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Enterprise Resource Planning




                    notes          introduction

                                   Development of information system solutions to business problems is a responsibility of any
                                   business professional today. As a business end user he will have to initiate and provide inputs
                                   for development of effective information systems for his company. The business end user has the
                                   responsibility of using the system and continuously initiating improvements. As an IT Manager
                                   his  responsibility  will  consist  of  managing  the  development  efforts  of  Information  System
                                   specialists.
                                   The systems approach to problem solving uses a system orientation to the process of developing
                                   an  information  system.  The  activities  are  inter-related  and  require  the  involvement  of  every
                                   business end user in addition to the IS professionals.
                                   The system approach involves:
                                   1.   Recognising and defining the problem or opportunity

                                   2.   Evaluating alternative system solutions
                                   3.   Selecting the ‘Best fit’ solution
                                   4.   Designing the selected solution
                                   5.   Implementing and evaluating the success of the designed system.
                                   When a systems approach to problem solving is applied to the development of information system
                                   solutions  to  business  problems,  it  is  called  information  systems  development  or  application
                                   development. However before we look at the application development we need to understand
                                   the information system architecture.

                                   12.1 information system architecture

                                   The information system architecture, according to Synnott (1987), is a conceptual framework
                                   for  the  organizational  IT  infrastructure.  It  is  a  plan  for  the  structure  and  integration  of  the
                                   information  resources  in  the  organization.  Synnott  proposes  a  model  for  information  system
                                   architecture,  which  comprises  of  two  major  parts.  The  centralised  portion  serves  the  entire
                                   organization and it includes the business architecture (information needs of the organization),
                                   the data architecture, and the communications architecture. The decentralized (upper) portion
                                   focuses  on  an  organizational  function  or  on  some  service  or  activity  (e.g.  human  resources,
                                   computers, end-user computing, and systems). Each entity includes operational, managerial and
                                   strategic applications.
                                   Types of Information system Architecture: One way to classify information system architecture
                                   is by the role the hardware plays. It is possible to distinguish two extreme cases: a mainframe
                                   environment  and  a  PC  environment.  The  combination  of  these  two  creates  a  third  type  of
                                   architecture, the distributed or networked environment.

                                   Mainframe environment - in the mainframe environment, a mainframe computer does processing.
                                   The users work with passive (or “dumb”) terminals, which are used to enter or change data and
                                   access information from the mainframe. This was the dominant architecture until the mid 1980s.
                                   Very few organizations use this type of architecture exclusively today. An extension of it is an
                                   architecture where PCs are used as smart terminals. Yet, the core of the system is the mainframe
                                   with its powerful storage and computational capabilities. The network computers (NCs) that
                                   were introduced in 1997 are redefining the role of the centralized computing environment.
                                   PC Environment - In the PC configuration, only PCs form the hardware information architecture.
                                   They  can  be  independent  of  each  other,  but  normally  the  PCs  are  connected  via  electronic
                                   networks. This architecture is common for many small and medium-size organizations.





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