateful Service requires both the consumer Service and the provider Service to share a specific context held within the messages exchanged between the provider and the consumer.

Compared with the use of stateless Service, the use of stateful Services reduces the overall scalability and increases the tightness of the coupling between a provider Service and a consumer Service.

Idempotent Request

Adopting the principle means that duplicate requests received by a provider Service will have the same effect as a unique request. This improves overall reliability because Service providers and consumers can simply repeat a request in the event of failure.



2.2 SOA: what it is and what it’s not

SOA is frequently misunderstood or misconstrued (or both). It’s not a specific technology. It’s not just Web Services, J2EE, .NET, CORBA or ebXML. These are ‘only’ protocols that may or may not be embodied in a specific SOA implementation. In fact, Services could be implemented in any language (eg COBOL or Java), although Services will ideally use a standard invocation protocol such as XML/SOAP to be compliant with SOA principles.

SOA and Object Oriented (OO) design have both evolved from component-based architecture models but they differ in certain respects. Most notably in terms of data encapsulation in OO design and data independence in SOA. But SOA is not a data-centric architecture; it is vigorously business-centric.

Experienced IT practitioners view SOA as an evolution of the move away from monolithic systems, decomposing complex application functionality into components. SOA continues, expanding existing models such as client-server; 3 or N-Tier architecture, OO design and Enterprise Application Integration (EAI).

2.3 Comparison with EAI

EAI establishes an integration layer that enables an organisation to move

information from one application system to another. Traditional EAI is a

common but often expensive, proprietary and resource intensive means of

integrating information from legacy application and database silos.

Recently, vendors of traditional EAI software products (eg Tibco, WebMethods) have repositioned these products as the technology of SOA. The traditional EAI products have been re-engineered and extended to incorporate aspects of SOA. These SOA incarnations of EAI are typically centred around and to referred to as.

However, there remains a fundamental difference between SOA and the SOA enhanced EAI. In an EAI implementation, the bus provides a central EAI manager and common information model; and the EAI manager is in-control of all connections. Whereas in an SOA implementation, each system is a ‘peer’ on the same level, collaborating independently using Services found by referencing a Registry or Service Directory. This further level of abstraction provided by SOA significantly enhances its flexibility and agility over EAI.

Enterprise Application Integration (EAI) is a set of technologies that allows the movement and exchange of information between different applications and business processes within and between organizations (The Integration Consortium, 2006).



In contrast with EAI, SOA improves IT responsiveness to business demands by establishing the independence of Services and by:

♦ Minimising any interdependence among application development teams.

♦ Minimising the dependence of application development teams on the group(s) responsible for the organisation’s integration layer and middleware infrastructure.

2.4 Robust technologies and sustainable solutions

In a legacy IT environment, there are often many different communications protocols used for process integration4. In most organisations, the protocol(s) currently used in particular situations are probably just an ‘accident’ of the application system, its infrastructure and the project team’s choice of the most expedient implementation at the time.

In an SOA environment, while all of the protocols mentioned above could potentially be used to access a Service, a Service can be defined once only, but may have many implementations with differing access protocols. That is, a single Service can be exposed in many ways so as to allow access via multiple protocols. This ensures the integrity of each Service. It is then the responsibility of the Service consumer to decide which protocol best matches a particular situation (eg to meet performance, security or reliability requirements) for their access and use of that Service. These requirements should be met by the ESB.

Communications using Internet-based protocols such as HTTP and SMTP are by design inherently unreliable and are not able to support assured or ordered delivery. A key element required for a robust and sustainable solution is a messaging layer that supports differing Quality of Service requirements, from best effort to ensured guaranteed delivery, duplicate message elimination and message delivery ordering.

The ‘pure’ SOA environment allows and supports the disciplined use of standard and commoditised protocols. However, an obvious side effect of providing multiple ways to access a Service is the overhead in development to

4 For example, one organisation might use all of HTTP, HTTPS, a message broker such as JMS, MQ or MSMQ, etc., CORBA and SMTP.

The messaging layer

♦ Guaranteed delivery ensures that a message is delivered at least once.

♦ Duplicate message elimination ensures that a message is delivered (or processed) at most once.

♦ Message delivery ordering guarantees that messages in a sequence are delivered in the order sent.



provide the necessary layers of technology. To make SOA easy, BEA WebLogic, WebSphere etc, for example, enable the simplified construction of many different protocol wrappers to a Service. This dramatically aids Service consumption and by facilitating the use of the most appropriate messaging protocol(s), ensures a more scalable and robust solution.

To be sustainable and fully scalable across the enterprise or extending beyond the boundaries of the enterprise, an SOA implementation needs to have the appropriate governance practices. With the appropriate governance model, investment in new Services is more easily amortised through reuse because Services can be more effectively provided and consumed.

An enterprise that has adopted SOA as its primary approach to enterprise architecture must also use the principles of SOA to implement or complement a rigourous IT governance model.

3. Business value of SOA

Often explanations about SOA are very much about IT methods and toos. However, while SOA has a particular technical definition, it is just as importantly about what business wants from IT.

3.1 SOA adoption and usage Adoption of SOA is moderated by three critical factors:

♦ SOA is not always perceived to be a short-term priority; rather it is seen as a high-priority objective for the medium-term (3 to 5 years out).

♦ Implementation challenges, not the least of which is often a lack of in-house skills to architect and develop SOA infrastructure and solutions.

♦ Business management have been slow in recognising the compelling value propositions for adopting SOA.

Even so, the rate of adoption and usage is increasing as its potential is now being recognised within many organisations.

3.2 Dynamic and competitive business environment Globalisation of the economy is shifting the focus of competition from enterprise versus enterprise to value-chain versus value-chain. In this new arena, collaboration is vital to the competitive end-to-end performance of a business process. The ‘business’ expects IT to have the agility, responsiveness and flexibility to support the fast-changing processes and strategies necessary to be competitive in this very dynamic business environment.



The challenge for IT is to establish and maintain order in this environment while also being more agile and faster in delivering solutions.

Business requirements call for the integration of data, applications and technologies that have been deployed as silos of functionality. These requirements also demand IT to extend the use of previously installed commercial ‘off the shelf’ packaged software outside the enterprise and integrate the value-chain with customers and suppliers.

The ‘business’ expects IT to:

♦ Be agile and flexible while continuing to reduce costs.

♦ Employ quality and governance practices while achieving fast-cycle times from requirements to delivery.

♦ Deliver robust and sustainable solutions that add-value to the business while being responsive to change.

The realisation is that the technical platform must enable on-demand process integration and service delivery.

However, as is often the case with infrastructure investments, the business investment can be difficult to quantify and justify for an individual business unit or requirement.

3.3 Improving the IT value proposition

Business owners of IT solutions are often surprised by the cost of what they perceive to be ‘simple’ application changes. A significant component of these costs result from the complexity of integrating legacy systems across business functions (legacy applications that were developed and deployed as functional ‘silos’), integrating new functionality with existing applications and the impact that changing business processes and enabling customer/supplier connections has on legacy systems. The need for businesses is respond to market forces and conditions by rapidly changing processes, launching new initiatives, satisfying customer demands and defending against competitor pressure. Overall the cost of maintenance of integrated IT application environments is rising rather than falling.

The SOA value proposition:

♦ Faster cycle-times from business requirement to implementation.

♦ Reduced ongoing costs.

♦ Robust, standards-based technologies.

♦ Vendor independence.



From both a business and IT perspective, there is a need to improve the IT value proposition.

SOA reduces complexity. In the SOA environment IT can deliver what the business demands ― the required functionality or processes ― by connecting new functionality, existing application capabilities and packaged application solutions. Using Services, IT can accomplish this rapidly and effectively.

Services can be quickly connected to build solutions consistent with the required business processes and organisation or role-based structures. With SOA, the enterprise spends much less time on the technical problems of integration. This significantly reduces the overall cost of both building and maintaining the integrated solution(s).

3.3.1 Business transformation

The business value of SOA is not only in the reduced cost of building and maintaining integrated solutions. It is also in the benefit of extending and connecting the enterprise into customer and supplier business processes.

SOA enables the transformation of an integrated solution from one constrained within the enterprise to a business process that is exposed to the entire value chain. This represents the real transformational value of SOA

Enabling this is the abstraction of the Service layer. In the SOA environment this is achieved by building processes composed as Services, which in turn, may be exposed as Services. Meaning an entire business process can be exposed to suppliers or customers and embedded into their processes. Using SOA to achieve this externalisation of the business process achieves far more that simply connecting front-end functionality with back-end applications.

It would be a mistake to regard the reduction in the cost of integration derived from SOA as the only benefit. SOA also delivers enhanced business agility by improving IT responsiveness to the rapidly changing business needs intrinsic to a dynamic and competitive environment.

In an SOA environment, IT can rapidly deliver what the business demands by orchestrating sequences of Services to fulfil new business process requirements or adapt modified business processes. New functionality, existing application capabilities and packaged application solutions can all be quickly connected to build robust integrated solutions.



3.3.2 Commercial leverage

In the J2EE world, the goal was for the application container to provide code portability. In SOA, interoperability and abstraction are considered to be far more important characteristics ― why get involved in the complexity of J2EE to build portable code when with SOA the code can stay where it is and still deliver the flexibility demanded by the business?

This comparison highlights how SOA is enabling abstraction and why SOA is so effective in building enterprise IT flexibility at a number of levels:

♦ By decomposing applications and/or business processes (eg aligning process-steps and Services and then orchestrating sequences of Services to deliver new or modified business processes without having to rewrite the applications).

♦ By decoupling applications from the system environments (eg where an Oracle or BEA platform is used but without requiring the application to understand the technologies used within these platforms).

♦ By decoupling the infrastructure from the applications that run on it (eg Storage Area Networks (SANs) consolidate the physical storage and provide storage as a Service without requiring the application system to know the precise physical nature of the storage).

The flexibility and interoperability afforded by SOA means an enterprise is freed from lock-in to proprietary systems (eg a particular vendor’s hardware or packaged application). This empowers an organisation to negotiate more favourable commercial terms because it becomes feasible to migrate to alternative or commoditised infrastructure and alternative business solutions. A business can use SOA to achieve platform independence and establish competitive leverage among its vendors.

3.4 Compelling business drivers

Without a compelling business driver, any impetus IT may have for SOA risks being mired in the legacy technology environment and constrained to only incremental progress towards an enterprise-wide SOA implementation. However, justifying an investment in an enterprise-wide SOA implementation from an IT perspective is likely to be very similar to developing a business case for server infrastructure without the business applications running on them ― difficult to quantify with tangible costs and benefits.

Return on Investment propositions for SOA may be based on medium- or long-term views of revenue protection (ie sustaining the application platform and protecting the business’s market share and revenue) or on the basis of forecast reductions in the ongoing cost of application support and



maintenance or on reduced development costs. Unfortunately, these approaches are unlikely to yield more than a fairly rubbery set of figures.

Despite these apparent difficulties, it is possible to develop a compelling business case for the introduction and use of SOA. Drawing on Renewtek client engagement experiences, a number of scenarios can be identified where there is clearly potential to substantiate the SOA ROI. For example:

♦ Planning for the replacement of a legacy application. The migration strategy could entail the use of Services to gain a level of independence from the legacy application. Then progressively replacing components of the legacy application with an absolute minimum of business disruption. The ROI is driven by the need to replace the legacy application (eg the risk of its failure, its escalating maintenance costs, and constraints on the availability of the skilled resources necessary to support and enhance it).

♦ Enabling business initiatives that cross-functional or organisational boundaries. Services could be utilised to deploy IT solutions for new business initiatives that extend business processes beyond organisational boundaries or that embody cross-functional business requirements such as presenting a consolidated customer view across multiple product lines. The ROI is driven by the benefit of the business initiative including reductions in waste and inefficiencies and increases in the speed of processing.

♦ Establishing an enterprise portal. Services are an ideal way to create an enterprise portal and provide access to information from multiple legacy systems either internally or, extending outside the organisation, to customers and suppliers. The ROI is driven by the benefits delivered by the portal and reduction in costs in following a Services approach as an alternative to a ‘traditional’ information integration approach to providing content and functionality within the portal.

♦ Prolonging the life of a legacy application. Services can be deployed to add to, integrate with or share the functionality or data within a legacy application. Thus the replacement of the legacy application can be deferred. The ROI is justified by the cost avoidance of not having to acquire (or build) and implement a new system.

These scenarios can appear to be tactical in nature, however, with the right vision, initiatives like these can provide the foundation for a strategic enterprise-wide SOA implementation. For example, by thinking in advance about the future reuse of the Services being developed and adopting the appropriate governance disciplines from the beginning. The ‘big picture; vision for an SOA platform is nicely represented by SUN Microsystems in Figure 1.



4. SOA in practice

4.1 Case study

In 2005-6, Renewtek was engaged by a major aerospace manufacturer as their service delivery partner to integrate a new Manufacturing Execution System (MES) to PeopleSoft (HR), an old custom developed ERP system and an engineering design repository together with a number of other smaller-scale in-house developed applications.

The business driver was the expansion of manufacturing capabilities necessary for participation in a global manufacturing project for a new aircraft. The objective was to enable the integration of business applications and to streamline processes within a flexible architecture that reduced the ongoing cost of maintaining the integrated solution.

In consultation with their client’s IT management, Renewtek advised that SOA would provide a better more flexible approach than existing point-to-point integration solutions. The aim was to reduce the number of contact points for managing the integrated solution so that existing applications could be better used and re-used, making IT more responsive to the business overall.

BEA WebLogic was chosen because with its service oriented methodology, WebLogic applies an easy-to-use, standards-based approach to connecting existing IT solutions to produce a set of shared Services. By delivering these



Services independent from the underlying infrastructure, Renewtek ensured that the resultant integrated solution provided information access via real-world applications to the business’s internal and external stakeholders.

Renewtek delivered significant short- and long-term benefits for this major aerospace manufacturer:

♦ The ability for the business to globally expand its manufacturing capabilities while fully supported by integrated IT solutions.

♦ Reduced ongoing development cost.

♦ A robust and highly available systems environment able to sustain failure events without compromising the integrity of the integrated solution.

♦ A simple but powerful approach to ensuring the security of integrated solutions.

♦ A platform to enable further integration within its supply chain

SOA is not hard to implement. With appropriate thought, design and infrastructure, using proven best practices in architecture, design and development, Renewtek’s pragmatic approach and the application of agile techniques saw this delivered in a few months.

4.2 Delivering on the promise

Anecdotally, there are three main barriers for an organisation contemplating an SOA initiative: the timeframe is not imperative, the need for business justification and a lack of skills. Early in this paper, the difficulties with quantification of business benefits were discussed together with some real-world scenarios where an SOA ROI could be substantiated.

The skills requirement can be addressed in a number of ways. For example, targeted recruitment or engaging external expertise to guide the organisation in its process of adoption.

Based on Renewtek client engagement experiences we can also identify some general principles that will be of benefit to most SOA implementations:

♦ Take a strategic view but also be pragmatic about what is achievable.

♦ Establish the vision of a scalable, enterprise-wide SOA implementation and maintain that vision.

♦ Start with realistic projects that have a clear business imperative and strong business involvement.

♦ Deliver value quickly in short iterations.

♦ Adopt appropriate SOA governance principles from the beginning.



♦ Ensure that Service Descriptions and Service Directory capabilities are well defined and that predetermined standards and practices are implemented with along the way.

♦ Anticipate the future reuse of the Services being developed.

♦ Leverage existing tools and infrastructure.

♦ Don’t ‘reinvent the wheel’, adopt and use best practices.

What we say is: “think big, start small, scale fast”.

5. Conclusion

Many technologies and methodologies have failed to gain significant traction because they did not clearly support business objectives. SOA differs in this way because:

♦ It is entirely consistent with what business demands of IT.

♦ It aligns IT solutions with business processes.

SOA represents the evolution of best IT practices. It is the architecture that will enable highly integrated and dynamic solutions that are aligned with business processes and responsive to business demands.

The message is clear: SOA is the way.



6. Information

6.1 ABOUT THE AUTHORS Renewtek Associate Dr Brett L Scarlett is a Business Consultant and Information Technology project director, commercial IT vendor-contract manager, strategist and advisor with about 20 years experience in IT and management consulting. His client engagement experience covers a range of industries: Internet and Applications Service Providers, Telecommunications, Utilities, Transportation, Financial Services, Government and Media. And his project experience includes: vendor contract management (outsourced services), strategic consulting, business planning and analysis, architecting technology and application solutions, process redesign, systems integration, software and production systems support and project management.

Jerry Shea is Renewtek's CTO and is a seasoned IT professional with extensive experience in architecting and building enterprise solutions and products. Jerry has held senior technology roles in consulting and software development organisations in Europe, Asia and Australia, where he has successfully delivered major eCommerce and enterprise application projects. He has undertaken development, consulting and pre-sales work in Australia, Asia and the UK with DST, AXA, British Telecom and BEA Systems to name but a few. He holds a B.Sc.(Hons) in Computer Science from Southampton University and is SFA Securities Representative from The Securities Institute of London.

6.2 ABOUT RENEWTEK Renewtek is a technical consultancy and project delivery specialist with a focus on the provision of hard-core technical skills for the delivery of business critical solutions. Renewtek helps organisations minimise their business risk through the provision of common sense consulting with an in-depth understanding of how technology can best be utilised to achieve business outcomes. Renewtek’s extensive experience can mitigate the business challenges associated with implementing new technology; upgrading existing technology assets; and the integration of disparate technologies. www.renewtek.com.


1

Renewtek Pty Ltd ABN 11 110 232 623 17/120 Collins Street Melbourne VIC 3000 Australia T 61 3 9670 7790 F 61 3 9670 6663 8/58 Pitt Street, Sydney NSW 2000 Australia T 61 2 9252 4999 F 61 2 9252 4139 [email protected] www.renewtek.com

Date post:	28-Nov-2014
Category:	Technology
Upload:	aamir97
View:	565 times
Download:	2 times