What is Information Syste1

What is Information System: The largest growth in most economies is coming from 'information' industries. The success of such knowledg e-bas ed organisations lies in their informat ion systems. Also, force d by technological change and global isation of markets, many manufacturing industries are also placing increasing emphasis upon information systems. Information systems are more than just computer programs. Though informa tion and commu nicati ons technologies are playing an increa sing role in meeting organisations’ information needs, an information system is a much more general concept. It refers to the wider systems of people, data and activities, both computer-based and manual, that effectively gather, process, store and disseminates organisations’ information. A Transaction Processing System or Transaction Processing Monitor is a set of information which process the data transaction in database system that monitors transaction programs (a special kind of program). The essence of a transaction program is that it manages data that must be left in a consistent state. Characteristics of Transaction Processing Systems •1. A TPS records internal and external transactions for a company. It is a repository of data that is frequently accessed by other systems •2. A TPS performs routine, repetitive tasks. It is mostly used by lower-level managers to make operational decisions •3. Transactions can be recorded in batch mode or online. In batch mode, the files are updated periodically; in online mode, each transaction is recorded as it occurs. •4. There are six steps in processing a transaction. They are data entry, data validation, data processing and revalidation, storage, - output generation, and query support. Batch processing is execution of a series of programs ("jobs") on a computer without manual intervention.Batch jobs are set up so they can be run to completion without manual intervention, so all input data is preselected through scripts or command-line parameters. Online transaction processing, or OLTP, refers to a class of systems that facilitate and manage transaction-oriented applications, typically for data entry and retrieval transaction processing. OLTP has also been used to refer to processing in which the system responds immediately to user requests. An automatic teller machine (ATM) for a bank is an example of a commercial transaction processing application. E.G. of TPS: # Manufacturing and Production: system that supply data to operate, monitor& control the production process i.e. purchasing, scheduling,receiving,shaping,etc. # Sales & Marketing: syste m that suppor ts sales and marketin g functi on by facilitating the movement of goods & services from producers to employee. Such support system keeps customer record, follow pu telemarketing, etc. # Finance & marketing system: system that maintain, record concerning the flow of funds in the firm & produce financial statement, such as B/S, Income statement etc. # Humen Resource System: system that deals with requirement, Placement, performance evaluation, compensation, carrier development of firms employees personal records keeping applicant tackling position training & skills , benefit. A Manageme nt information system (MIS) is a system or process that provides information needed to manage organizations effectively. Management information systems are regarded to be a subset of the overall internal controls procedures in a business, which cover the applic ation of people, docume nts, technologie s, and proce dures used by management accountants to solve business problems such as costing a product, service or a business-wide strategy. Management information systems are distinct from regular information systems in that they are used to analyze other information systems applied in operational activities in the organi zation. Academically, the term is commonly used to refer to the group of information management methods tied to the automa tion or suppor t of human decision making, e.g. Decision Support Systems, Expert systems, and Executive information systems. Characteristics Of MIS: 1. Information as a resource: Information is the major ingredient of any MIS. So, an MIS should be treated as a resource and managed properly. 2. Manageme nt directed: When MIS is management-oriented, it should be directed by the management because it is the management who tells their needs and requirements more effectively than anybody else. 3. Integrated: It means a comprehensive or complete view of all the sub systems in the organization of a company. Development of information must be integrated so that all the operational and functional information sub systems should be worked together as a single entity. This integration is necessary because it leads to retrieval of more meaningful and useful information 4. User friendly/Flexibility: An MIS should be flexible i.e. there should be room for further modification because the MIS takes much time in preparation and our environment is dynamic in nature. MIS should be such that it should be used independently by the end user so that they do not depend on the experts 5. Sub System concept: When a problem is seen in 2 sub parts, then the better solution to the problem is possible. Although MIS is viewed as a single entity but for its effective use, it should be broken down in small parts or subsystems so that more attention and insight is paid to each sub system. Role of MIS in an Organization: Management and organizations facing constantly changing problems, diverse managerial styles, and ever present information needs offer a challenging context for developing computer based information systems. MIS uses computer technology to provide information and decision support to managers, helping them becomes more effective. Developments in the young computer industry are changing corporate management style. An organization is traditionally viewed as a three level pyramid-operational activities at the bottom, management planning and control activities in the middle and strategic planning and policy making in top management. The corporate database contains data relating to the organization, its operations, its plan and its environment. # Supports day to day business operation # supports managerial decision making. # supports strategic decision making a competitive decision making. # opting operational cost. # provide timely and accurate information. A Decision Support System (DSS) is a class of information systems (including but not limited to computerized systems) that support business and organizational decision-making activities. A properly designed DSS is an interactive software-based system intended to help decision makers compile useful information from a combination of raw data, documents, personal knowledge, or business models to identify and solve problems and make decisions. Characteristics Of DSS: 1. Helps decision makers to take decision rather that replace them. 2. Have title or Reasoning capability. 3. suppotr alternative enquiry & responses. 3. DSS are use to aid semi structured or unstructured decision. 6. produce information on & hoc flexible & adoptive format. 7. information is produced by analysis of optional and external data. 8. analysis and support comparison of specific alternative decisions. 9. They are flexible, adoptive & quick. An expert system is software that attempts to provide an answer to a problem, or clarify uncertainties where normally one or more human experts would need to be consulted. Expert system is most common in a specific problem domain, and is a traditional applic ation and/or subfie ld of artificial intelligence. Expert systems may or may not have learning compon ents but a common element is that once the system is developed it is proven by being placed in the same real world problem solving situation as the human SME, typically as an aid to human workers or a supplement to some information system. Characteristics of Expert System: 1. Captures knowledg e and expert ise of a problem solve r & decis ion maker. 2. Replace a humen advisor for spec ific domain of knowledge. 3. Its domain of knowledge is more . 4. Has reasoni ng and explan ation capability. 5. types of problem tested are relative. 6. Direction of interaction is from machine to user. Advantages : 1. Provides consistent answers for repetitive decisions, processes and tasks. 2. Holds and maintains significant levels of information. 3. Encourages organizations to clarify the logic of their decision-making. 4. Always asks a question, that a human might forget to ask. 5. Can work continuously (no human needs). 6. Can be used by the user more frequently. 8. A multi-user expert system can serve more users at a time. Components of Expert System: A database consists of an organized collection of data for one or more multiple uses. One way of classifying databases involves the type of conten t, for example: bibliographi c, full-t ext, numeric, image. Other class ifica tion methods start from examining database models or database architectures. A database management system (DBMS) consists of software that organizes the storage of data. A DBMS controls the creation, maintenance, and use of the database storage structures of social organizations and of their users. Advantages of database: 1.Reduce redundancy. 2. Improve consistency. 3. Data independence. 4. Data sharing by multiple Application. 5. centralized control. 6. Data security. 7. integrity of databse. 8.balancing conflicting requirements. Database Users: 1. Nat ive User - invoke one of the permanent applic ation program that have seen writte n previo usly. 2.Application Programmer: Interect with system through DML calls. 3. Sophistecated Users: form request in a database quary language. 4. Specialist Users: write specialized database application that doesnot fit into the traditional data processing. Data administrat ion or data resource management is an organizational function working in the areas of information systems and computer science that plans, organizes, describes and controls data resources. A data administrator is responsible for:A. maintaining database system software. B. defining data elements, data names and their relationship. C. developing physical database structures. D. developing data dictionary system software. E. Schema definition. F. Acting as a liaison with user. Advantages of DBMS: 1. Warehouse of Information: The database management systems are warehouses of information, where large amount of data can be stored. The common examples in commercial applications are inventory data, personnel data, etc. 2. Systematic Storage: The data is stored in the form of tables. The tables consist of rows and columns. The primary and secondary key help to eliminate data redundancy, enabling systematic storage of data. 3. No Language Dependence: The database management systems are not language dependent. Therefore, they can be used with various languages and on various platforms. 4. Data Security: Data is the most important asset. Therefore, there is a need for data security. Database management systems help to keep the data secured. 5. Data Consistency; Data consistency ensures a consistent view of data to every user. It includes the accuracy, validity and integrity of related data. The data in the database must satisfy certain consistency constraints. The primary key of a relational table uniquely identifies each record in the table. It can either be a normal attribute that is guaranteed to be unique (such as Social Security Number in a table with no more than one record per person) or it can be generated by the DBMS (such as a globally unique identifier, or GUID, in Microsoft SQL Server). Primary keys may consist of a single attribute or multiple attributes in combination. a foreign key is a referential constraint betwe en two tables. [1] The foreign key identifies a column or a set of columns in one (referencing) table that refers to set of columns in another (referenced) table. The columns in the referencing table must be the primary key or other candidate key in the referenced table. a candidate key of a relation is a minimal superkey for that relation; that is, a set of attributes such that 1. the relation does not have two distinct tuples with the same values for these attributes (which means that the set of attributes is a superkey). 2. there is no proper subset of these attributes for which (1) holds (which means that the set is minimal). A super key is defined in the relational model of database organization as a set of attributes of a relation variable (relvar) for which it holds that in all relations assigned to that variable there are no two distinct tuples (rows) that have the same values for the attributes in this set. Equivalently a super key can also be defined as a set of attributes of a relvar upon which all attributes of the relvar are functionally dependent. RDBMS is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. Most popular commercial and open source databases currently in use are based on the relational model. A short definition of an RDBMS may be a DBMS in which data is stored in the form of tables and the relationship among the data is also stored in the form of tables. A functional dependency occurs when one attribute in a relation uniquely determines another attribute. This can be written A -> B which would be the same as stating "B is functionally dependent upon A." Partial dependency; In database terminology, a partial functional dependency occurs when the value in a non-key attribute of a table is dependent on the value of some part of the table's primary key (but not all of it). Normalization: In the field of relational database design, normalization is a systematic way of ensuring that a database structure is suitable for general-purpose querying and free of certain undesirable characteristics—insertion, update, and deletion anomalies—that could lead to a loss of data integrity. Transaction management: A database transaction comprises a unit of work performed within a database management system (or similar system) against a database, and treated in a coherent and reliable way independent of other transactions. Transactions in a database environment have two main purposes: 1. To provide reliable units of work that allow correct recovery from failures and keep a database consistent even in cases of system failure, when execution stops (completely or partially) and many operations upon a database remain uncompleted, with unclear status. 2. To provide isolation between programs accessing a database concurrently. Without isolation the programs' outcomes are possibly erroneous. Decomposition: To achieve normalization sometimes we have to decompose the table. i.e. to split the table into two or more table. 1. Loss less decomposi tion- no information will be lost after decomposition. 2. lossy decomposition- some information could be lost when we decompose the tables. Concurrency control ensures that correct results for concurrent operations are generated, while getting those results as quickly as possible. Computer systems consist of modules. Each module is designed to meet certain consistency rules. When modules that operate concurrently interact by messaging or by sharing data, a certain module's consistency may be violated by another module. Concurrency control provides rules, methods, and design methodologies to maintain the consi stency of module s operat ing concurrentl y while interact ing, and thus the consis tency of the whole syste m. Operation consistency and correctness should be achieved together with operation efficiency. Why concurrency control is needed? 1. Lost update problem: One transaction writes a value of a data-item (datum) on top a value written by a second concurrent transaction, and the first value is lost to other transactions running concurrently and need, by their precedence, to read the first value. 2. The temporary (or dirty) read problem: Transactions read a value written by a transaction that has been later aborted. This value disappears from the database upon abort, and should not have been read by any transaction ("dirty read").3. The incorrect summary problem: While one transaction takes a summery over values of a repeated data-item, a second transaction updated some instances of that data-item. The resulting summary does not reflect a correct result for any precedence order between the two transactions (if one is executed before the other), but rather some random result, depending on the timing of the updates, and whether a certain update result has been included in the summary or not. Risk management: Risk is defined in ISO 31000 as the effect of uncertainty on objectives (whether positive or negative). Risk management can therefore be considered the identification, assessment, and prioritization of risks followed by coordinated and economical application of resources to minimize, monitor, and control the probability and/or impact of unfortunate events [1] or to maximize the realization of opportunities. Risks can come from uncertainty in financial markets, project failures, legal liabilities, credit risk, accidents, natural causes and disasters as well as deliberate attacks from an adversary. Risk assessment is a step in a risk management process. Risk assessment is the determination of quantitative or qualitative value of risk related to a concrete situation and a recognized threat (also called hazard). Quantitative risk assessment requires calculations of two components of risk: R, the magnitude of the potential loss L, and the probability p, that the loss will occur. A project risk can be divided into 3 category: 1. cost Risk in the degree of uncertainty associated with budget. 2. Performance risk: is the possibility that the system will be unable to deliver al or some of the benefits or will not perform according to the requirement. 3. Schedule risk Is the degree of uncertainty associated with the project schedule. Risk Control: risk control is essential to the prudent operation of any institution or project and to promoting stability of the financial system as a whole. Risk control has a wider ambit than risk management. Risk control is the entire process of policies, procedures and systems an institution needs to manage prudently all the risks resulting from its financial transactions, and to ensure that they are within the bank's risk appetite. A work breakdown structure (WBS) in project management and systems engineering, is a tool used to define and group a project's discrete work elements (or tasks) in a way that helps organize and define the total work scope of the projec t [1] . A work breakdown structure element may be a product, data, a service, or any combination. A WBS also provides the necessary framework for detailed cost estimating and control along with providing guidance for schedule development and control. Additionally the WBS is a dynamic tool and can be revised and updated as needed by the project manager SAQ (System qual ity assuranc e) : refers to a program for the systematic monitoring and evaluation of the various aspects of a project, service, or facility to ensure that standards of quality are being met. There are three levels of quality assurance: Testing- in system testing the view is to estimate program errors. Validation- system validation cheeks the system in both stimulated and live environment. Verification- it is a process of checking whether we are developing the system correctly. Certification: once the system has passed the above three steps, a certificate is issued to certify that system is correct and conform the standards. Data Warehouse: ! A subject-oriented, integrated, time-variant, non-updatable, collection of data used in support of management decision-making processes ! Subject-oriented: e.g. customers, patients, students, products, ! Integrated: Consistent naming conventions, formats, encoding structures; from multiple data sources. ! Time-variant: Can study trends and changes ! Non- updatable: Read-only, periodically refreshed. ! Integration data warehouse must put data from disparate sources in to a consistant format. ! Work Load: Data warehouse are designed to accommodate ad hoc quarries . Users may not know the workload of your warehouse in advance. ! data modification: a data warehouse is updated on regular basis using bulk data modification technique.

What is Information Syste1

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