Legacy Migration and Modernization Leveraging the Value of Your Existing Architecture
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Legacy Migration and Modernization: Leveraging the Value of Your Existing Applications in a Modern Enterprise Architecture Bob Mastro – Vice President Health and Human Services NYC Technology Forum, November 1, 2007 Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 1 Leveraging the value of your existing applications… Enterprise Architecture Model-Driven Architecture Modernization Strategy & tactics OMG ADM efforts Service-Oriented Architecture Existing Software Unisys ADM Vision and practice ArchitectureDriven Modernization Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 2 The field is rarely green The Assumption The Reality Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 3 Knowledge-Based Modernization Critical Business Knowledge is locked inside three sources of knowledge Applications (most accurate) Documentation Subject Matter Experts Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 4 The “legacy” application: an asset and a liability The moment an application goes into production, it becomes “legacy” It’s an asset! – – – – It’s a liability! Functional Customized Well-tuned Supports mission critical operations – Provides a competitive edge – – – – – Uses old technology Requires hard-to-find skills Lacks documentation Hard to maintain Resists change, integration, and replacement “You got to ac-cent-tchu-ate the positive, E-lim-i-nate the negative!” — Song lyric by Johnny Mercer, 1944 Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 5 Reduce the negatives through modernization Architectural “big picture” view • Align software assets with enterprise architecture vision: Architecture-Driven Modernization (ADM) Ongoing management process view • Disciplined, strategic planning for old and new applications: Application Portfolio Management (APM) Cost-benefit view • Apply across all software assets: Application Portfolio Analysis (APA) “Home Improvement” view • Never-ending • Plan to spend money Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 6 Architecture-Driven Modernization (ADM) • The process of understanding & evolving existing software assets within an architectural framework • The mirror image of Model-Driven Architecture (MDA) Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 7 ADM & MDA • Modernization begins with the extraction and abstraction of knowledge from the existing application • How far to abstract? It depends on the type of modernization A D M Extract, Abstract, and Model Knowledge Computation Independent Viewpoint domain Platform Independent Viewpoint M D A design Platform Specific Viewpoint code Understand Existing Application “As is” & Evolve New or Renewed Application “To be” Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 8 EM (a.k.a. ADM) covers a broad scope Enterprise Modernization (EM) is a discipline concerned with • evolving existing systems to meet future needs • identification of the gap between existing system and enterprise’s current requirements • preserving investments in existing systems (including proven business logic and expertise of current staff) • understanding existing software and other IT assets Architecture-Driven Modernization (ADM) is the process of understanding & evolving existing software assets for purposes of: • • • • • • application portfolio management code improvement programming language translation integration platform migration data migration • • • • • • consolidation data warehousing reuse package selection service-oriented architecture model-driven architectures — Object Management Group ADM Task Force 3D-VE uses the terms “ADM”, “Enterprise Modernization”, “Enterprise Asset Modernization”, “Legacy Modernization” and “IT Modernization” as synonyms Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 9 Six modernization styles Style Definition Results 1. Discover Mine knowledge and abstract it to the right level As-Is model at the appropriate level of abstraction 2. Refactor Improve application without changing language or platform Streamlined application with no dead code, no database redundancy, etc. 3. Translate Highly automated language-to- Application in the target language language translation replicates functionality 4. Wrap Encapsulate cohesive functionality in a SOA harness Portions of original application turned into components providing services 5. Replace Replace applications with new custom or packaged solutions New, modern components that provide services that replace the legacy system 6. Orchestrate Orchestrate wrapped and newly replaced services The composite solution using existing and new services Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 10 Unisys ADM framework MODERNIZATION MODERNIZATION BUILDING BUILDING BLOCKSBLOCKS Discover & Understand Mine Refactor Translate Wrap Replace Orchestrate Knowledge Business processes PERSPECTIVE Business Business info reqs Business rules Application Logical data model Application boundaries Application logic Realization Physical data model Interface definitions Execution flows Implementation Program logic “AS IS” APPLICATION “TO BE” APPLICATION Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 11 Abstracting knowledge to business rules model level Business Rules Business Vocabulary Spaghetti code, hiding business knowledge “Your Application” OMG SBVR Standard [3] Legacy asset preservation Business model optimization Forward engineering Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 12 Mining knowledge from the outside in Business rule Error Message Report Field • Start with “boundary elements” visible from the outside of the application, and follow paths through the code • Tools are essential, but... First law of knowledge mining “Your Application” Green Screen Field "Only a computer can analyze vast quantities of code, but only a human being can recognize what has business value." Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 13 The modernization journey… …begins with mining of knowledge from existing applications… …and heads towards Service Oriented Architecture (SOA) SOA? SOA what! Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 14 SOA enablement: Wrap and reuse Service Consumer (Client) Request message Result message Service interface Standard & visible Service wrapping Back-end systems (Black box) Implementation is hidden Eligibility Call Multiple client Web selfCase applications service management Determination Center sharing services messages messages messages Conceptual “service bus” based on messaging messages Reusable services Open case messages Address change Calculate budget Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 15 SOA: avoiding spaghetti on top of spaghetti Source: Gartner Group Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 16 Turning spaghetti code into services “Pasta Transformation” Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 17 SOA enables composite applications Composite applications represent a design pattern that combines current applications, new application logic and application integration to provide new functionality Composite Application Composite Service Service Service Service Java EE Component Composite Service Service Service Composite Service Service COBOL System Service Service Service .Net Component SOA provides a way to assemble composite applications in a productive and flexible manner Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 18 Part 2: The Unisys vision for ArchitectureDriven Modernization: Theory into practice Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 19 Knowledge-Based Modernization New Business Requirements / Optimization Criteria As-Is Business Model (Vocabulary + Rules + Processes) Upgrading & Optimization Business Domain To-Be Business Model (Vocabulary + Rules + Processes) Mine To-Be SOA Application Model (Data + Choreography + Orchestration) Generate Existing Solution Forward Engineering As-Is Application Model (Data + Logic + Flows) Reversed Engineering ADM Target Solution IT Domain Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 20 Applications Wrapping – SOA • Using Unisys tools from partners Relativity Technologies and KDM Analytics • Document your legacy assets – Expose, navigate & provide a flow of the application logic – Diagram all input and outputs – Excavate architecture – identify deficiencies (unnecessary dependencies, lack of structure, etc.) – Show database accesses & schema – Discover & define application rules • Complete inventory of all legacy assets • Streamline applications – Identify and eliminate dead code and code defects – Remove unnecessary dependencies • Transform applications – Break down application into modules – Transform modules into services – Replace presentation with HTML, Java Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 21 Example: linking rules to code business vocabulary and rules implementations in the code Unisys 3D-VE Rules Modeler Technology is embedded in KM Links between business vocabulary and rules and their implementations in the code Code implementation discovered by 3rd-party mining tool Inventory contains references to the source code Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 22 Unisys KMA for Business Rules • Discover intellectual property using Relativity – Reverse engineering of application code – Mines ‘programmatic’ rules • Create Business Rules Model using Unisys Rules Modeler • Maintain traceability between business rules and program rules • Enables a model-driven approach to forward engineering – Enables application re-partitioning from the business process perspective – Application can be restructured to optimize performance and maintenance – New requirements can be added at the “to-be” modeling stage – Can take advantage of model-driven code generation capabilities – Enables ‘gap analysis’ for replacement with ‘off-the-shelf’ application Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 23 Building a modernization strategy on Unisys ADM building blocks •The ADM approach for a given application may involve several ADM building blocks. •Discovery of existing application knowledge is required for all scenarios… … but extent of discovery (“knowledge mining”) and level of abstraction varies by scenario ADM Building Block Discover Refactor Your Application Portfolio App 1 App 2 App 3 App 4 App 5 √ √ √ √ √ Translate Wrap √ √ √ √ √ √ √ Replace Orchestrate √ √ √ √ The decision of what to do for each piece depends as much as on business goals, migration logistics, and economics as on the state of the technology Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 24 Summary • Modernization strategy: Modernization strategy – Let enterprise architecture drive your strategy – Apply across your entire software portfolio Modernization tactics • Modernization tactics: – Apply a combination of modernization building blocks: Refactor, translate, wrap, replace, orchestrate – Mine knowledge and abstract to appropriate level Modernization journey • Modernization journey: – Begin with understanding existing software – Head in the direction of Service Oriented Architecture – Unisys can help, using its expertise, methodology and partnerships Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 25 Questions? For further information contact: [email protected] Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 26 Legacy Migration and Modernization - NYC Technology Forum 11/01/2007 Page 27