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Information System Architecture. The data is the raw material of any I.S. Before becoming information, the data must be created, stored, processed, analyzed and distributed .
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The data is the raw material of any I.S. Before becoming information, the data must be created, stored, processed, analyzed and distributed. Information systems can be characterized by their functions: the generation, storage, presentation, exchange, interpretation, transformation, and transportation of information. Information system
An application-centric view of IS • Applications, developed independently of each other, provided functionality that can only be used within the boundaries of each application. • Differences between platforms, programming languages, and protocols created technology boundaries that are not easy to cross. • As a result enterprises lost the flexibility the agility they need in the marketplace; IS stopped being part of a solution and became more of a problem; enterprises ISs locked them into specific ways of, and created barriers to, carrying out Business.
Architecture Design 1/3 • “An architecture is the fundamental organization of a system embodied in its components, their relationships to each other, and to the environment, and the principles guiding its design and evolution.”IEEE STD 1471-2000 Is used to: • Make buy decisions. • Discriminate between options. • “Discover” the true requirements. • Drive one or more systems to a common “use” or purpose. • Develop system components. • Build the system. • Understand and conduct changes in the system as the BP is modified.
Architecture Design 2/3 • It focuses on the creation of new systems designed to play a role in some business environments. • A key factor is the systematic, controlled and coordinated development of systems’ components and the ability to keep overview over the complexity of the system. • The way to do this is to use models to describe parts or aspects of a system. A set of models that together define the essentials of a system is called the architecture of the system. • The architecture of a system plays different roles, in the development process and during the life cycle of a system.
Architecture Design 3/3 • Besides the development of totally new systems it becomes more and more important to consider the renewal or renovation of existing systems. This requires different approaches and introduces new challenges. • One of the major issues is that the systems engineers have to understand the system that has to be renovated. An existing system puts extra constraints on the development of new parts which makes renovation different from development from scratch.
Architecture Framework • “An architecture framework is a tool… It should describe a method for designing an information system in terms of a set of building blocks, and for showing how the building blocks fit together. • It should contain a set of tools and provide a common vocabulary. It should also include a list of recommended standards and compliant products that can be used to implement the building blocks.” [TOGAF 8, OpenGroup]
Resources management, enterprise organization, production management. Enterprise engineering
Business Management Economiy, cognitive, trust management… etc.
Computer science • Information system, decision making systems…etc.
Organizations Locations Functions Applications Entities Database/file Tech Platform Operational Node Name Needline Name Operational Activity Link Name/ID Systems Node Name System Name System Component Name Organizations Locations Functions Applications Entities Database/file Technology Platforms X X X X X System Function Name Component Interface Name X X X X X X Architecture Products:Graphic, Textual, and Tabular… Graphic Text Tabular Dictionary Relationships Use products to: Analyze Capture Communicate
Enterprise competitive edge • An enterprise’s competitive edge and ultimate success are enabled by its ability to rapidly respond to changing business strategies, governance, and technologies. • The competitive edge translates into higher levels of customer satisfaction, shorter work cycles, and reductions in schedules, maintenance costs, and development time, all resulting in lower overall cost of ownership.
Enterprise Architecture • Enterprise Architecture is the key facilitating ingredient providing a holistic view and a mechanism for enabling the design and development as well as the communication and understanding of the enterprise. • The goals of enterprise architecture are to manage the complexity of the enterprise, align business strategies and implementations, and facilitate rapid change in order to maintain business and technical advantages. • IS Enterprise Architecture is like urban planning.
Consists of cutting out IS in autonomous modules, of more and more small size, in a way similar to the city. Between these modules we establish zones of information exchange, which render possible to decouple the various modules. Urban planning …..What!!?
Urbanisation: the goal? • They can be evolved/removed separately while preserving their ability to: • Interact with the remainder of the system. • Replace some of these subsystems (inter-changeability). • Guarantee the possibility to integrate subsystems of various origins (integration). • Strengthen the capability to interact with others ISs (Interoperability).
Important rules of Urbanisation • The autonomy of functional system’s components. • The crosscutting nature of the functionalities applied on all system components should be thought to provide an end to end homogenous solutions. • Avoiding the “spaghetti” effect in the enterprise’s information system. • These principles enable the agility of the information system to align with the changes in the enterprise organisation and strategy entrained by markets’ changes.
Urbanization, the what and why? City planning metaphor: How to re-organize or evolve a city while keeping a normal life for city’s inhabitants during the construction or re-construction? In the same way: how to re-organize the IS without totally destroying the existing applications and while maintaining IS functionalities during the re-construction; IS must be reorganized to facilitate its evolution while protecting its informational legacy.
Urbanisation : what else? Allows establishing the link between: mission of the organization, exchanges, internal and external actors, business event, business process, information, applications and infrastructure. Provide a complete description of IS on functional, organisational and technical levels. Being a decision-making support tool to understand change impacts during the evolutions (business, functional, applicative, and technical).
Multilayer approach! The methodology is based on a reference framework integrating four views from the information system: Business view: it describes all the business activities of the enterprise that the information system must support. Functional view: it describes the information system functions which support the business process. Applicative view: it describes all the applicative elements of a data processing system. Technical view: it describes all the hardware, software and technologies used to support the functionality of the information system.
Ishikawa diagram The strategy is modelled by a hierarchy of goals represented by ISHIKAWA diagrams, breaking up them into sub-objectives until reaching the lower level in which all the objectives are achieved by at least one process. This diagram is constrained by the following rules (urbanisation rules for the diagram of objectives): The same objective appears once and only once in the diagram. If an objective is divided in sub-objectives the list of those must be exhaustive. An objective of the lower level must be associated to one or more of performance indicators.
Urbanisation and BP Tiré des cours: C. Costaz
Urbanisation Modeling Tiré des cours: C.Costaz
Processes Identification Operational processes Monitoring and Governance Support
Urbanisation Business Functions Tiré des cours: C.COSTAZ
Urbanization rules IS urbanization initiative should satisfy the following rules: Affiliation: in the hierarchical decomposing of an information system, each component belongs to one and only one unit. Autonomy: no dependency should exist between units; a unit can deal with an Event from start to end, without the need for treatment in another unit. Asynchronism: a unit can handle an event and send the result without waiting for the response from the receiver. Data Normalization: the results produced by each unit are based on recognized standards. Single Exit Point: the information in each unit is sent by a single point. Data Ownership: each unit is responsible for its own data; updates of these data are carried out by each individual unit. Passage Point: units communicate indirectly via an Entity which is responsible for data flow management.
Service Oriented Architecture • Today, component based development is considered to be the most promising way of developing information systems. • The idea is instead of constructing the software from scratch; we achieve a selection, re-configuration and assembly of existing components. Of course there is always a need for new components. • The idea is to reuse existing components to compose different functions using particular mechanisms in order to satisfy specific needs of a given business domain or environment.
What is SOA? • Applications must open up their capabilities for use by other existing/new applications. • It must be possible to combine the services offered by different applications to create higher-level services or composite applications. • Technology differences must not matter; interoperability must be a key goal. • Open standards must be adopted to enable integration across enterprises. • Attention must be paid to governance and manageability in order to make sure that flexibility granted by the first three principles does not lead to chaos.
What is SOA? • Services: distinct units of loosely coupled technical or business functions, which can be distributed over a network and can be invoked, combined and reused to create new business processes. • These services communicate with each other by passing messages from one service to another, and by coordinating their activities using an orchestrator. • Orchestrator: a part of the middleware assembling published services and coordinating their interactions into business flows.
SOA principals? The use of explicit implementation-independent interfaces to define services (adaptors). The use of communication protocols that stress location transparency and interoperability. The definition of services that encapsulate reusable business function.
Middleware capabilities Security. Transformation (Data). Mediation (functional and semantic). Routing. Monitoring. Tracing. End to end QoS. Searching and matching. Invocation.
What qualifies as a service? • A service is defined at the right level of granularity, from the point of view of a service consumer. • A service is discoverable. Consumers looking for a service can discover its presence, usually by looking up a service registry (as la the yellow pages in a phone directory). • A service is self-describing. Potential consumers can learn by themselves how to invoke the service. • A service is technology-agnostic. Potential consumers are not constrained from using the service because of a mismatch in hardware or software platforms. • A service can be composed with other services to create a higher-level service.
SOA « typical » standards • UDDI: Universal Description, Discovery and Integration. • WSDL: Web Services Description Language. • SOAP: Simple Object Access Protocol.
Services Client 2 - HTTP Get Seache a service Services directory (UDDI) 3 – WSDL (encapsulaed in a SOAP) 1 service Publication 4 - request “Soap” service Invocation Service Provider 5 - response “Soap”
Composite service ? I want to pass tow weeks in a cold, dry, not very far, and cheap country with a lot of touristy views Services geographic Info. touristy Info. Weather Info. Plane tickets Travel Agency Hotels Car rental
What is UDDI • Stands for Universal Description, Discovery and Integration. • UDDI is a directory for storing information about web services. • UDDI is a directory of web service interfaces described by WSDL. • UDDI communicates via SOAP.
How can UDDI be Used? • If the industry published an UDDI standard for flight rate checking and reservation, airlines could register their services into an UDDI directory. • Travel agencies could then search the UDDI directory to find the airline's reservation interface. • When the interface is found, the travel agency can communicate with the service immediately because it uses a well-defined reservation interface.
