1 Enterprise IT [Πληροφοριακές Τεχνολογίες της Επιχείρησης] Lecture 1, 2 and 3: Enterprise Systems Architecture Univ. of the Aegean Financial and Management Engineering Dpt Petros KAVASSALIS

2 What you will learn in this course A set of fundamental concepts for understanding basic Enterprise Information Technologies A set of fundamental concepts for understanding basic Enterprise Information Technologies  Enterprise Software Applications  Enterprise Architecture Integration (EAI) Strategies for integrating applications using standard technologies Strategies for integrating applications using standard technologies  XML  Web Services Familiarization with concepts such as: Familiarization with concepts such as:  Interoperability  e-business  e-government 2.0  Best practices and techniques for building and migrating enterprise IT infrastructure to a Service-oriented Architecture

3 Who am I? PhD in Economics and Management (Univ. Paris Dauphine & Ecole polytechnique) PhD in Economics and Management (Univ. Paris Dauphine & Ecole polytechnique) Research experience Research experience  Ecole polytechnique, Paris  MIT Center of Technology Policy and Industrial Development, MIT CTPID (MIT Internet Telecommunications Convergence Consortium) Current positions Current positions  Univ. of the Aegean (FME): Assoc. Professor  RACTI: Director of ATLANTIS Group

4 Communication tools Course web site: see FME web site Course web site: see FME web site

5 Students evaluation Class Participation (20%) Class Participation (20%)+ Assignments (20%) Assignments (20%)+ Final Exam (60%) Final Exam (60%)

My expectations [I copy a colleague I respect a lot…] Enterprise IT course requires consistent effort and active participation (I want from my students to avoid missing lectures) Enterprise IT course requires consistent effort and active participation (I want from my students to avoid missing lectures) Important suggestion: Please take extensive notes in the class Important suggestion: Please take extensive notes in the class I'm not a formal person and will be as accessible as I can to all of you through and physically – my official office hours are proposed as Friday, 12:00 – 15:00h I'm not a formal person and will be as accessible as I can to all of you through and physically – my official office hours are proposed as Friday, 12:00 – 15:00h But my informality doesn't mean I'm casual about what goes on in my class… But my informality doesn't mean I'm casual about what goes on in my class… 6

Enterprise Information Systems (1) Information technology is the hardware and software a business uses to achieve its objectives Information technology is the hardware and software a business uses to achieve its objectives EnterpriseIS (according to Wikipedia) EnterpriseIS (according to Wikipedia)  An Enterprise Information System is generally any kind of computing system that is of "enterprise class". This means typically offering high quality of service, dealing with large volumes of data and capable of supporting some large organization ("an enterprise").  Enterprise Information Systems provide a technology platform that enables organizations to integrate and coordinate their business processes. They provide a single system that is central to the organization and ensure that information can be shared across all functional levels and management hierarchies. Enterprise systems are invaluable in eliminating the problem of information fragmentation caused by multiple information systems in an organization, by creating a standard data structure.  A typical Enterprise Information System would be housed in one or more Data centers, run Enterprise software, and could include applications that typically cross organizational borders such as Content management systems. 7

Enterprise Information Systems (2) Enterprise information systems (EIS) has become increasingly popular over the last 20 years because they integrates and extend business processes across the boundaries of business functions and corporate walls, as well as country border lines. Enterprise information systems (EIS) has become increasingly popular over the last 20 years because they integrates and extend business processes across the boundaries of business functions and corporate walls, as well as country border lines. EIS have to deal with three basic realities: EIS have to deal with three basic realities:  Data: streams of raw facts representing events and occurrences  Information: data shaped into a meaningful and useful form  Knowledge: application of data and information (examples: modeling, simulations etc) to answer "how" questions o “Knowledge is only relevant in the context of changing conditions when someone who needs to make a decision can synthesize ‘information’ INTO ‘knowledge’ given the current change situation” ( 8

9 Enterprise Systems Architectures Enterprise System Architectures (ESA) are composed of IS Enterprise System Architectures (ESA) are composed of IS  Different from software systems in the area of “embedded computing” Enterprise System Architectures integrate business architecture and IS architecture (convergence of business and technology) Enterprise System Architectures integrate business architecture and IS architecture (convergence of business and technology) ESA makes possible ESA makes possible  The re-usability of business and technology infrastructure  The leverage of a knowledge base of market and enterprise data, content and documents, operations methods and their status information etc. … to provide agility and therefore competitive advantage … to provide agility and therefore competitive advantage [more: see M. Weske: Business Process Management: Concepts, Languages, Architectures, Springer, 2007, chapter 2] [more: see M. Weske: Business Process Management: Concepts, Languages, Architectures, Springer, 2007, chapter 2]

10 Enterprise Architectures’ evolution paths: early system architectures OS Application db OS Application DBMS db OS Application DBMS GUI HOT! Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007

11 Enterprise Architectures’ evolution paths: multiple enterprise applications Due to the massive introductions of PCs in the business space and, with lowering cost of computer hardware, more applications were developed. Example: Due to the massive introductions of PCs in the business space and, with lowering cost of computer hardware, more applications were developed. Example:  Software system for HRM  Software system for purchase order management (POM)  Software system for production planning (PP)  etc.  Each of these applications hosted its local data, in a database system o Please design what is written above… But these application systems hosted related data But these application systems hosted related data  One logical data object (let’ say a customer mail address) was stored in different data stores managed by different application systems  When it was to change something…  Babel!  One has to definitively deal with data dependencies

12 Enterprise Architectures’ evolution paths: ERPs An ERP stores data in one centralized database. A set of application modules provides the desired functionality, e.g HR, financial, operational etc. An ERP stores data in one centralized database. A set of application modules provides the desired functionality, e.g HR, financial, operational etc. ERPs are accessed by client applications; they access an application server that issues requests to a database server ERPs are accessed by client applications; they access an application server that issues requests to a database server db OS ERP Server Application DBMS Client 1 Client 2 Client n Client 3 A two-tier client-server architecture Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007

13 Enterprise Architectures’ evolution paths: SCM, CRMs… and ERPs New types of software entered the market New types of software entered the market  Supply Chain Management Systems (SCMs)  Customer Relationship Management Systems (CRMs) … developed by different vendors than ERPs … developed by different vendors than ERPs Result: heterogeneity again! Result: heterogeneity again! db OS CRM Application DBMS GUI db OS SCM Application DBMS GUI db OS ERP Application DBMS GUI Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007

Heterogeneity… i.e. siloed apps (manual integration versus middleware) Integrate manually… Integrate manually…  How does this happen? Or Middleware: Enterprise Application Integration System Or Middleware: Enterprise Application Integration System 14 Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007

What is Enterprise Application Integration? Enterprise Application Integration (EAI) is defined Enterprise Application Integration (EAI) is defined  As the use of software and computer systems architectural principles to integrate a set of enterprise computer applications (Wikipedia)  As the unrestricted sharing of data and business processes among any connected applications and data sources in the enterprise (Gartner) Different layers of integration Different layers of integration  Data Integration  Process Integration 15

Layers of Enterprise Application Integration (1) Data Integration Data Integration  Data integration works by providing homogenous data representations to a range of disparate data sources  Levels of data integration o Data types o Names of Attributes o Semantics of the Attributes  Let’s discuss un example [on the basis of the following slide] Process Integration Process Integration  In addition to data integration, the processes that the applications execute need to be integrated.  Process integration works by providing coordination between activities performed by different apps…  Through a common business process model that specifies the sequence of activities, roles related to activities, events and information movement between apps residing in the same, or co-operating enterprises 16

[Data Integration] from S. Madnick Course at MIT 17

[Process Integration] from S. Madnick Course at MIT 18

Layers of Enterprise Application Integration (2) (a layer down) (a layer down)  Provides data encryption and network connectivity (Internet Protocols and HTTP)  Messaging middleware (see below): asynchronous versus synchronous communication mode (a layer between data and process integration) API Integration (a layer between data and process integration) API Integration  Passes information between 2 systems (data, application business logic and rules can be used to maintain information flow consistency)  An API may describe the ways in which a particular task is performed. Example: Process Integration Layer API Integration Layer Data Integration Layer Transport Integration Layer XML

Enterprise Application Integration: Topologies Enterprise Application Integration also follows topologies! Enterprise Application Integration also follows topologies!  Different approaches to Enterprise Application Integration implementation  In all cases o Integration techniques are being used to bridge heterogeneous data formats and application processes and transform INCOMING MESSAGES received from an origination application received from an origination application to a format that the destination application can understand and utilize to a format that the destination application can understand and utilize o Integration techniques are linked to message brokering technologies, as for example MOM Message-Oriented Middleware (MOM) is an infrastructure that involves the passing of data between applications using a common communication channel that carries self-contained messages (Source: M. Papazoglou, e- Business, J. Wiley, 2006) Message-Oriented Middleware (MOM) is an infrastructure that involves the passing of data between applications using a common communication channel that carries self-contained messages (Source: M. Papazoglou, e- Business, J. Wiley, 2006) 20

[parenthesis: Messaging] Distributed systems and applications communicate by exchanging messages Distributed systems and applications communicate by exchanging messages Messaging enables high- speed, program-to-program communication with reliable delivery Messaging enables high- speed, program-to-program communication with reliable delivery Message passing between a pair of processes is supported by two message communication operations: send and receive, defined in terms of destinations and messages Message passing between a pair of processes is supported by two message communication operations: send and receive, defined in terms of destinations and messages 21 Source: M. Papazoglou, e-Business, 2006

22 EAI Topologies’ evolution paths: the enterprise application integration system (1) Point-to-point integration Point-to-point integration  Applications communicate by sending and receiving messages (MOM)  Middleware centralized component  Run-time guaranteed but problems with the complexity at the communication level Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007

EAI Topologies’ evolution paths: the enterprise application integration system (2) 23 Hub-and-spoke integration Hub-and-spoke integration  Centralized hub (application integration middleware), spokes (i.e. applications) which are not connected between them  Different type of messaging o Each message is sent to the application integration hub, thus the number of connections are reduced… o Message brokers(!): software that allows a user to define rules of communication between applications Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007 Implementing and changing communication structures is taken away from apps

Enterprise Application Integration through Workflow (1) Attention: Communication between apps structures, in all previous topologies, are embedded in rules the message broker hosts Attention: Communication between apps structures, in all previous topologies, are embedded in rules the message broker hosts  These rules are only managed by techies  A more explicit representation of the communication between apps on the basis of the process in which they contribute, is needed Workflow Management Workflow Management  Addresses the integration problem through Business Process Automation and from a user-centric point of view o The user can participate in the communication scenario design o Tasks, documents, information pass from one participant (app or human) to another, according to a set of procedural rules 24

Enterprise Application Integration through Workflow: example 25 Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007

Enterprise Application Integration through Workflow: Workflow Management System (apps) 26 Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007

Workflow Management Systems orchestrate apps and humans in the context of a process Work within the firm combines multiple units of work of small granularity into work units of larger granularity Work within the firm combines multiple units of work of small granularity into work units of larger granularity From this perspective, the operations of a firm look like a process which From this perspective, the operations of a firm look like a process which  includes a set of activities (i.e. tasks)  performed in coordination in an organizational and technical environment…  to realize a concrete business goal 27

Firms as a “budge” of business functions: M. Porter’s Value Chain 28

Firms as a “budge” of business functions: Value System 29

Business Process Management and Information Systems 30 Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007

A business process example 31 Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007

Enterprise Application Integration through Workflow: Workflow Management System (apps + humans) 32 Source: M. Weske, Business Process Management: Concepts, Languages, Architectures, Springer, 2007