Information Systems

what is a system?A system is a collection on interrelated components that work together to perform a specific task or achieve a goal. In a system, the different components are connected with each other and they are interdependent. Each component is a subsystem of the original system and carries out a part of the system task.

Two Types of Systems

Natural SystemsMan Made Systems

Natural Systems River Systems Mountain Systems Air Systems

Natural SystemsEg.The human body represents a complete natural system. Our human body contains complex muscle, bone, respiratory, digestive and circulatory subsystems, each providing a specific part of the system task.

Man Made Systems

Social Systems Formal Organization Transport Systems Communication Systems Automated Systems

subsystemLet us consider the respiratory subsystem which provides air to the body from the environment. Some of the components of the respiratory subsystem includes nasal passages, lungs etc.Each component, such as lungs, can itself be considered as a subsystem. Similarly, the heart and blood vessels can be considered as components of the circulatory subsystem.

Data:Streams of raw facts representing events such as business transactions

Information:Clusters of facts that are meaningful and useful to human beings in the processes such as making decisions

What Is an Information System?

Rely on computer hardware and software

Processing and disseminating information

Computer-Based Information System (CBIS)

Fixed definitions of data, procedures

Collecting, storing, processing, disseminating, using data

Formal Systems

Functions of an Information System

Types of Information Systems

TYPES OF INFORMATION SYSTEMS

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What is MIS ?Keen DefinitionMIS is the development and use of effective information systems in organization.

Broad DefinitionThe design and use of effective information systems in business.

Narrow DefinitionAn information system that facilitates management by producing structured, summarized reports on a regular and recurring basis.

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Problems with MISLack of management involvement with the design of the MIS.Narrow and/or inappropriate emphasis of the computer system.Undue concentration on how low level data processing applications particularly in the accounting area.Lack of management knowledge of computers.Poor appreciation by information by information specialists of management’s true information requirements and of organizational problems.Lack of top management support.

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Key PointsInformation increases knowledge, reduces uncertainty, adds value when used.Data are facts which have been recorded.Information is processed data which is understood by the user.The value of information comes from its use.Good information is :- relevant, accurate, in time to be used, sent to the right person, and is understandable.Communication systems include a source, a message, and the destinationA MIS provides managers at all levels with appropriate information for planning, control and decision making.

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Relationship between Data Processing & MIS

Characteristics of MIS Oriented toward Decision Making Summary Information Medium & Long Range Prediction & Control OrientedCharacteristics of Data Processing Perform the Transaction Processing Detail Data Short Range Real Time Daily Operation Oriented

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The Part of an Information System Personnel

Hardware

ProcessesPrograms

Procedures

Data Files

Inputs Outputs

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The parts of an information system

InputsProcessesData FilesOutputsPersonnelHardware

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SystemsNamed collection of processors tat satisfy some functional need of the business.Combination of manual and computer processors.Will take into account the needs of many functional areas.Considers the day-to-day and management information needs of the organization.

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Goals of Systems includeSupporting the business needs.Supporting management decision makingIntegration with other systems.Reacting to business and technology change.Acceptance and exploitation by employees.Providing a competitive edge.

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Categories of systems

OptionalManagerialStrategic

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Development of systems is far from easy…?

Process of converting more abstract concepts into more absolute products.Many problems to overcome…

Business problems.Technologies, tools and technique problems.Attitudes of the users and exiting development staff.

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Business problems

The lack of a clear direction.A rapid rate of change.No commitments from senior management.Conflicting requirements.Differences in management style.Multiple solutions to the same problem.Differing levels of responsibility.Lack of control.

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Technologies, tools, techniquesThe proliferation of micro-computers.Short life- span of the hardware.A vast range of non-integrated software.Instant worldwide communication raising expectation levels.Tools emerging only recently to help control development.

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Attitudes of users and development staff

Users often do not know what they really want or need.Users find it difficult to communicate their requirements.Systems builders cannot or will not listen to their users and rarely build what is needed.System builders are are often the last people to accept change in their own domain.

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Consequences of problemsSystems

More costly than estimated.Arrived later than expected.Not met the requirements of users.With serious maintenance problems and work load.Application backlog – Software crisis.

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Software Crisis – A problem of Demand and supply of Quality products

Demand1985 = World Wide Software Cost = US $ 140MObserved growth rate = 12% /year

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Software Crisis – A problem of Demand and supply of Quality Products

Supply Status1979 – Only in 7 (seven) US Govt Projects.Paid for but not delivered= US $ 3.2 MillionDelivered but not used = US $ 2.0 MillionAbandoned or reworked = US $ 1.3 MillionUsed after changes = US $ 0.2 MillionUsed as delivered = US $ 0.1 Million

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Improvements proposedStructure programming Techniques.Systems Life Cycle Approach.Structured Systems Development Methodologies.Prototyping and CASE orientation.Reusable Software Libraries.Formal Methods.