Chapter 3: AIS Enhancements Through Information Technology and Networks

Transcription

1 Accounting Information Systems: Essential Concepts and Applications Fourth Edition by Wilkinson, Cerullo, Raval, and Wong-On-Wing Chapter 3: AIS Enhancements Through Information Technology and Networks Slides Authored by Somnath Bhattacharya, Ph.D. Florida Atlantic University

2 Importance of IT and Computer Networks to Accountants To use, evaluate, and develop a modern AIS, accountants must be familiar with IT Computers enable accountants to perform their duties more quickly, accurately, and consistently than by manual methods Software such as electronic spreadsheets aid accountants in analyzing financial statements and in developing budgets

3 IT Components of Interest to Accountants Devices for data entry Data Processing Data Communication Information Generation Data Bases Data Modeling concepts Evaluation of internal controls in AIS Variety of software packages Computer Networks

4 Networks & Accountants Because they transmit data and information, networks are an integral part of AIS Networks are vulnerable to high level risk thus requiring special controls and security measures. Need to prevent loss of accounting records & information Need to ensure accuracy of data Networks may be used to consolidate data into financial information

5 Gains from IT for Accountants Faster processing of transactions and other data Greater accuracy in computations of and comparisons with data Lower cost of processing each transaction More timely preparation of reports and other outputs More concise storage of data, with greater accessibility when needed Wider range of choices for entering data and providing outputs Higher productivity for employees and managers, who learn to use computers effectively in their routine and decision-making responsibilities

6 Task Matching to Computers Manual Exceptional/infrequent transactions Setting objectives and policymaking judgments New problems Supervising employees Social communications Making complex strategic decisions Computerized Collecting and processing large volumes of routine transactions Storing large quantities of data and information Monitoring and controlling continuous processes Answering specific inquiries based on stored data Preparing complex analyses and extensive reports Helping gather data and understanding the relationships between all types of decisions Figure 3-1

7 Limitations of Infoage s Legacy AIS Large portion of personnel time and effort spent on systems maintenance Little time & effort for value-added services Little flexibility to changing business conditions Financial and Operational data not integrated Difficult to generate data with both financial and non-financial components The transaction processing systems focus on chart of accounts classification Ignore the multidimensional aspects of transactions Files related to applications are not integrated Inefficiencies of the manual system remodeled in automated form Business processes and accounting procedures not analyzed and improved upon prior to conversion to automated form System not geared to generate timely decisionsupport information Computer programmers required to write new programs for ad hoc queries

8 Types of Network Architectures Wide-Area Networks Formed among computers and interconnected devices that are geographically distant from one another Local-Area Networks A type of distributed network created when two or more linked computers are grouped within a limited geographical area

9 Centralized WANs - I Concentrates all application processing at one geographical location Consists essentially of one (or a cluster of) central mainframe computer(s) and one or more physically remote terminals Typically all hardware, software, and data processing personnel are located at corporate headquarters Advantages include: the concentrated computing power of a large processor low operating costs per transaction leading to economies of scale can facilitate the use of a database approach facilitate better security provisions allow for greater standardization and professional planning and control of information-related activities

10 Centralized WANs - II Best suited for Firms with centralized organizational structures Firms with homogeneous operations Firms with low processing activity at remote sites Examples include Savings and loan institutions Banks with many ATMs and branches Merchandizing chains Motels Airlines Drawbacks include Inflexibility Expensive and complicated software needed Vulnerable to disasters as a result of complete dependence on central computer Not user-friendly

11 Distributed WANs - I This links fully functional computers in different geographical locations. Each remote site processes its own applications. However, users may not have easy access to centralized data or be able to transmit data and information rapidly. Computers may be interconnected by data communications hardware and software to other remote sites and to a central computer facility to form an enterprise-wide network.

12 Distributed WANs - II Distributed databases are useful when: Large volumes of data need to be processed at remote locations Managers and employees need very fast access to data on a frequent basis Databases may be distributed by replication or partition. Replication: Copies of files from the main data base are stored at remote locations Partition: Segments of files are allocated to various locations within the network This avoids data redundancy, but increases the complexity of transmitting data throughout the network Likely to become the dominant approach as technology improves At present most data bases are a hybrid of the two approaches

13 Benefits of Distributed WANs Can be responsive to diverse needs of users Enable network facilities to be used efficiently since processing jobs can be routed to unused computer systems in the network Are robust against individual computer failures Flexible and adaptable to change Best suited for firms with: Decentralized organizational structures Diverse operations or user groups Clustered functions at various locations Multiple products Manufacturing operations A variety of services

14 Drawbacks of Distributed WANs Difficulty in maintaining adequate control and security Each distributed processing location needs its own set of controls and security measures Given the smallness of each location, organizational independence is not easily achieved Managers may sacrifice control and security for greater productivity Difficulty and cost of coordinating the relatively independent and sometimes incompatible computer systems Added costs for multiple computers, other system components, and communication services

15 LANs A LAN may be connected to other LANs and/or WANs via hardware devices known as gateways or bridges At the heart of a LAN is the workstation Microcomputer-based workstation Traditional workstation Super workstation

16 Peer-to-Peer LANs In smaller LANs, every workstation functions as both a client and a server This allows all users to share data and files on all workstations Called peer-to-peer network since no workstations are dedicated to perform only server functions Compared to a server network, peer-to-peer networks are less costly, easier to install, and compare well against server networks of similar size Number expected to significantly increase in the near future

17 Server Networks May interconnect hundreds of workstations More difficult to manage and interpret than peer-to-peer networks Provide greater security than peer-to-peer networks At least one workstation is dedicated to performing specific server tasks Examples include: Servers Database servers Print servers Communications servers Transaction processing servers Large server networks often contain multiple servers

18 The Network Operating System In peer-to-peer networks, the Network Operating Software (NOS) is installed in each user workstation In a server network, most of the NOS is installed in the file server and a portion also resides in each workstation To run centralized LAN applications, the NOS installed in the file server interacts with the NOS and the local operating system installed in the workstation. The client workstation NOS initiates a request to the file server NOS to load files and programs into the client workstation s RAM In a peer-to-peer network, a client NOS initiates a request to another client NOS, which also functions as a server, to load the requested files and/or programs into RAM

19 More Networks Examples of pre-developed network configurations resident in Network Interface Cards include: Ethernet, Token Ring, and ARCnet The International Standards Organization has issued the Open Systems Interconnection (OSI) model Open Systems Architecture Seamless exchange of data, files, and software between LANs and WANs built with multiple vendors hardware, software, and networking components

20 Client/Server Networks This model splits data processing between a user workstation (client) and one or more servers Majority of servers are dedicated database servers, thereby enabling client to share data and files, conduct database searches, and update the database One of the fastest growing segments of IT

21 Cooperative Client/ Server Computing Most commonly implemented mode of client/server architecture Facilitates the optimal sharing of computer resources since the client(s) and server(s) jointly process the data Clients typically employ Graphical User Interfaces (GUIs) Data-processing locale is transparent to the user

22 Network Topologies The STAR and RING topologies apply to both distributed WANs and LANs The BUS topology applies only to LANs All three found in client/server networks All three may be combined to form hybrid configurations

23 The STAR Configuration Figure 3-3a

24 The RING Configuration Figure 3-3b

25 The BUS Configuration Figure 3-3c

26 Enterprise-wide Processing and Data Systems Enterprise-wide on-line transaction processing systems collect and process mission-critical accounting and operational applications Enterprise Resource Planning Systems (ERP) such as SAP R/3 overcome the limitations of legacy applications Firms typically develop two types of On-line Analytical Processing (OLAP) systems that supplement ERP or legacy systems A firm can model the relevant aspects of business events contained within the business processes allowing for the use of relational database-related query language commands Firms can create a data mart or data warehouse to generate predefined reports for executives and other managers

27 Data Marts and Data Warehouses Both Data Marts and Data Warehouses organize and store copies of informational or decision support data A Data Mart stores copies of decision support data in a data base for a portion of a company A Data Warehouse stores copies of decision support data in an integrated data base for an entire enterprise As opposed to applications-oriented data in legacy systems, data in a data mart or warehouse are stored by subject areas (e.g., customers) Data may be stored in both summarized or raw form Both have drill down and data mining features

28 Specialized Inter-organizational Systems/Networks Internet Commerce and Electronic Commerce Point-of-Sale Systems/Networks Electronic Funds Transfer (EFT) Systems Electronic Data Interchange (EDI) Systems Value Added Networks (VANs) The Internet (TCP/IP) The World Wide Web (WWW) Hypertext information retrieval system Intranets Extranets

29 Accounting Information Systems: Essential Concepts and Applications Fourth Edition by Wilkinson, Cerullo, Raval, and Wong-On-Wing Copyright 2000 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in Section 117 of the 1976 United States Copyright Act without the express written permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The publisher assumes no responsibility for errors, omissions, or damages, caused by the use of these programs or from the use of the information contained herein.