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					INFORMATION SYSTEM
Basic System Concepts
System: a collection of elements that interact to achieve a goal
particular.
According to Jerry FithGerald; system is a network of procedures
interconnected, gathered together to perform an activity or
completing a certain goal.
System Characteristics:
• Have a component;
A system consists of a number of interacting components, working together
form a unity. The components of the system can be a subsystem
or parts of the system. Each system no matter how small, always
contains the components or subsystems. Each subsystem
has the properties of the system to perform a particular function and
affect the overall system. A system can have a
larger system called the supra-system, for example, a company can
referred to as a system and industry that is larger systems can
called the supra-system. If the industry is seen as a system, then
companies can be called a subsystem. Likewise, if the employer is deemed
as a system, then the accounting system is subsistence.
• Limit system (boundary);
Boundary is an area that limits the system between a system with a system that
other or with the outside environment. Limit of this system allows a system
viewed as a whole. Limit of a system showing the scope (scope)
of the system.
• The environment outside the system (environment);
Is anything outside the boundaries of the system that affect the operation of the system.
• Liaison system (interface);
Is a media liaison between one subsystem to another subsystem.
• Enter the system (input);
Energy is put into the system. Input can be input
maintenance (maintenance input) and input signal (input signal). Maintenance input
is the energy that is inserted so that the system can operate. Signal input
is the energy that is processed to obtain the output. For example in the system
computer, the program is the maintanance inputs used to operate
computer and data is input signal to be processed into information.
• Output system (Output);
Is the result of the energy processed by the system.
• Processing systems (Process);
Is the part that processes the input to be output as desired.
• Target system;
If the system does not have a target, then the operating system will not be any good.
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Classification System:
• abstract system; system in the form of thoughts or ideas that are not apparent
physical (system of theology)
Physical systems; an existing physical system (computer systems, accounting systems,
production systems, etc..)
• natural systems; system that occur through natural processes. (Solar system, outside the system
space, etc. reproductive system.
Man-made systems; system designed by humans.
Man-made systems that involve human interaction with machines called humanmachine
system (example; information systems)
• System Specific (deterministic system); operate with behavior that is
predictable. Interaction of its parts can be detected with certainty that
output of the system can be predicted (example: computer systems)
Indeterminate systems (probabilistic system); system that conditions the future can not be
predictable because it contains elements of probability.
• Closed system (closed system); systems that are not related and are not affected
with external systems. This system works automatically without interfering
hands of outside parties. Theoretically such a system exists, but the reality is not
there is a system that is completely closed, there was just Relatively closed system (in
relatively closed, not completely closed).
Open system (open system); system-related and affected by
outside environment.
More specifically known also called the automated system; that is part
of man-made systems and berineraksi with control by one or more computers
as part of the system used in modern society.
Automated systems have several components, namely;
�� Hardware (CPU, disks, printers, tape).
�� software (operating systems, database systems, communication control program,
application program).
�� Personnel (who operate the system, providing input, output consumed
and perform activities that support manual systems).
  The
�� data (which must be stored in the system for a certain period).
�� Procedures (instructions and policies for operating systems).
Automated system is divided into a number of categories:
♦ On-line systems. On-line system is a system that receives direct input on the area
where the input was recorded and produced output that could be a result
computing in the areas where they are needed. Area itself can be broken down in
scale, for example, hundreds of kilometers. Normally used for air freight reservations,
railway reservations, banking, etc..
♦ Real-time systems. Real-time system is a mechanism of control, data recording,
processing is very fast so that the resulting output can be received in time
relatively equal. The difference with on-line system is the unit of time used
real-time typically a hundredth or a thousandth of a second on-line while still dalah
scale of seconds or sometimes even a few minutes. Other differences, on-line usually
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only interact with the wearer, while real-time interacting directly with
wearer and the environment are mapped.
♦ Decision support system + system strategic planning. Systems that process transactions
organizations on a daily basis and help managers make decisions, evaluate
and analyze the organization's goals. Used for payroll system, the system
reservations, accounting systems and production systems. Usually shaped statistical package,
marketing package, etc.. This system not only records and displays the data but also
mathematical functions, statistical data analysis and display of information in the form
graphics (tables, charts) as a conventional report.
♦ Knowledge-based system. Computer programs are made close to the capabilities and
knowledge of an expert. Commonly used hardware and
specialized software such as LISP and PROLOG.
Systems based on the basic principles are generally divided into:
• The system is specialized; is a difficult system in an environment diterakpan
different (eg systems biology; fish are transferred to landline)
• large system; is a system that serves most of its resources to
Daily care (eg dinosaurs as a biological system spends most
of his life as eating and eating).
• System as part of another system; system is always a part of the system
larger, and can be divided into smaller systems.
• developing systems; although not applicable to all systems but almost all
system is always evolving.
Perpetrators system consists of 7 groups:
1. User;
In general there are three types of users, namely the operational, supervisory and executive.
2. Management;
Generally consists of three types of management, namely management of users in charge
address use where a new system implemented, the management system involved
in the development of the system itself and the general management involved in
strategic planning systems and decision support systems. Group
management is usually involved with decisions relating to people, time
and money, for example;
"The system must be capable of performing the function of x, y, z, otherwise it should be developed
within six months with the involvement of programmers from the department of w, with
cost of x ".
3. Examiner;
The size and complexity of systems that work and the natural form of organization where the system
The conclusions need to be implemented to determine whether or not the examiner.
Examiner usually determines everything under standard measures
developed in many of its peers.
4. Analyzer systems;
Among other functions as:
- Archaeologists; namely that track how long the system is actually running,
how the system is run and all matters relating to the old system.
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- Innovators: namely that helps users develop and open up horizons
for other possibilities.
- Mediator; that is running the communications functions of all levels, among other
users, managers, programmers, inspectors and other system actors
may not have the attitude and the same light.
- The head of the project; analyzer system should be more experienced personnel
from the programmer or designer. Besides considering the analyzer system generally
determined in advance in a job before the other work, is
it's okay if the person in charge of work into the system analyzer portion.
5. Designing the system;
Designing the system receives the results of analyzer systems in the form that the user needs
not oriented to a particular technology, which is then transformed to design
high level architecture and can be formulated by the programmer.
6. Programmer;
Working in the form of program design results that have been received from the designer.
7. Operating personnel;
Duty and responsibility at the center of the computer such as network, security
hardware, software security, printing and backups. Actors may
not required when the system is running is not large and does not require classification
specifically to run the system.
The basic point in system development
Analyzer system is part of a team that works to develop a system that
has high efficiency and meet the needs of end users. This development
influenced by a number of things, namely:
• Productivity, the current system needs more, better and faster.
It needs more programmers and systems analysts are qualified,
extra working conditions, the ability of users to float its own, language
better programming, better system maintenance (generally 50% to
70% of resources are used for system maintenance), use of technical disciplines
software and automated systems development.
• reliability, time spent on testing the system in general spend
50% of the total system development time.
Within 30 years a number of systems used in various companies
encountered an error and ironically is not very easy to change it. If there
errors, there are two ways you can do, which is tracking the source
errors and must find a way to correct such errors by
replace the program, eliminating a number of old statement or add
number of new statements.
• Maintabilitas, treatment includes;
- Modification of the system according to the development of hardware to improve
processing speed (which plays an important role in the operation
system),
- Modification of the system according to developmental needs of the user. Between 50% to 80%
work performed on most systems development undertaken to
revision, modification, conversion, enhancement and tracking errors.
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Basic Concepts of Information:
Information: data that has been processed into a form that has meaning for the recipient and
may be a fact, a value that is useful. So there is a process of transformation of data
become an information == input - process - output.
Data is the raw material for some information. The difference of information and data is very
depending on the relative value of management that requires a use for. An information
for certain management level could be for management-level data on it, or
otherwise.
Representation of information: information figuratively, for example: binary representation.
Quantity of information: the unit of measure information. Depending on the representation. For
representation
binary unit: bit, byte, word, etc..
Quality of information: the bias against error, because: measurement errors and
collection, failure to follow procedures prmrosesan, loss or data is not
processed, or recording error correction data, error history file / master, error
berfungsian systems lack the processing procedure.
Age of information: when, or until when an information has value / meaning to
users. There informasion condition (refer to the particular point in time) and operating
information (stating a change in a range of time).
Information quality; depends on 3 things, that information must be:
• Accurate, meaningful information should be free from mistakes and not biased or
misleading. Accurate also means that information must clearly reflect masudnya.
• Stay on time, means that information that came at the recipient should not be too late.
• Relevant, means that information menpunyai benefits to the wearer. Relevance
information for each person differ from one another.
Information Value; determined from two things, namely the benefits and costs to get it. One
information said to be worth when its benefits are more effective than the cost
get it. Measurement of the value of information is usually associated with cost analysis
effectiveness or cost benefit.
Information Systems Definition:
An integrated system capable of providing useful information for
users.
Or;
An integrated system or human-machine systems, to provide information to
support operations, management in an organization.
These systems utilize hardware and computer software, manual procedures,
model and database management.
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From the above definition there are some keywords:
1. Computer-based Systems, Man / Machine
- Based computer: computer designers must understand the knowledge and
processing information
- Human machine systems: there is an interaction between man and machine as the manager
as a tool to process information. There is a manual process that must be done
human and automated processes that are by machine. Therefore we need a
procedures / manual system.
2. Integrated data base system
- The use of databases together (sharing) in a data base
management system.
3. Supporting Operations
- The information processed and generated used to support the organization's operations.
The term Information System
= Management Information System
= Information Processing System
= Information Decision System
= Information System.
Everything refers to a computer-based information system designed to
support the operation, management and decision-making functions of an organization.
According to Robert A. Leitch; information system is a system within an organization
which bring together the needs of daily transaction processing, support operations, are
managerial and strategic activities of an organization and provide a specific outside party
with the necessary reports.
Physical Component Information System:
1. Computer hardware: CPU, Storage, device Input / Output, Terminal for
interaction, data communication media
2. Computer software: system software (operating system and utilitinya),
common software applications (programming language), software applications (application
accounting etc.).
3. Databases: storing data on computer storage media.
4. Procedure: step-by-step use of system
5. Personnel for operations management (SDM), includes:
- Clerical personnel (to handle the transaction and processing the data and perform
inquiry = operator);
- First level manager: to manage the data processing is supported with planning,
scheduling, identification of situations out-of-control and decision making levels
lower middle.
- Staff specialist: used for the analysis for planning and reporting.
- Management: for making periodic reports, requests periodicals, special analysis,
Khsusus reports, supporting the identification of problems and opportunities.
Applications = + program operating procedures.
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RELATIONSHIP WITH INFORMATION SYSTEMS MANAGERS
On the one already mentioned that one of the components of the system information is
personnel as the manager of information. Therefore the relationship between information systems
very closely with the managers. System information required depends on the
needs of managers.
Management information systems are organized in a management structure. Therefore
shape / type the necessary information systems in accordance with the level of management.
Top Level Management: strategic planning, policy and decision making.
Manejemen Intermediate Level: for tactical planning.
Manejemen Level Below: for planning and supervision of operations
Operator: for transaction processing and responding to requests.
For the development of an information system necessary organizational management structure
personnel.
Strutktur essentially:
Director of Information Systems
Systems Development Manager
Systems Analyst
Programmer
Computers and Operations manager.
Variations in management structure is very dependent on the Managerial Efficiency vs. User Service.
INFORMATION SYSTEM DESIGN
The design of information systems is the development of new systems from old systems
There, where the problems occur on the old system is expected to be resolved in
the new system.
INFORMATION SYSTEM DEVELOPMENT LIFE CYCLE
(SYSTEM DEVELOPMENT LIFE cycles - SDLC)
Conceptually the development cycle of an information system is as follows:
1. Systems Analysis: analyze and define problems and possible solutions
for information systems and organizational processes.
2. System Design: designing output, input, file structures, programs, procedures,
hardware and software required to support information systems
3. Development and Testing System: building the software needed to
support system and perform testing accurately. Perform installation and testing
of the hardware and operating software
4. System Implementation: switching from the old system to new system, conduct training and
guidance as necessary.
5. Operation and Maintenance: operating system support information and make changes
or additional facilities.
6. Evaluation System: sejauih evaluate where the system has been built and how well
system has been operated.
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The cycle takes place repeatedly. The cycle above is a classic model
of information systems development. New models, such as prototyping, spiral, 4GT and
combination of the classical model developed above.
ANALYSIS SYSTEM
The reason the importance of starting the analysis of the system:
1. Problem-solving: the old system did not function in accordance with needs. For that analysis
necessary to fix the system so it can function as needed.
2. New needs: the need for new in the organization or the environment so that
it is necessary modifications or additional information systems to support
organization.
3. Implement new ideas or technologies.
4. Improve overall system performance.
Limitation of System Analysis:
Activities conducted in the analysis system must be able to answer general questions, as follows:
1. The new system is to be built? or
2. System is to be added or modified on the old system that has been
there?
To that must be answered in detail questions:
1. What information is needed?
2. By whom?
3. When?
4. Where?
5. In what form?
6. How do I get it?
7. Where's he from?
8. How do I collect it?
Proposal conduct systems analysis; Contains:
1. The definition of clear and consistent about the reasons for the analysis
2. The definition limits the analysis to be performed
3. Identify the facts that will be collected and studied for analysis
4. Identify sources where the facts can be obtained
5. Description of goals and constraints that may be in the analysis
6. Projections of possible problems that will occur during the analysis
7. Tentative schedule analysis
The sources of facts that can be studied for system analysis:
1. Existing system
2. Other internal sources: people, documents, and the relationship between those organizations or
function there
3. External sources: interfaces with other systems, seminars, vendors, journals, textbooks and
information or other disciplines that are outside the system
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Analysis Framework:
1. Analysis of the level of decision makers (management organization): analyze
organization, functions and information needs and information generated.
2. Analysis of the flow of information: identifying what information is needed, who
requiring, where it came from.
3. The analysis of input and output.
In this analysis techniques and tools used, al: interview, questionaire, observation,
sampling and document gathering, charting (organization, flow, dfd, ER, OO, etc.), decision
tables and matric
Report the results of the analysis:
Report the results of the analysis must contain:
1. Description of the reason and scope (limitations) analysis
2. Description of existing systems and operations.
3. Description of the purpose (objective) and system constraints
4. The description of the problems and potential problems not resolved
5. A description of the assumptions taken by the system analyst during the analysis process
6. The recommendations of the new system and the need for preliminary design
7. Projected resource requirements and costs are expected to include in the design
new systems or modify it. These projections include eligibility for the
next.
Category aspects of feasibility:
1. Technical Feasibility: the feasibility of hardware and software.
2. Economic Feasibility: are there any advantages or disadvantages, common operational efficiency
organization.
3. Feasibility operations: associated with operating procedures and the people who run
organization
4. Feasibility schedule: can use models such as PERT and scheduling
Gantt Chart. Whether or not feasible development schedule.
The final result analysis system (decision):
1. Stop the job, because the proposal is not feasible.
2. Wait a moment, because there are other considerations.
3. Modification, management decided to modify prososal with other subsystems.
4. Process on the condition, there are eligibility requirements.
5. Process unconditionally, all terms are met. Submissions will be accepted and the process proceeds
to
initial design.
System development cycle according to J. Kelly F.;
1. Research systems
a. Definition of the scope.
b. Research studies
2. Analysis and design of the system
a. Research studies
b. Data collection and analysis
c. System design
d. Implementation plan
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3. System development
a. Development
b. Testing
c. Operation
d. Treatment
System development cycle according to Martin and Thomas Harrel L;
1. Conception system
2. Preliminary analysis
a. Pendefinisan preliminary issues
b. Investigation
c. Preparation of the proposed system
3. System design
a. Detailed analysis
b. Designing a decision
c. Designing target
d. System design
4. Programming
a. Re solve design
b. Develop a flow chart outlines
c. Writing instruction program
d. Assemble a program
e. Preparing data for test
f. Testing
g. Checking results
h. Diagnose faults
i. Correct program
j. Start the system testing
5. Documentation
6. Installing the system
7. Operating system
SYSTEM DESIGN
Analysis system used to answer the question what? While the design used
to answer the question how? The design concentrates on how the system is built
to meet the needs analysis phase.
The elements of knowledge related to the design process:
1. Resource organization: the organization rests on five elements, namely: man, machines,
materials, money and methods.
2. Information needs of users: information obtained from users during the phase
analysis system.
3. System requirements: results of the analysis system.
4. Data processing methods, whether: manual, elektromechanical, puched card, or
computer base.
5. Data operations. There are several basic operations of data, ie: capture, classify, arrange,
summarize,
calculate, store, retrieve, reproduce and disseminate.
6. Design aids, such as: dfd, DCD, dd, decision tables, etc..
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The basic steps in the design process:
1. Defining the purpose of the system (defining the system goal), not only based on information
users, but also a study of abstraction and the overall characteristics
system information needs.
2. Building a conceptual model (develop a conceptual model), a picture
which describes the overall system as a functional unit of the system unit.
3. Applying kendala2 organization (applying organizational contraints). Apply
the constraints of the system to obtain the most optimal system. Organizational elements
is a constraint, while the functions to be optimized is:
performance, reliability, cost, schedule instalation, maintenability, flexibility,
grouwth potential, life expectancy. Models for optimal system can be described
as a model which contains: the needs of system and organizational resources
as input; weighting factor comprises functions optimally at the top, and the total value of the
should be optimized from the weighting factor.
4. Defining the data processing activities (defining data processing activities).
This can be done by defining the approach of input-process-output. To
determine this iterative process is required as follows:
a. Mengidentifikasn output is paramount to support / achieve the objectives of the system
(System's goal)
b. Field lists the specific information needed to provide the output
c. Identify the input data needed to build spesifikik field
necessary information.
d. Describe the data processing operations are applied to process input
be output as needed.
e. Identify elements of input into the input section and stored
during the processing of inputs into outputs.
f. Repeat steps ae continuously served until all the required output is obtained.
g. Build a data base that will support the effectiveness of the system to meet
needs of the system, data processing and data characteristics.
h. Based on system development constraints, priority support, the estimated
cost of development; reduce the input, output and extreme processing
i. Define the various control points to regulate the activities of data processing
determines the general quality of data processing.
j. Complete the input and output format is best for system design.
5. Setting up a system design proposal. This proposal is necessary for the management whether
the next process feasible to proceed or not. Things that need to be prepared in
preparation of this proposal are:
a. Restate the reasons for starting work on the system including
goal / objective specific and related to user needs and design
system.
b. Setting up a simple model however, a comprehensive system that will
filed.
c. Showing all available resources to implement and
care system.
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d. Identify critical assumptions and issues that have not been addressed that may
affect the final system design.
While the format of the design proposal is very berfariasi but contain halhal
above.
Basic Principles of Design
There are two basic principles of design, a.l:
1. Monolithic system design. Emphasis on systems integration. Resource which could
integrated to obtain an effective system, especially in cost.
2. Modular system design. Emphasis on solving the functions that have
low idependensi into modules (functional subsystem) are separated so that
allows us to concentrate on design per module. An information system
can be broken down into seven functional subsystems, ie: data collection, data processing, file
updates, data storage, data retrival, report information and data processing controls.
A general guideline in the design of the functional subsystems of a system of information:
1. Sources of data should be collected only once as an input to the system information.
2. Accuracy of data sources is highly dependent on the number of steps to his records, collect
and prepare data for processing. The fewer steps the more accurate.
3. Data generated from computer-based systems should not be inserted again into
system.
4. Timing necessary to collect data must be smaller than the timing
information is required.
5. Keep the selection means the most optimal data collection
6. Data collection should not be on-line, but depending on the needs of the information.
7. All data sources must be in the validation and edited immediately after the collect.
8. Data is already validated, should not be validated in further processing.
9. Total control must be checked again immediately before and after a processing activity
great done.
10. Data must be stored only in one place in the database unless there is a constraint system.
11. All data fields should have an entry and maintenance procedures.
12. All data must be printed in a format that is meaningful for audit purposes.
13. Transaction file must be at least maintained in a cycle of updates to the database.
14. Backup and security procedures must be provided for all fields of data.
15. Any non-sequential files need to have periodic reorganization procedures.
16. All data fields must have the date of update / access the last save.
To analyze the system effectively, we need more than just a device
modeling; the method. This method changed from time to time in accordance with
technological developments. This cycle tends to repetition significant change with
discovery of the fourth and last generation language in which fifth-generation approach
with object-oriented paradigm and the compatibility between models.
There are basically two methods of approach in building the system, the first of topdown.
In this method the system is derived from the global mapping is then
will decline to a more descriptive. This method is analogous to making
homes starting from the most fundamental aspects of the foundation down to the smallest
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such as a faucet in the bathroom. The second method is bottom-up, where the system
mapped from the smallest unit so that the largest units, such as automobile assembly. On
1980_an early start designing a technique known as structured by using the concept
parallel and cycle, for example between test programs and programming work can be done
parallel, and if there is something wrong when implementation is carried out surveys,
analysis and redesign that replaces the classical method of designing an inclined
serial.
In principle, designing the system as a structured activity covers:
�� Survey; serves to determine user requirements, errors in
the old system, set goals for design, automation systems proposed
feasible and acceptable, and prepare a report containing a survey of all
something, at the points above.
�� analysis system; combine user survey report and policy be
specification using structured modeling.
�� Design; implement the desired model user.
�� Implementation; represents the results of the design into programming.
  The
�� trial design; test the whole structured specifications.
�� Testing end; test the overall system.
�� Description of the procedure; creation of written technical reports and user
operation.
�� Conversion database; convert the data, because the word data is plural in meaning
previous system.

				
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