Thursday, July 12, 2007

INFORMATION ENGINEERING

What is Information Engineering?
Information Engineering Methodology is a rigorous architectural approach to planning, analysing, designing, and implementing applications within an enterprise. It enables an enterprise to maximize its resources, including capital, people and information systems, to support the achievement of its business vision. It is defined as: "An integrated and evolutionary set of tasks and techniques that enhance business communication throughout an enterprise enabling it to develop people, procedures and systems to achieve its vision". Information Engineering has many purposes, including organisation planning, business re-engineering, application development, information systems planning and systems re-engineering.

The Variants of Information Engineering
There are two variants of Information Engineering (IE). These are called the DP-driven variant and the business-driven variant.
DP-Driven Variant of IE The DP-driven variant of Information Engineering was designed to enable IS Departments to develop information systems that satisfied the information needs of the 1980s - which was largely a DP-driven development environment. Most of the Computer-Aided Software Engineering (CASE) tools available today support this DP-driven variant of IE.
Business-Driven Variant of IE From 1983 - 1986 Clive Finkelstein extended IE strongly into strategic business planning and developed the business-driven variant of Information Engineering. This variant is designed for rapid change in the client/server, object-oriented environment of the business-driven 1990s. Business-driven IE is documented in the later books by Clive Finkelstein.

Stages in the Information Engineering
Information Strategy Planning The fundamental objective of Information Strategy Planning (ISP) is to develop a plan for implementing business systems to support business needs.
Outline Business Area Analysis The OBAA answers a range of questions related to implementation of a business area. Select tasks to include in a particular project that provide support for business decisions and objectives. Specific information needs and priorities for the business area are needed.
Detailed Business Area Analysis The purpose of a DBAA project is to provide detailed models as a solid basis for system design. The methodology helps find the right answers to the right questions. Applying the methodology is never an end in itself.
Business System Design The purpose of a Business System Design project is to specify all aspects of a system that are relevant to its users, in preparation for the technical design, construction, and installation of one or more closely related databases and systems. The key tasks are therefore structured to produce unambiguous consistent specifications, with the volume of detail necessary to make planning and technical design decisions.
Technical Design A Technical Design project prepares an implementation area for construction and installation. The key tasks are structured to produce a system and database that meet the user's acceptance criteria and are technically sound.
Construction The objective of the Construction stage is to produce a system, as defined in the technical specification, on time and within budget. The system should be of an acceptable quality, and contain all necessary operating and user procedures. The task is complete when the acceptance criteria for the business system are met.
Transition Transition is defined as the period during which newly developed procedures gradually replace or are interfaced with existing procedures. The execution of a Transition project obviously demands a thorough understanding of both the system to be installed and the systems to be replaced.

Techniques
Some technigues that are used during an IE project are:
Entity analysis identifies all the things that the enterprise may want to hold data about. The analysis classifies all of the things into different entity types, revealing how they relate to each other. Which is being described in the entity model.
Function analysis and process dependency takes a function (a major business activity) of the enterprise and breaks it down into elementary business processes. From this, two diagrams are prepared: the process decomposition diagram, which shows the breakdown of a business function, and the process dependency diagram, which shows the interdependencies of business processes.
Process logic analysis describes the sequences of actions carried out by a business process and shows which data are used by each action.
Entity type lifecycle analysis describes the significant business changes to entities and confirm that processes have been modelled to effect these changes
Matrix cross-checking creates cross-references between data objects and processes to verify that they are necessary and complete.
Normalization provides a formal means of confirming the correctness of the entity model.
Cluster analysis helps define the scope of design areas for proposed business systems.
Data flow and data analysis makes a comparison possible between the business area models and the systems currently supporting this area, these current systems are analyzed using data flow and data analysis techniques.

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