1. You’ve Built The Pieces, Now Integrate Your Enterprise! Mid-Atlantic Regional Conference January 17, 2003 Patty Gertz, Princeton University Patty@princeton.edu Copyright Patricia Gertz, 2003. This work is the intellectual property of the author. Permission is granted for this material to be shared for non-commercial, educational purposes, provided that this copyright appears on the reproduced materials and notice is given that the copying is by permission of the author. To disseminate otherwise or to republish requires written permission from the author.

2. Enterprise Application Integration “Making independently designed application systems work together.” Gartner

4. Why do we need this?  Applications are changing – not all in-house developed, many are purchased.  Customers are changing – larger, broader constituencies.  Services are changing – self-service, access through the web.  Web enablement vs. web development vs. web integration vs. web services.  Gartner says 35% of the IT budget in new projects will go to integration. We need to manage this.

5. Goals  To reconcile differences in data.  To coordinate execution of logical processes that span applications.  To reuse parts of existing applications as components of new ones.  To be agile.

6. What do we gain?  A more flexible approach to automating business processes will make us more responsive.  Typically interfaces are point to point, separately designed and built.  This has resulted in a new version of the spaghetti diagrams we saw in the past.

7. New World Spaghetti Code

8. Integration Approaches  Technical – middleware, messaging, file transfer  Data – db replication, directory services, common data definitions and storage  Business Process – think in terms of logical business processes, even when they cross the line of a particular application  User Interface – the web and portals can unify the enterprise. Layering apps so you control the presentation.

9. Addressing IS Heterogeneity n Three approaches: – Rip out and replace – Wrap or re-engineer – Leave and layer

10. Rip and Replace n “Bulldoze the slums.” n Replacing with a new set of consistent applications (ex. ERPs) n Easy interoperability, reuse, common data. n Business reality often makes this not possible.

11. Wrap or Re-engineer n Wrapping masks the problem of heterogeneity. n Re-engineering changes the apps to conform to new standards. n Technically hard, good for new, component-based apps. n Service Oriented Architecture – Web services, WSDL, XML

12. Leave and Layer n City Planning vs. Architecture n Leave underlying systems alone, and understand change will always happen in that layer n Use file transfer, messaging, shared databases, for information exchange.

13. Architecting an Integrated Enterprise  Enterprise architecture describes the underlying distributed computing infrastructure.  It helps us manage the impacts of changes. Applications must deal with changes in business processes from above, and changes in technology from below.  Equally good for new development and integration.  Service Oriented Architecture

14. Qualities of a Good Architecture  Adapt to change  Flexible  Good performance  Scalability  Security  Manageability  Reliability  Portability  No vendor lock-in

15. W hat’s Different About Web Applications?  State  Authentication / Authorization  Scalability and Performance - Pooling and sharing of resources  Commit / Rollback, even with multiple targets

16. Application Layers : Standard 3-Tier

18. J2EE and Component Based Architecture What Services does it offer?  Standardized modular components/reuse  Connection sharing - multithreading  Static and dynamic web pages  Messaging  Database Resource pooling  Platform independence

19. Getting Started  People must be in a separate group – can’t be associated with a specific project.  Management Support – someone has to be convinced it’s worth extra resources.  Global view – step back and architect.  Skills – Object orientation, components, J2EE or.Net  The sooner you get started, the less you have to undo.