Enterprise_Application_Integration_(EAI)

Lecture 1 Introduction to Enterprise Application Integration (EAI) Outline • Enterprise application integration (EAI) and challenges • Purpose of EAI – Portal Integration – Entity Integration – Process Integration – B2B Integration 2 Enterprise applications • Software which provides business logic support functionality for an enterprise, typically in commercial organizations – Aims to improve the enterprise's productivity and efficiency. – Examples: • online shopping and online payment processing, interactive product catalogue, automated billing systems, security, content management, CRM, ERP, Business Intelligence, HR Management, Manufacturing, EAI, Enterprise Forms Automation 3 • Hundreds of applications in the enterprise – In-house – third-party vendors – run on multiple computers – run on multiple platforms – geographically dispersed – Run by business partners or customers. – Legacy Systems 4 The different applications are used to solve very narrow problems within departments Legacy System • Old technology, computer system, or application program that continues to be used – it still functions for the users' needs – widely used for banking, manufacturing and financial control functions in large corporations – Not likely to be replaced in the near future • New hardware is no longer available • Original source code has been lost. • Support no longer be found 5 Enterprise Application Integration • Connect the applications in the enterprise to allow unrestricted sharing of data and business processes among any connected applications or data structures 6 Why Enterprise Integration? • One may build a new system or component by implementing it from ground-up, so why enterprise integration? Cost factor.  Legacy systems.  Spreading business functions across multiple applications achieves flexibility Business requirements (and thus the related business processes) are changing rapidly. 7 Integration Challenges • Heterogeneous applications – Different programming languages, run on different OS, use different data format, etc • Application may change over time – if one system changes, all other systems may be affected 8 • Networks are unreliable – delays or interruptions • Networks are slow – Sending data across a network is multiple orders of magnitude slower than making a local method call. 9 Order Processing Process 11 Browser Order Send Invoice Receive Payment Delivery Order Entry System Warehouse System Finance System Inventory System Static Web Server Order Processing Customer Service Representative Send Order Customer Purpose of Integration • Portal Integration • Entity Integration • Process Integration • B2B Integration 12 Portal Integration: motivation • Users may have to access more than one system to answer a specific question or to perform a single business function • Information portals aggregate information from multiple sources into a single display to avoid having the user access multiple systems for information. 13 Order Tracking 14 Browser Order Send Invoice Receive Payment Delivery Order Entry System Warehouse System Finance System Inventory System Static Web Server Order Processing Customer Service Portal Customer Service RepresentativeCheck product availability, check order status, cancel order, change of address Customer Use of portals • A portal gives the customer service representative a unified view of the various records for a customer • Helpful in providing efficient and effective service to the customer • Aggregate information only for end user but not for applications – Simple to implement 15 Variation of portals • Functionality and complexity – Display only – Simple Processing – Single Application Interaction – Cross pane interactivity 16 Display only • Simply displays data in different areas of the screen (a rectangle area called pane) • Allows the user to view information retrieved from multiple applications on a single screen 17 Simple preprocessing • Add simple rules that help the user make decisions – E.g. if the billing system reports that a customer payment is overdue, the portal would list this as an exception in bold red letters at the top of the screen 18 Single application interaction • Users may issue commands to an application • No interaction between applications 19 Cross pane interactivity • Information displayed in one pane depends on a user selection in another pane • Select a customer from a list of customers retrieved from CRM --> show his payment history 20 Entity Integration: Motivation • Data are stored redundantly across different applications • For example, an employee entity is usually defined in human resource management system (HRMS) applications, in payroll applications, and in benefits applications, as well as in other systems. – Each system defines its own view of an employee. – if you are building an employee self-service portal, you need to have a complete view of what constitutes an employee and not just the bits and pieces. 21 Order Processing Process 22 Customer Data Customer Browser Order Send Invoice Receive Payment Delivery Order Entry System Warehouse System Finance System Inventory System Static Web Server Order Processing • Order entry system (for contact) • Finance system (for billing) • Warehouse system (for delivery) Entity Aggregation • Provides a logical representation of unified data entities across multiple data stores. • Applications can interact with this representation as if it were a single data source • Simplifies the development of applications that need to access data across multiple data stores 23 Schema Reconciliation • The representation of an entity within the different applications may not be the same – Different repositories can hold different schemas for the same entity • The Entity Aggregation layer must harmonize the subtle differences between these schemas – define a unified schema for all entities which represents a logical consolidation of all the views – effect transformations between each repository’s schema and the unified schema 24 Schema mapping 25 Customer Self Service Enterprise portal Other systems Issues to handle • Same data is represented with different identifier – "order" and "purchase order" • Semantic dissonance – Data that appears to be the same may not necessarily mean the same thing – E.g. inventory system: price, catalog: price after discount • Inconsistent data – What if the price in the catalog and inventory system is not the same? 26 Process Integration • Focuses on the coordination of interactions between multiple systems which may involve multiple disparate applications – Different tasks may be performed by different users – Different tasks may read or write data from different sources – The tasks may be executed sequentially or in parallel • Allow changes of the business process without affect the underlying business applications 27 Order Processing Process 28 Product Data Order Tracking Data Customer Data Browser Order Send Invoice Receive Payment Delivery Order Entry System Warehouse System Finance System Inventory System Static Web Server Order Processing Delivery before payment Browse Catalog Send Invoice Receive Payment Delivery Order Processing Browse Catalog Send Invoice Receive Payment Delivery Order Processing Premium customer Send Invoice Receive Payment Delivery Normal customer OR Issues to handle • Complex business functions can often take days or weeks to complete. – Asynchronous/synchronous interaction • Handle multiple concurrent executions of a process • What if one of the application within a process fails? – Roll back should be supported to return to a consistent state 30 Business-to-Business Integration • Business functions may be available from outside suppliers or business partners, e.g. – The shipping company may provide a service for customers to compute shipping cost or track shipments. – A business may use an outside provider to compute sales tax rates – A customer may contact a retailer to inquire on the price and the availability of an item. In response, the retailer may ask the supplier for the status of an expected shipment that contains the out-of-stock item. 31 32 Handle order Ship product Receive order Supplier B B2B Integration Browser Catalog Send Invoice Receive Payment Delivery Order Processing Quote Reply Pick up Quote request Order Processing Shipping Agent Handle order Order part Order part Ship product Receive order Supplier A Deliver Compute Charge References • Integration Pattern – http://msdn.microsoft.com/en-us/library/ms978729.aspx – Chapter 1 and Chapter 3 • Enterprise Application Integration: A Wiley Tech Brief – http://library.polyu.edu.hk/search~S6/?searchtype=t&sear charg=Enterprise+Application+Integration%3A+A+Wiley+T ech – Chapter 1 33