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INFORMATION SYSTEMBasic Concepts SystemsSystem: a collection of elements that interact to achieve a goalparticular.According to Jerry FithGerald; system is a network of proceduresinterconnected, gathered together to perform an activity oraccomplish a particular goal.System Characteristics:• Have a component;A system consists of several components that interact with each other, working togetherto form a unity. The components of the system can be a subsystemor the parts of the system. Each system no matter however small, alwayscontaining the components or subsystems. Each subsystemhas the properties of the system to perform a particular function andaffect the overall system process. A system can have aa larger system called the supra system, for example a company canreferred to as a system and industry which is a larger system cancalled the supra system. If the industry is seen as a system, thencompanies can be called a subsystem. Similarly, if a company is deemedas a system, then the accounting system are subsystems.• Limit system (boundary);Boundary is an area that limits the system between a system with which systemother or with the environment outside. Boundary system allows a systemviewed as a whole. Boundary of a system indicates the scope (scope)of the system.• The environment outside the system (environment);Is anything outside the limits of the system that affect system operation.• Liaison system (interface);Is a media liaison between one subsystem with another subsystem.• Enter the system (input);Energy is fed into the system. Input can be inputmaintenance (maintenance inputs) and input signal (input signal). Maintenance inputis the energy that is inserted so that the system can operate. Signal inputis the energy that is processed to obtain the output. For example in the systemcomputer, the program is the maintanance inputs used to operatecomputer 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 part of that process 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.2Classification System:• abstract system; system in the form of thoughts or ideas that are not apparentphysical (system of theology)Physical systems; an existing physical system (a computer system, accounting system,production systems, etc..)• Natural Systems; system that occurs through natural processes. (Solar system, outside the systemspace, etc. reproductive system.Man-made systems; system designed by humans.Man-made systems that involve human interaction with machines called humanmachinesystem (eg information systems)• System Specific (deterministic system); operate with existing behaviorcan be predicted. The interaction of the parts can be detected with certainty thatoutput of the system can be predicted (eg computer systems)Indeterminate system (probabilistic system); system that conditions the future can notpredictable because it contains elements of probability.• closed system (closed system); systems that are not related and are not affectedwith external systems. This system works automatically without interferinghand from the outside. Theoretically such systems exist, but in fact nothere is a system that is completely covered, there is only Relatively Closed system (inrelatively closed, not completely closed).Open system (open system); system-related and affected byouter environment.More specifically recognized also called the automated system, which is partof man-made systems and berineraksi with control by one or more computersas part of the system used in modern society.Automated system has several components, namely;
Hardware (CPU, disks, printers, tape).�� software (operating system, database system, communication control program,application program).�� Personnel (who operate the system, providing input, output consumedand perform activities that support manual systems).�� The data (which must be stored in the system during a certain period).�� Procedure (instructions and policies for operating systems.)Automated system is divided into several categories:♦ On-line systems. On-line system is a system that receives direct input on the areawhere inputs are recorded and produce output that can be the resultcomputing in the areas where they are needed. The area itself can be broken inscale, for example, hundreds of kilometers. Usually used for the reservation of air transport,railway reservations, banking, etc..♦ Real-time systems. Real-time system is a mechanism for controlling, recording data,processing is very fast so that the output can be received in timerelatively equal. The difference with on-line system is a unit of time usedreal-time, usually one-hundredth or thousandth of a second on-line while still dalahscale of seconds or even sometimes a few minutes. Another difference, on-line usually3only interact with the user, while real-time interacting directly withuser and the mapped environment.♦ Decision support system + strategic planning system. Systems that process transactionsorganization on a daily basis and help managers make decisions, evaluateand analyze organizational goals. Used for payroll system, the systemreservations, accounting systems and production systems. Normally shaped statistical package,marketing package, etc.. This system not only records and displays the data but alsomathematical functions, statistical analysis of data and display the information in the formgraphics (tables, charts) as a conventional report.♦ Knowledge-based system. Computer programs are made close to the capabilities andknowledge of an expert. Generally use hardware and softwarespecial software such as LISP and PROLOG.Systems based on the basic principle generally divided into:• The system is specialized, is a difficult system on environmental diterakpandifferent (eg systems biology; fish transferred to landline)• large system; is a system that most of its resources to function doDaily care (eg dinosaurs as a biological system spends mostof his life by eating and eating).• System as part of another system, the system is always a part of the systemlarger, and can be divided into smaller systems.• developing systems; although not applicable to all systems but almost allsystem is always evolving.Performer system consists of 7 groups:1. Users;In general, 3 is the type of user, ie operational, supervisory and executive.2. Management;Generally consist of 3 types of management, namely the user in charge of managementaddress use where a new system implemented, the management system involvedin the development of the system itself and the general management involved instrategic planning systems and decision support systems. Groupmanagement is usually involved with decisions relating to people, timeand money, for example;"The system must be capable of performing the functions x, y, z, but it must be developedwithin six months with the involvement of programmers from the department w, withcost of x ".3. Examiner;The size and complexity of the system that worked and the natural form of organization where the systemwas implemented to determine whether or not inspectors conclusions.Examination usually determine things based on standard measuresdeveloped at many similar companies.4. Analyzer systems;Its functions such as:- Archaeologist; namely that explore how the old system was running,how the system is run and all matters relating to the old system.4- Innovators; namely that helped develop and open the user insightfor other possibilities.- Mediators, namely the communication functions of all levels, among otherusers, managers, programmers, inspectors and other system actorsmay not have the attitude and views of the same.- The head of the project; analyzer system should be more experienced personnelfrom the programmer or designer. In addition, given the general system analyzerdetermined in advance in a job before the other work, iswhich is normal if a portion of the work in charge analyzer system.5. The designer of the system;The designer of the system receives the results of analyzer systems in the form that the user needsnot oriented to a particular technology, which is then transformed to designhigh-level architecture and can be formulated by the programmer.6. Programmer;Working in the shape of the design program that has been received from the designer.7. Operating personnel;Duty and responsibility at the center of the computer such as networking, securityhardware, software security, printing and backups. Actors maynot required when the system is running is not great and does not require classificationspecifically to run the system.The basic point in the development systemAnalyser system is part of a team that works to develop a systemhas high efficiency and meet the needs of end users. This developmentinfluenced by a number of things, namely:• Productivity, the current system is needed for more, better and faster.This requires more programmer and analyzer system quality,extra working conditions, the ability of users to float its own, languagebetter programming, better system maintenance (generally 50% to70% of resources are used for system maintenance), use of technical disciplinesoftware and automated systems development.• Reliability, time spent testing the system in general spend50% of total system development time.Within 30 years a number of systems used in different companiesexperienced an error and ironically is not easy to change it. If thereerrors, there are two ways you can do is to do source trackingerror and must find a way to correct these errors withreplace the program, eliminating a number of long statement or adda new statement.• Maintabilitas, nursing covers;- Modifications to fit the development of hardware systems to improveprocessing speed (which plays an important role in the operationsystem),- Modification of the system according to the development needs of the user. Between 50% to 80%work performed on most systems development undertaken torevision, modification, conversion, improvement and tracking error.5Basic Concept of Information:Information: data that has been processed into a form that has meaning for the recipient andcan be a fact, a value that is useful. So there is a data transformation processbecome an information == input - process - output.Data is the raw material for the information. Differences of information and data isrelative depending on the value of use for management that need. An informationfor certain management-level data for management can be a level above it, orvice versa.Representation of information: information figuratively, for example: binary representation.The quantity of information: the unit of measure information. Depending on the representation. For representationbinary unit: bit, byte, word, etc..Quality of information: the bias against error, because: error measurement andcollection, failure to follow procedures prmrosesan, lost or no dataprocessed, or recording error correction data, error history file / master, errorprocessing procedure non disabling the system.Age of information: when or how long an information has value / meaning forusers. There informasion condition (refer to the particular point in time) and operatinginformation (stating a change in a range of time).Information quality; depends on 3 things, that information must:• Accurate, meaningful information should be free from mistakes and not biased ormisleading. Accurate also means that information must clearly reflect masudnya.• Stay on time, means the information that came at the recipient should not be too late.• Relevant, means that information should be entitled benefits to the wearer. Relevanceinformation for each person differ from one another.Information Value; determined from two things, namely the benefits and costs to get it. Ainformation said to be worth more effective if its benefits compared to costsget it. Measuring the value of information is usually associated with cost analysiseffectiveness or cost benefit.Information Systems Definition:An integrated system that can provide useful information forusers.Or;An integrated system or human-machine system, to provide information forsupport the operation, management within an organization.These systems utilize hardware and computer software, manual procedures,management model and database.6From the above definition there are some keywords:1. Computer-based Systems and Human / Machine- Based computer: the designer must understand the knowledge of computer andinformation processing- Human Systems machines: there is interaction between humans and machines to manageas a tool to process information. There is a manual process that must be donehumans and there is an automated process by machine. Therefore we need aprocedure / manual system.2. Integrated database system- The use of databases together (sharing) in a data basemanagement system.3. Support Operations- Information that is 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 tosupport the operation, management and decision-making functions of an organization.According to Robert A. Leitch; information system is a system in an organizationwhich bring together the needs of daily transaction processing, support operations, aremanagerial and strategic activities of an organization and provide a specific outside partywith the necessary reports.Physical Component Information System:1. Computer hardware: CPU, Storage, device Input / Output, Terminal forinteraction, data communication media2. Computer software: system software (operating system and utilitinya)common software applications (programming language), software applications (applicationaccounting etc.).3. Databases: storing data on computer storage media.4. Procedure: step-by-step use of system5. Personnel for operations management (SDM), includes:- Clerical personnel (for handling and processing transaction data and performinquiry = operator);- First level manager: to manage the data processing is supported with planning,scheduling, identification of situations out-of-control and decision making levelslower middle.- Staff specialist: used for the analysis for planning and reporting.- Management: for making periodic reports, requests khsus, special analysis,khsusus report, supporting the identification of problems and opportunities.Applications = program + operating procedures.7RELATIONS WITH MANAGEMENT INFORMATION SYSTEMIn part 1 already mentioned that one of the components of information systems ispersonnel as managers of information. Therefore, the relationship between information systemsvery closely with the managers. System information required depends on theneeds of managers.Management information system organized in a management structure. Thereforeshape / type of system the necessary information in accordance with the level of management.Top Level Management: strategic planning, policy and decision making.Medium Level management: for tactical planning.Lower level management: for planning and monitoring operationsOperator: for transaction processing and responding to requests.For the development of an information system necessary organizational management structurepersonnel.Strutktur basically:Director of Information SystemsSystems Development ManagerSystems AnalystProgrammerComputers and Operations managers.The variation of the management structure is very dependent on Managerial Efficiency vs. User Service.INFORMATION SYSTEM DESIGNThe design of information systems is the development of new systems from old systemsThere, where the problems occurred in the old system is expected to be resolved inthe new system.INFORMATION SYSTEM DEVELOPMENT LIFE CYCLE(SYSTEM DEVELOPMENT LIFE cycles - SDLC)Conceptually an information system development cycle is as follows:1. Systems Analysis: analyze and define problems and possible solutionsfor information systems and organizational processes.2. System Design: designing output, input, file structure, programs, procedures,hardware and software needed to support information systems3. Development and Testing System: build the necessary software tosupport systems and perform accurate testing. Perform installation and testingof the hardware and operating software4. System Implementation: switch from the old system to new system, conduct training andguidance as necessary.5. Operation and Maintenance: support the operation of information systems and make changesor additional facilities.6. System Evaluation: evaluate sejauih where the system has been built and how wellsystem has been operated.8The cycle takes place repeatedly. The cycle represents the classical modelof information systems development. New models, such as prototyping, spiral, 4GT andcombination of the classical model developed above.ANALYSIS SYSTEMThe reason for the importance of beginning the analysis of systems:1. Problem-solving: the old system was not functioning as required. For that analysisnecessary to fix the system so it can function as needed.2. New needs: the need for new in the organization or environment so thatrequired any modifications or additional information systems to supportorganization.3. Implementing 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? or2. The system is to be added or modified on the old system that alreadythere?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 did it come from?8. How do I collect?Proposal conduct systems analysis; Contains:1. The definition is clear and consistent about the reasons for the analysis2. The definition limits the analysis to be performed3. Identify the facts that will be collected and studied during the analysis4. Identify sources where the facts can be obtained5. Description of objectives and constraints that may be in the analysis6. Projection of potential problems that will occur during the analysis7. Schedule tentative analysisThe sources of facts that can be learned for the analysis of the system:1. Existing system2. Other internal sources: people, documents, and the relationship between those organizations orthere are functions3. External Source: interface with other systems, seminars, vendors, journals, textbooks andinformation or other sciences which are outside the system9Analysis Framework:1. Analysis of levels of decision makers (management organization): analysisorganization, functions and information required and the information generated.2. Analysis of the flow of information: identifying what information is needed, whorequiring, where it comes from.3. Analysis of input and output.In this analysis techniques and tools used, ie: interview, questionaire, observation,sampling and document gathering, charting (organization, flow, dfd, ER, OO, etc.), decisiontables and metricsReport the results of the analysis:Report the results of the analysis must contain:1. Description of the reason and scope (limitations) analysis2. Description of existing systems and operations.3. Description of the purpose (objective) and the constraint system4. The description of the problems and potential problems not resolved5. A description of the assumptions taken by the system analyst during the analysis process6. The recommendations that the new system and the need for preliminary design7. Projection of resource requirements and costs are expected to include in the designnew systems or modify them. These projections include eligibility for the processnext.Categories aspects of feasibility:1. Technical feasibility: the feasibility of hardware and software.2. Economic feasibility: whether there are gains or losses, unusual operational efficiencyorganization.3. Feasibility surgery: associated with operating procedures and the people who runorganization4. Feasibility schedule: to use models such as PERT and schedulingGantt Chart. Whether or not feasible development schedule.The final result of the analysis system (decision):1. Stop the job, because the proposal is not feasible.2. Wait a moment, because there are still other considerations.3. Modification, management decided to modify prososal with other subsystems.4. Process with the terms, there eligibility requirements.5. Process unconditionally, all requirements are met. Submissions will be accepted and the process continues intooriginal design.System development cycle by J. F. Kelly;1. Research systemsa. Definition of the scope.b. Research Studies2. Analysis and design of the systema. Research Studiesb. Data collection and analysisc. Design systemd. Plan implementation103. Development systema. Developmentb. Testingc. Operationd. TreatmentSystem development cycle according to Martin L. and Thomas Harrel;1. Conception system2. Preliminary Analysisa. Pendefinisan preliminary issuesb. Investigationc. Preparation of the proposed system3. Design systema. Detailed Analysisb. Designing decisionc. Designing targetd. System design4. Programminga. Solving back designb. Develop an outline flowchartc. Writing instruction programd. Assembling programse. Preparing data for testf. Testingg. Checking resultsh. Diagnose faultsi. Repair programj. Starting the testing system5. Documentation6. Installation system7. Operating systemDESIGN SYSTEMThe analysis system used to answer the question what? While the design usedto answer the question how? The design concentrates on how the system is builtto meet the needs analysis phase.The elements of knowledge related to the design process:1. Organizational resources: based on 5 elements of the organization, namely: man, machines,material, money and methods.2. The information needs of users: information obtained from users during the phasesystems analysis.3. System requirements: results of the analysis system.4. Data processing methods, whether: manual, elektromechanical, puched card, orcomputer base.5. Operating data. There are some basic operations of data, ie: capture, classify, arrange, summarize,calculate, store, retrieve, reproduce and disseminate.6. Design tools, such as: dfd, DCD, dd, decision tables, etc..11The basic steps in the design process:1. Defining the purpose of the system (defining the system goal), not only based on informationusers, but also a study of abstraction and the overall characteristicssystem information needs.2. Building a conceptual model (develop a conceptual model), a pictureoverall system that describes the functional unit as the unit system.3. Applying kendala2 organization (applying organizational contraints). Applysystem constraints to obtain the most optimal system. Organizational elementsis a constraint, while the functions that must be optimized are:performance, reliability, cost, schedule instalation, maintenability, flexibility,grouwth potential, life expectancy. Models for optimal system can be describedas a model that contains: the need for system and organizational resourcesas input; weighting factor consists of the functions above optimal, and the total valueshould be optimized from the weight factor.4. Defining a data processing activities (defining data processing activities).This can be done by defining the approach of input-process-output. Fordetermine this requires an iterative process as follows:a. Mengidentifikasn most important output to support / achieve the goal system(System's goal)b. It lists the specific fields of information needed to provide these outputsc. Identify spesifikik data input required to build fieldrequired information.d. Describe the data processing operations are applied to process inputoutput should be required.e. Identify the input element to be input and stored partsduring the processing of inputs into outputs.f. Repeat steps ae continuously till all the required output is obtained.g. Build databases that will support the effectiveness of the system to meetsystem requirements, how data processing and data characteristics.h. Based on the constraints on system development, priority support, the estimatedcost of development; reduce the input, output and processing the extremei. Define the various control points to regulate the activities of data processingdetermine the general quality of data processing.j. Complete the input and output format is best for system design.5. Prepare a proposal system design. This proposal is necessary for the management whetherthe next process feasible to proceed or not. Things that need to be prepared inpreparation of this proposal are:a. Restate the reasons for the commencement of work the system includingpurpose / specific objective and related to user needs and designsystem.b. Setting up a simple model however, a comprehensive system that willproposed.c. Showing all available resources to implement andcare system.12d. Identify critical assumptions and issues that might not resolvedaffect the final system design.While the format of the design proposal is very berfariasi but contain thingsabove.Basic Principles of DesignThere are 2 basic principles of design, a.l:1. Design of monolithic systems. Emphasis on systems integration. Resource which can beintegrated to obtain an effective system, especially in cost.2. Modular system design. Emphasis on solving the functions that haveLow idependensi into modules (functional subsystem) so that separateallows us to concentrate on design per module. An information systemcan be broken down into seven functional subsystems, ie: data collection, data processing, fileupdates, data storage, data retrival, information reports and data processing controls.A general guideline in the design of a functional subsystem of a system of information:1. Sources of data should be collected only once as an input to information systems.2. Accuracy of data sources is highly dependent on the number of steps to his records, collectand prepare data for processing. The fewer steps the more accurate.3. Data generated from computer-based system should not be inserted again intosystem.4. Timing necessary to collect data must be smaller than the timinginformation will be needed.5. Keep the selection means the most optimal data collection6. Data collection did not have on-line, but depending on the needs of information.7. All data sources should be in the validation and edited immediately after the gather.8. Data that has been validated, should not be validated in further processing.9. Total control must be checked again before and after a processing activitygreat done.10. Data must be stored only in 1 place in the database unless there is a constraint system.11. All fields should have data 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 field data.15. Any non-sequential files need to have periodic reorganization procedures.16. All data fields must have the date of update / access to storage last.To analyze the system effectively, we need more than just a devicemodeling, which is the method. This method changed from time to time in accordance withtechnological developments. This cycle tends menglami significant change withdiscovery of a fourth-generation language fifth and last generation where the approachwith object-oriented paradigm and the compatibility between models.There are basically two methods of approach in building the system, the first of which is topdown.In this method the system derived from the global mapping is thenwill be reduced to a more descriptive. This method is analogous to the creationhome that starts from the most fundamental aspect that is the foundation down to the smallest
such as a faucet in the bathroom. The second method is bottom-up, where the systemmapped from the smallest unit so that the largest unit, such as automobile assembly. Inearly 1980_an becoming known techniques by using the concept of designing structuredparallel and cycle, for example between test programs and programming work can be doneparallel, and if there is something wrong when implementing the survey,analysis and redesign that replaces the classical method of designing that tends toserial.In principle, the design activities in a structured system covers:Survey; function to determine the needs of users, the errors inold system, set design goals, proposed automation systemfeasible and acceptable, and prepare a report containing a survey of allsomething, the points above.
Hardware (CPU, disks, printers, tape).�� software (operating system, database system, communication control program,application program).�� Personnel (who operate the system, providing input, output consumedand perform activities that support manual systems).�� The data (which must be stored in the system during a certain period).�� Procedure (instructions and policies for operating systems.)Automated system is divided into several categories:♦ On-line systems. On-line system is a system that receives direct input on the areawhere inputs are recorded and produce output that can be the resultcomputing in the areas where they are needed. The area itself can be broken inscale, for example, hundreds of kilometers. Usually used for the reservation of air transport,railway reservations, banking, etc..♦ Real-time systems. Real-time system is a mechanism for controlling, recording data,processing is very fast so that the output can be received in timerelatively equal. The difference with on-line system is a unit of time usedreal-time, usually one-hundredth or thousandth of a second on-line while still dalahscale of seconds or even sometimes a few minutes. Another difference, on-line usually3only interact with the user, while real-time interacting directly withuser and the mapped environment.♦ Decision support system + strategic planning system. Systems that process transactionsorganization on a daily basis and help managers make decisions, evaluateand analyze organizational goals. Used for payroll system, the systemreservations, accounting systems and production systems. Normally shaped statistical package,marketing package, etc.. This system not only records and displays the data but alsomathematical functions, statistical analysis of data and display the information in the formgraphics (tables, charts) as a conventional report.♦ Knowledge-based system. Computer programs are made close to the capabilities andknowledge of an expert. Generally use hardware and softwarespecial software such as LISP and PROLOG.Systems based on the basic principle generally divided into:• The system is specialized, is a difficult system on environmental diterakpandifferent (eg systems biology; fish transferred to landline)• large system; is a system that most of its resources to function doDaily care (eg dinosaurs as a biological system spends mostof his life by eating and eating).• System as part of another system, the system is always a part of the systemlarger, and can be divided into smaller systems.• developing systems; although not applicable to all systems but almost allsystem is always evolving.Performer system consists of 7 groups:1. Users;In general, 3 is the type of user, ie operational, supervisory and executive.2. Management;Generally consist of 3 types of management, namely the user in charge of managementaddress use where a new system implemented, the management system involvedin the development of the system itself and the general management involved instrategic planning systems and decision support systems. Groupmanagement is usually involved with decisions relating to people, timeand money, for example;"The system must be capable of performing the functions x, y, z, but it must be developedwithin six months with the involvement of programmers from the department w, withcost of x ".3. Examiner;The size and complexity of the system that worked and the natural form of organization where the systemwas implemented to determine whether or not inspectors conclusions.Examination usually determine things based on standard measuresdeveloped at many similar companies.4. Analyzer systems;Its functions such as:- Archaeologist; namely that explore how the old system was running,how the system is run and all matters relating to the old system.4- Innovators; namely that helped develop and open the user insightfor other possibilities.- Mediators, namely the communication functions of all levels, among otherusers, managers, programmers, inspectors and other system actorsmay not have the attitude and views of the same.- The head of the project; analyzer system should be more experienced personnelfrom the programmer or designer. In addition, given the general system analyzerdetermined in advance in a job before the other work, iswhich is normal if a portion of the work in charge analyzer system.5. The designer of the system;The designer of the system receives the results of analyzer systems in the form that the user needsnot oriented to a particular technology, which is then transformed to designhigh-level architecture and can be formulated by the programmer.6. Programmer;Working in the shape of the design program that has been received from the designer.7. Operating personnel;Duty and responsibility at the center of the computer such as networking, securityhardware, software security, printing and backups. Actors maynot required when the system is running is not great and does not require classificationspecifically to run the system.The basic point in the development systemAnalyser system is part of a team that works to develop a systemhas high efficiency and meet the needs of end users. This developmentinfluenced by a number of things, namely:• Productivity, the current system is needed for more, better and faster.This requires more programmer and analyzer system quality,extra working conditions, the ability of users to float its own, languagebetter programming, better system maintenance (generally 50% to70% of resources are used for system maintenance), use of technical disciplinesoftware and automated systems development.• Reliability, time spent testing the system in general spend50% of total system development time.Within 30 years a number of systems used in different companiesexperienced an error and ironically is not easy to change it. If thereerrors, there are two ways you can do is to do source trackingerror and must find a way to correct these errors withreplace the program, eliminating a number of long statement or adda new statement.• Maintabilitas, nursing covers;- Modifications to fit the development of hardware systems to improveprocessing speed (which plays an important role in the operationsystem),- Modification of the system according to the development needs of the user. Between 50% to 80%work performed on most systems development undertaken torevision, modification, conversion, improvement and tracking error.5Basic Concept of Information:Information: data that has been processed into a form that has meaning for the recipient andcan be a fact, a value that is useful. So there is a data transformation processbecome an information == input - process - output.Data is the raw material for the information. Differences of information and data isrelative depending on the value of use for management that need. An informationfor certain management-level data for management can be a level above it, orvice versa.Representation of information: information figuratively, for example: binary representation.The quantity of information: the unit of measure information. Depending on the representation. For representationbinary unit: bit, byte, word, etc..Quality of information: the bias against error, because: error measurement andcollection, failure to follow procedures prmrosesan, lost or no dataprocessed, or recording error correction data, error history file / master, errorprocessing procedure non disabling the system.Age of information: when or how long an information has value / meaning forusers. There informasion condition (refer to the particular point in time) and operatinginformation (stating a change in a range of time).Information quality; depends on 3 things, that information must:• Accurate, meaningful information should be free from mistakes and not biased ormisleading. Accurate also means that information must clearly reflect masudnya.• Stay on time, means the information that came at the recipient should not be too late.• Relevant, means that information should be entitled benefits to the wearer. Relevanceinformation for each person differ from one another.Information Value; determined from two things, namely the benefits and costs to get it. Ainformation said to be worth more effective if its benefits compared to costsget it. Measuring the value of information is usually associated with cost analysiseffectiveness or cost benefit.Information Systems Definition:An integrated system that can provide useful information forusers.Or;An integrated system or human-machine system, to provide information forsupport the operation, management within an organization.These systems utilize hardware and computer software, manual procedures,management model and database.6From the above definition there are some keywords:1. Computer-based Systems and Human / Machine- Based computer: the designer must understand the knowledge of computer andinformation processing- Human Systems machines: there is interaction between humans and machines to manageas a tool to process information. There is a manual process that must be donehumans and there is an automated process by machine. Therefore we need aprocedure / manual system.2. Integrated database system- The use of databases together (sharing) in a data basemanagement system.3. Support Operations- Information that is 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 tosupport the operation, management and decision-making functions of an organization.According to Robert A. Leitch; information system is a system in an organizationwhich bring together the needs of daily transaction processing, support operations, aremanagerial and strategic activities of an organization and provide a specific outside partywith the necessary reports.Physical Component Information System:1. Computer hardware: CPU, Storage, device Input / Output, Terminal forinteraction, data communication media2. Computer software: system software (operating system and utilitinya)common software applications (programming language), software applications (applicationaccounting etc.).3. Databases: storing data on computer storage media.4. Procedure: step-by-step use of system5. Personnel for operations management (SDM), includes:- Clerical personnel (for handling and processing transaction data and performinquiry = operator);- First level manager: to manage the data processing is supported with planning,scheduling, identification of situations out-of-control and decision making levelslower middle.- Staff specialist: used for the analysis for planning and reporting.- Management: for making periodic reports, requests khsus, special analysis,khsusus report, supporting the identification of problems and opportunities.Applications = program + operating procedures.7RELATIONS WITH MANAGEMENT INFORMATION SYSTEMIn part 1 already mentioned that one of the components of information systems ispersonnel as managers of information. Therefore, the relationship between information systemsvery closely with the managers. System information required depends on theneeds of managers.Management information system organized in a management structure. Thereforeshape / type of system the necessary information in accordance with the level of management.Top Level Management: strategic planning, policy and decision making.Medium Level management: for tactical planning.Lower level management: for planning and monitoring operationsOperator: for transaction processing and responding to requests.For the development of an information system necessary organizational management structurepersonnel.Strutktur basically:Director of Information SystemsSystems Development ManagerSystems AnalystProgrammerComputers and Operations managers.The variation of the management structure is very dependent on Managerial Efficiency vs. User Service.INFORMATION SYSTEM DESIGNThe design of information systems is the development of new systems from old systemsThere, where the problems occurred in the old system is expected to be resolved inthe new system.INFORMATION SYSTEM DEVELOPMENT LIFE CYCLE(SYSTEM DEVELOPMENT LIFE cycles - SDLC)Conceptually an information system development cycle is as follows:1. Systems Analysis: analyze and define problems and possible solutionsfor information systems and organizational processes.2. System Design: designing output, input, file structure, programs, procedures,hardware and software needed to support information systems3. Development and Testing System: build the necessary software tosupport systems and perform accurate testing. Perform installation and testingof the hardware and operating software4. System Implementation: switch from the old system to new system, conduct training andguidance as necessary.5. Operation and Maintenance: support the operation of information systems and make changesor additional facilities.6. System Evaluation: evaluate sejauih where the system has been built and how wellsystem has been operated.8The cycle takes place repeatedly. The cycle represents the classical modelof information systems development. New models, such as prototyping, spiral, 4GT andcombination of the classical model developed above.ANALYSIS SYSTEMThe reason for the importance of beginning the analysis of systems:1. Problem-solving: the old system was not functioning as required. For that analysisnecessary to fix the system so it can function as needed.2. New needs: the need for new in the organization or environment so thatrequired any modifications or additional information systems to supportorganization.3. Implementing 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? or2. The system is to be added or modified on the old system that alreadythere?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 did it come from?8. How do I collect?Proposal conduct systems analysis; Contains:1. The definition is clear and consistent about the reasons for the analysis2. The definition limits the analysis to be performed3. Identify the facts that will be collected and studied during the analysis4. Identify sources where the facts can be obtained5. Description of objectives and constraints that may be in the analysis6. Projection of potential problems that will occur during the analysis7. Schedule tentative analysisThe sources of facts that can be learned for the analysis of the system:1. Existing system2. Other internal sources: people, documents, and the relationship between those organizations orthere are functions3. External Source: interface with other systems, seminars, vendors, journals, textbooks andinformation or other sciences which are outside the system9Analysis Framework:1. Analysis of levels of decision makers (management organization): analysisorganization, functions and information required and the information generated.2. Analysis of the flow of information: identifying what information is needed, whorequiring, where it comes from.3. Analysis of input and output.In this analysis techniques and tools used, ie: interview, questionaire, observation,sampling and document gathering, charting (organization, flow, dfd, ER, OO, etc.), decisiontables and metricsReport the results of the analysis:Report the results of the analysis must contain:1. Description of the reason and scope (limitations) analysis2. Description of existing systems and operations.3. Description of the purpose (objective) and the constraint system4. The description of the problems and potential problems not resolved5. A description of the assumptions taken by the system analyst during the analysis process6. The recommendations that the new system and the need for preliminary design7. Projection of resource requirements and costs are expected to include in the designnew systems or modify them. These projections include eligibility for the processnext.Categories aspects of feasibility:1. Technical feasibility: the feasibility of hardware and software.2. Economic feasibility: whether there are gains or losses, unusual operational efficiencyorganization.3. Feasibility surgery: associated with operating procedures and the people who runorganization4. Feasibility schedule: to use models such as PERT and schedulingGantt Chart. Whether or not feasible development schedule.The final result of the analysis system (decision):1. Stop the job, because the proposal is not feasible.2. Wait a moment, because there are still other considerations.3. Modification, management decided to modify prososal with other subsystems.4. Process with the terms, there eligibility requirements.5. Process unconditionally, all requirements are met. Submissions will be accepted and the process continues intooriginal design.System development cycle by J. F. Kelly;1. Research systemsa. Definition of the scope.b. Research Studies2. Analysis and design of the systema. Research Studiesb. Data collection and analysisc. Design systemd. Plan implementation103. Development systema. Developmentb. Testingc. Operationd. TreatmentSystem development cycle according to Martin L. and Thomas Harrel;1. Conception system2. Preliminary Analysisa. Pendefinisan preliminary issuesb. Investigationc. Preparation of the proposed system3. Design systema. Detailed Analysisb. Designing decisionc. Designing targetd. System design4. Programminga. Solving back designb. Develop an outline flowchartc. Writing instruction programd. Assembling programse. Preparing data for testf. Testingg. Checking resultsh. Diagnose faultsi. Repair programj. Starting the testing system5. Documentation6. Installation system7. Operating systemDESIGN SYSTEMThe analysis system used to answer the question what? While the design usedto answer the question how? The design concentrates on how the system is builtto meet the needs analysis phase.The elements of knowledge related to the design process:1. Organizational resources: based on 5 elements of the organization, namely: man, machines,material, money and methods.2. The information needs of users: information obtained from users during the phasesystems analysis.3. System requirements: results of the analysis system.4. Data processing methods, whether: manual, elektromechanical, puched card, orcomputer base.5. Operating data. There are some basic operations of data, ie: capture, classify, arrange, summarize,calculate, store, retrieve, reproduce and disseminate.6. Design tools, such as: dfd, DCD, dd, decision tables, etc..11The basic steps in the design process:1. Defining the purpose of the system (defining the system goal), not only based on informationusers, but also a study of abstraction and the overall characteristicssystem information needs.2. Building a conceptual model (develop a conceptual model), a pictureoverall system that describes the functional unit as the unit system.3. Applying kendala2 organization (applying organizational contraints). Applysystem constraints to obtain the most optimal system. Organizational elementsis a constraint, while the functions that must be optimized are:performance, reliability, cost, schedule instalation, maintenability, flexibility,grouwth potential, life expectancy. Models for optimal system can be describedas a model that contains: the need for system and organizational resourcesas input; weighting factor consists of the functions above optimal, and the total valueshould be optimized from the weight factor.4. Defining a data processing activities (defining data processing activities).This can be done by defining the approach of input-process-output. Fordetermine this requires an iterative process as follows:a. Mengidentifikasn most important output to support / achieve the goal system(System's goal)b. It lists the specific fields of information needed to provide these outputsc. Identify spesifikik data input required to build fieldrequired information.d. Describe the data processing operations are applied to process inputoutput should be required.e. Identify the input element to be input and stored partsduring the processing of inputs into outputs.f. Repeat steps ae continuously till all the required output is obtained.g. Build databases that will support the effectiveness of the system to meetsystem requirements, how data processing and data characteristics.h. Based on the constraints on system development, priority support, the estimatedcost of development; reduce the input, output and processing the extremei. Define the various control points to regulate the activities of data processingdetermine the general quality of data processing.j. Complete the input and output format is best for system design.5. Prepare a proposal system design. This proposal is necessary for the management whetherthe next process feasible to proceed or not. Things that need to be prepared inpreparation of this proposal are:a. Restate the reasons for the commencement of work the system includingpurpose / specific objective and related to user needs and designsystem.b. Setting up a simple model however, a comprehensive system that willproposed.c. Showing all available resources to implement andcare system.12d. Identify critical assumptions and issues that might not resolvedaffect the final system design.While the format of the design proposal is very berfariasi but contain thingsabove.Basic Principles of DesignThere are 2 basic principles of design, a.l:1. Design of monolithic systems. Emphasis on systems integration. Resource which can beintegrated to obtain an effective system, especially in cost.2. Modular system design. Emphasis on solving the functions that haveLow idependensi into modules (functional subsystem) so that separateallows us to concentrate on design per module. An information systemcan be broken down into seven functional subsystems, ie: data collection, data processing, fileupdates, data storage, data retrival, information reports and data processing controls.A general guideline in the design of a functional subsystem of a system of information:1. Sources of data should be collected only once as an input to information systems.2. Accuracy of data sources is highly dependent on the number of steps to his records, collectand prepare data for processing. The fewer steps the more accurate.3. Data generated from computer-based system should not be inserted again intosystem.4. Timing necessary to collect data must be smaller than the timinginformation will be needed.5. Keep the selection means the most optimal data collection6. Data collection did not have on-line, but depending on the needs of information.7. All data sources should be in the validation and edited immediately after the gather.8. Data that has been validated, should not be validated in further processing.9. Total control must be checked again before and after a processing activitygreat done.10. Data must be stored only in 1 place in the database unless there is a constraint system.11. All fields should have data 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 field data.15. Any non-sequential files need to have periodic reorganization procedures.16. All data fields must have the date of update / access to storage last.To analyze the system effectively, we need more than just a devicemodeling, which is the method. This method changed from time to time in accordance withtechnological developments. This cycle tends menglami significant change withdiscovery of a fourth-generation language fifth and last generation where the approachwith object-oriented paradigm and the compatibility between models.There are basically two methods of approach in building the system, the first of which is topdown.In this method the system derived from the global mapping is thenwill be reduced to a more descriptive. This method is analogous to the creationhome that starts from the most fundamental aspect that is the foundation down to the smallest
such as a faucet in the bathroom. The second method is bottom-up, where the systemmapped from the smallest unit so that the largest unit, such as automobile assembly. Inearly 1980_an becoming known techniques by using the concept of designing structuredparallel and cycle, for example between test programs and programming work can be doneparallel, and if there is something wrong when implementing the survey,analysis and redesign that replaces the classical method of designing that tends toserial.In principle, the design activities in a structured system covers:Survey; function to determine the needs of users, the errors inold system, set design goals, proposed automation systemfeasible and acceptable, and prepare a report containing a survey of allsomething, the points above.
