Management Information Systems Charles Parker 2nd Edition Chapter 7: Data Management Prepared By: Hamad Raza (Lecturer GCUF)

Basic Concepts Data the starting point in Information Systems Today’s business enterprises cannot survive or succeed without quality data about their internal operations and external environment. Data Management Database management involves monitoring, administration & maintenance of the databases & database groups in an enterprise. Data is basically stored in the form of files or databases in an enterprise. The Data Management Hierarchy to store data is as follows: Bit-Byte-Field-Record-File-Database

ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT File Organization Terms and Concepts Bit: Smallest unit of data; binary digit (0,1) Byte: A Collection /Group of bits that represents a single character. Field: A Collection /Group of bytes /words or a complete number representing a single attribute.

ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT File Organization Terms and Concepts Record: A Collection /Group of related fields associated with a single person, object, entity & so on. File: A Collection /Group of related records about a particular set of people, object, entities & so on. Database: A Collection /Group of related files

Figure 7-1 ASCII = American Standard Code for Information Interchange is a character-encoding scheme originally based on the English alphabet.

Major Issues in Data Management All issues regarding the effective management of data fall into at least one of the following categories: Content: What data should the organization collect in the future? What data is it currently collecting? Access: In what ways must an authorized users access data in order to effectively perform their jobs? This involves timing required to get data to users when they need it and which user have a right to which data. Organization: In what ways should data be logically and physically organized to achieve the types of data accesses required by users? Accuracy: Which validation, editing & auditing procedures are necessary in every stage of the input-processing-output cycle to ensure that data and information generated from the data are correct?

Major Issues in Data Management Integrity: What controls are necessary in each stage of the input- processing-output cycle to ensure that data are up to date & that changes to specific occurrences of data are made everywhere in the system? Security: How will data be protected from such possible events as unauthorized access, unauthorized modification, outright theft & unintentional damage. Privacy: How will data be safeguarded to protect the rights of an individuals to privacy? Cost: How should data related costs be controlled? Design (in the light of above issues) User Interface: User are most likely to directly interface with computer based file & databases at terminals or microcomputers by using database management software. There are two types of data base management software or user interfaces: File Management Database Management Systems (DBMS)

File Based Systems Data properly identified and understood when stored in a file (e.g. Customer File, Invoice) In File processing, data is physically arranged/organized in files. Display Terminals (is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer) Started the concept of handling data in files Issues in File Based System Multiple file usage (integrating data from 2 or more files) Data Redundancy Data Updation Slow Processing Advantages of File Based System In-expensive Simple to use

Problems of File Processing Data Redundancy – duplicate data requires an update to be made to all files storing that data Lack of Data Integration – data stored in separate files require special programs for output making ad hoc reporting difficult Data Dependence – programs must include information about how the data is stored so a change in storage format requires a change in programs

Data Access & Organization Methods Organizing & accessing data are two of the driving forces behind data management. Organizing data involves arranging data in storage so that they may be easily accessed. Accessing data refers to retrieving data from storage.