Legacy isn’t planned – it just happens. All organizations must at some point address their legacy IT. For many public sector organizations, the challenges of operating with aging systems and applications are all too familiar. The longer we postpone the inevitable task of renewing or replacing legacy IT, the worse the problem will become. Legacy systems are hard to extend and difficult to adapt as new services are brought online and as business functions change. Legacy environments are expensive and time-consuming to maintain; and brittle code makes it hard to modify one area of the system without impacting other areas unnecessarily. Making even simple changes to business processes can mean rework in multiple systems. Legacy applications are often

single-purposed and reside in silos, making it difficult to share data and interoperate with other systems throughout the enterprise. All in all, it’s a costly, time consuming and service-limiting problem that all organizations need to address in order to move forward.

Evaluating Legacy Modernization Options

Two generally accepted approaches are ‘Legacy Migration’ and ‘Legacy Renewal’. Legacy migration includes replacing ‘green screens’ with modern, web-based UIs built on top of the legacy architecture. It also provides the option of moving legacy applications off the mainframe and onto newer hardware using virtualization techniques. The downside of using

the migration approach is that it’s only a temporary solution. It’s a cosmetic, skin-deep approach that fails to address the underlying issues that make more fundamental renewal of legacy systems the only sustainable solution for the longer term.

Successfully overcoming the challenges raised by legacy IT therefore requires utilizing the “Legacy Renewal” approach. Legacy renewal leverages new application architectures to address the underlying problems of poor maintainability, poor scalability and lack of flexibility. When building out an enterprise class architecture capable of supporting multiple systems and lines of business, service oriented architecture (SOA) is considered an industry best practice.

Legacy Renewal through Service Decomposition: A guide for Public Service Organizations

Accenture Software

SOA has received considerable attention over the years and next to “cloud computing” is perhaps one of the most over-used and over-marketed terms in our industry. Contrary to what many vendors would have you believe, SOA is not a single product, technology or standard. Instead, it’s an overall approach to architecting enterprise applications in a way that provides them with shared access to core pieces of functionality.

SOA allows organizations to incorporate commercial off-the-shelf (COTS) software into their overall solution, thereby providing the enterprise with best-of-class functionality, including: business process management, business rules management, enterprise content management, security, etc.

Exposing this functionality as a set of shared web services allows these core capabilities to be shared across the enterprise, thereby increasing utilization and improving return on investment. Application silos are

now a thing of the past. SOA drives consistency across all systems. Whether changing a business rule, a workflow, or a security policy, changes need to be made once and in only one place.

SOA is portable. It allows the latest technologies to be incorporated regardless of the underlying hardware, operating system, or programming language. SOA’s flexibility and agility means new technologies can be introduced easily and application components can be added without impacting other areas of the system.

What’s more, SOA fosters the externalization of business process workflows. Because business process logic is no longer embedded within the application code, SOA allows non-technical users to easily make changes without programmer intervention. This creates a more responsive and agile business, able to adapt to new business demands without having to compete for limited development resources.

Phased Renewal vs. the Big Bang Approach

The benefits of moving to a SOA-based solution are clear. Now is the time to upgrade. By failing to act, an organization not only faces the risk of technical obsolescence but also a dwindling supply of people who are capable of supporting their existing environment. At the other extreme is the option of replacing everything in one shot. But this ‘rip and replace’ approach presents clear risks of major disruption to the business. For public sector organizations in particular, this is likely to be unpalatable, as continuity is essential in the provision of many, if not all, public sector services. Accenture believes that a gradual approach to legacy renewal, based on service decomposition, offers an ideal balance between the two extremes – doing nothing and the big-bang approach.

As shown in Figure 2, legacy renewal involves the transition from a legacy environment to a modern SOA architecture.

Legacy-based applications typically manifest these problems:

• Business processes and rules are tightly embedded within the application code.

• Contain point-to-point wirings and “spaghetti code” that is brittle and difficult to change.

• Business changes require a full software development lifecycle (SDLC) to implement.

Services

CoreFunctionality

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Figure 1: SOA Concepts and Benefits

Service decomposition facilitates a transition to a SOA architected environment, shown in Figure 2:

• The core capabilities of the system are provided by best-of-class COTS products.

• The SOA architecture ties everything together in a standardized fashion and enables sharing of the underlying functionality via an enterprise service bus (ESB).

• The SOA architecture serves as a platform on top of which, the business specific components, including business processes, services, and rules are built.

• Finally, composite applications are now ‘lightweight’. When an application reaches the end of its useful life, retiring them simply requires discarding the user interfaces and the small amount of business logic specific to that application. Everything else can be re-used.

Service Decomposition

Service Decomposition is a process or approach that can be used to help an organization gradually transition from legacy to a modern enterprise architecture without incurring the risk and expense of the “rip and replace” option. Service decomposition essentially involves identifying candidate services for migration and the order in which those services will be built. Newly developed services are deployed to the newly implemented SOA. Legacy functionality, that continues to provide utility, can be ‘wrapped’ with a service layer and ‘plugged’ into the new SOA environment. By breaking the dependency on the underlying architecture, an organization can utilize a phased approach to service migration,

thereby considerably lowering the risk of business disruption.

SIF (conceptually depicted in figure 3) is an Accenture methodology specifically designed to help organizations identify candidate services for decomposition and ultimately, from that analysis, create a roadmap for service migration. SIF uses a hybrid process for service identification that combines both a top-down and a bottom-up approach.

Top-down Approach (process-centric)

The top-down approach uses business strategy to identify the core competencies of the business and the business processes that are required to support them. It’s important to note that not all processes are candidates for automation. An ROI assessment governs the choice, so that only those that deliver the greatest

Rules App Server

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Figure 2: Legacy renewal through service decomposition

Figure 3: Accenture’s Service Identification Framework

Service Identification Framework

Service Identification Framework (SIF)

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value are automated. Once process identification and selection is complete, those processes are decomposed into their constituent individual tasks, which then become the service candidates.

Bottom-up Approach (service-centric)

The bottom-up assessment involves looking at the organization’s current enterprise architecture, i.e. its technical architecture (infrastructure), information architecture (data) and application architecture. By analyzing existing systems, current capabilities can be identified. Are there current legacy capabilities that work well and that continue to provide essential functionality, or is there legacy functionality that is “good enough” and that can be leveraged temporarily as part of a phased migration strategy? Are there recent purchases, e.g. a data warehouse or enterprise content management system that provide core capabilities that can be re-used? These capabilities are then decomposed and used to identify service candidates.

Hybrid approach By combining a top-down approach with a bottom-up approach, a gap analysis can be conducted in terms of the services required and the capabilities provided. This is then used to create a service “roadmap” that catalogs the necessary services and provides a detailed plan for their implementation.

Conclusion

Public sector organizations are increasingly faced with the challenge of selecting an appropriate approach to moving to a more flexible, agile and responsive platform. For most, SOA is the architecture of choice, but making that transition is often fraught with uncertainty. By enabling a phased approach to legacy renewal, service decomposition can help manage the risks that inevitably arise from such a transition. And lastly, selecting the appropriate partner and tools for this journey is crucial. An experienced partner, a field tested approach, and a pre-configured technology solution can greatly improve the probability of a timely and successful outcome.

For more information

please contact: David Bentley +1 512 799 4834 david.b.bentley.jr@accenture.com

About Accenture Accenture is a global management consulting, technology services and outsourcing company, with more than 246,000 people serving clients in more than 120 countries. Combining unparalleled experience, comprehensive capabilities across all industries and business functions, and extensive research on the world’s most successful companies, Accenture collaborates with clients to help them become high-performance businesses and governments. The company generated net revenues of US$25.5 billion for the fiscal year ended August 31, 2011. Its home page is www.accenture.com.

About Accenture Software Accenture Software combines deep technology acumen with industry knowledge to develop differentiated software products. It offers innovative software-based solutions to enable organizations to meet their business goals and achieve high performance. Its home page is www.accenture.com/software. For Health & Public Service software, its home page is www.accenture.com/publicservicesoftware.

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Accenture Public Service Platform – SOA ‘out of the box’

The Accenture Public Service Platform (APSP) removes the confusion and guesswork around SOA implementations by providing a pre-built, pre-tested architecture that easily connects custom developed applications and leading third party COTS products.

APSP helps organizations build for tomorrow while protecting their current application investment. Its multi-layered design provides public organizations with the breadth and flexibility they need to address both their legacy renewal and enterprise integration needs.

Learn more at www.accenture.com/APSP.