security for your computer

We use computer to perform several task in our daily life. They are used to process and store valuable information. Some information may be very important to organization. The loss of these important data can cause serious damage to the organization. It takes lots of money and effort to recover them. As the computer system is delicate electronic and electro mechanical system. It should be used and kept safely. If we do not use it properly, its hardware as well as software, may damage any time. Hence, computer security plays a vital role to the growth and survival of any organization. So, proper management of computer is essential for every organization.

Computer security includes the policies, procedures, tools and techniques designed to protect a company’s computer assets from accidental, international or natural disasters, including accidental input our output errors, theft, breaking or physical damage and illegal access or manipulation of data.

The protection of computer system from accidental or intentional harm, including destruction of computer hardware and software, physical loss of data, deception of computer users and the deliberate invasion of database by unauthorized individuals is called computer security. In other words, the protection of computer, its accessories, data and programs for a long life of computer system is known as computer security.Computer security is concerned with the hardware security as well as software security.

HARDWARE SECURITY

Hardware is the essential part of computer system. Computer can not perform any task without hardware. All the physical parts of the computer such as CPU, Mouse, Monitor, Keyboard, Printer etc are known as hardware. Without existence of hardware software is useless. Hardware plays very important role for proper functioning of our computer system. So, we must check and maintain hardware components frequently. We should replace defective parts of hardware immediately. Now-a-days, hardware diagnostic facilities are

available to find defective hardware comments of the computer system.The protection of al l hardware components used in computer system is known as hardware security.

Some common hardware security measures are as follows:

I. Regular Maintenance

II. Insurance

III. Dust free environment

IV. Protection from fire

V. Protection from theft

VI. Air Condition System

VII. Power Protection Devices (UPS, Volt Gu

ard and Spike Guard)

VIII. Avoiding unrelated persons in the computer rooms.

REGULAR MAINTENANCE

Regular maintenance is necessary for proper functioning of our computer system. We should clean our computer and its peripherals regularly by using dust cleaner. We should scan hard disk using latest and updated Anti-virus software to make it virus free. We should format hard disk time to time in order to make our computer system fast. It is better to delete unnecessary files from hard disk. Upgrade some hardware components as well as software to make computer system fast.

INSURANCE

The term Insurance is not new for us. Generally people insurer their health, life, company, building, vehicle, etc. But nowadays many people also insure their computer. If our computer is damaged or lost we can claim for the insurance amount and replace the computer system easily. So, it is being one of the hardware security measures of our computer.

DUST FREE

Dust is one of the major factors which cause infection of our computer system. Dust effect external as well as internal parts of our computer system. So we should keep our computer in the dust free place. We should use dust cover to prevent our computer from dust.

PROTECTION FROM FIRE

Fire is another factor, which cause infection of our computer system. Fire can damage whole computer system. It is very dangerous factor so we must be very careful about fire. It may cause by smoking, so it is better to avoid smoking inside computer room. Another chance is by electricity so proper wining is necessary inside the computer room. Keeping fire extinguishers can be a good idea.

PROTECTION FROM THEFT

As we all know that computer is an expensive machine as compared to other common machines. So we must keep our computer system in the secure place to protect from theft. If we are not careful, someone can easily state important parts of computer system from computer room. We must lock doors of computer room properly. The entry and exit of computer room must be well controlled and monitored. Unknown or unauthorized persons should not be allowed inside the computer room. Construct the computer room with emergency doors and windows. We can hire security guards to guard computer room.

AIR CONDITION SYSTEM

We should maintain suitable temperature and circulation of air in the computer room. Low or high temperature in the computer system may cause unexpected crashes during the operation of computer. Heat can break down contracts or junctions in the chip or other devices. So, there should be proper air condition to maintain suitable temperature in the computer system. Similarly there should be enough light in the computer room. We can use cooler or fan to prevent heat built-up.

POWER PROTECTION DEVICES

The computer system is made of delicate electronic and electro-mechanical components. We all know that it needs electric power to operate. It needs 220-240 Volts (AC) and the frequency of AC should be 49.5 Hz to 50Hz. High voltage or fluctuating voltage may cause several hardware damage. Our important data and programs can be lost due to sudden power failure. To avoid such unpredictable behavior of the power supply, we have to use some kind of power protecting devices. Some power protection devices are:

I. Uninterruptible Power Supply (UPS)

II. Volt Guard

III. Spike Guard

UPS

A computer needs a well regulated power supply for the proper functioning of its various parts. UPS is a device that stores electricity and automatically provides backup power to the computer in case of electricity failure is the source. It is activated when it detects a loss of power from the source and prevents loss of data and damage of computer parts that might be caused due sudden power failure. It also prevents our computer system against sudden power surge. It acts like a buffer between the incoming power supply and the computer system. It constantly monitors the quality and characteristics of the power supply. Nowadays a several different types of UPS having different capacities are available in the market. We should buy UPS from a well-known and reputable company.

VOLT GUARD

Volt Guard is another important power protection device. It provides constant output voltage to the computer system in case of high input voltage coming from the source. As we have known that our computer system needs voltage between 220 to 240volts and high or low voltage affects our computer system. Volt Guard plays important role to save our computer system from damage due to high voltage. If the input voltage comes from the source, it provides constant output voltage between the ranges 220 to 240 volts. So, we must use Volt Guard in our computer system.

SPIKE GUARD

The lightening in the rainy season can cause sudden increase in the voltage level of the AC-line supplied to our house. The voltage can increase more than 2000V in our normal 220V supply. The over voltage can severely damage the electric device running at the time. This sudden over voltage is known as spikes. Spikes are very brief over voltage up to 2000V or more caused due to lightening, power- line faults etc. To save the electronic device from these spikes, we need the special, equipment called spike guard. Spike guards are the electronic device, which remove the spike and prevent it from entering into the main system.

SOFTWARE AND DATA SECURITY

Data and programs or software is very important things. Computer can not perform any task without software. We cannot operate our computer without operating system software. Some information of organization may be very important and the loss of these data can cause serious damage to the organization. It is very costly to recover these important data and some cases that is impossible to recover them. So, data and software security is essential for any organizations as well as every computer users. Software security is the most convenient way of safeguarding our computer system.

The protection of data and programs used in computer system is known as software security.

For protection of data and programs in our computer systems, we should apply some security measures. Some common software security measures are as follows:

Ø Password Protection

Ø Backup System

Ø Defragmentation

Ø Scan Disc

Ø Virus Scanning

PASSWORD PROTECTION

The password scheme is one of the easiest and easiest and reliable method of protecting important data and information in our computer system. It is the common type of authorization control. If we protect our document by using password, only authorized users can open the document. Password is the primary source of data protection; it is a set of characters that acts like a key to unlock the system. Separate password can be used to access a system, an application, or even a file in a given application. The user in an organization who is permitted to access the company database is issued with a user ID and password and only certain level of access rights are provided to them by database administrator.

The success of this type of security depends on the ability of the user to create a password that is difficult to guess and to keep the password confidential. In order to ensure tight system security, many companies have policies that mandate the use of hard to guess passwords or randomly generated password and require employees to change their passwords frequently.

Some common rules while creating password:

· Password must be at least 6 characters.

· The word used in password should be difficult to guess for others.

· We should keep our password confidential.

· We have to change our password frequently.

· Files, which store password, must be encrypted.

BACKUP SYSTEM

Creating backup consists of making extra copies of programs or data. It provides safeguard against the loss of data or programs in computer memory, on hard disk or on diskettes. While creating backup data to a file, we have to give file name and location for the file to be saved. We can create a extra copy of data in our hand disk by using backup utility. Sometime our original data in the hard disk may erase, in that case we can restore our data from backup copy. It is always a good idea to create backup copies of our important data and programs.

DEFRAGMENTATION

Defragmentation is the process of rewriting parts of a file to contiguous sectors on a hard disk to increase the speed of access and retrieval. When files are updated, the computer tends to save these updates on the largest continuous space on the hard disk, which is often on a different sector than the other parts of a file. When the files are fragmented the computer must search the hard disk each time the file is opened to find all of the file parts, which slows down response time.

Thus hard disk needs to be defragmented using disk defragmenter. The defragmenter is available in most of the latest operating system such as windows 98, windows XP, windows vista in its system tool.

SCANDISK

Scandisk feature is used to detect and repair errors on disk. This feature is available in windows 95/98/Me and Dos.6.2 operating systems. The scandisk feature included in windows 95/98 can search corrupted files also.

VIRUS SCANNING

Computer viruses are the most defective factor of data and software. Viruses may damage our data and software. Viruses produce several unusual symptoms in our computer and used to give trouble to the user while working with computer. So, we should keep our computer free from viruses. For that we should scan our computer regularly using latest and updated Anti-Virus software. We can also install an ‘On access’ scanner and configure it to start automatically each time we boot our computer.

USING ORIGINAL SOFTWARE

We should not use pirated software but should go for the original software. The pirated software can contain several viruses. No one can guarantee the stability and performance of the pirated software.

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What is Multimedia Technology?

As we know multimedia system can create, store, compress, decompress and show the multimedia contents. Several techniques can be used by multimedia systems to do so. These techniques are collectively called the multimedia technology. Multimedia technology comprises of different techniques that are used by multimedia systems.

By the use of multimedia technology different multimedia applications have been built and implemented in real life to make different jobs easier. Educational multimedia applications enable students to study at home. Different animation packages help to visualize the different phenomenon, which would otherwise be impossible in classrooms. We can visualize several complicated processes like how human heart works, how is the structure of human heart, how brain transmits signals, how volcanoes erupts and lots of other things with the help of multimedia technology. Thus, multimedia technology has enabled us to visualize and realize virtually, many things that would not be possible otherwise. Even if it was possible, it would be very costly for general people to afford it. We can even do the lab exercise without science laboratory by the use of laboratory multimedia made by simulating the laboratories.

Multimedia technology has also improved the communication systems. We can use videoconferencing tools these days by which we can held the huge world wide conference without every body meeting in a same place. In video conferencing every body taking part in the conference sit aside of their computers and put their news, views and ideas in front of other participants. The participants also can comment, accept or reject ones ideas or put any questions ahead for discussions. Through video technology every participants of the conference can also see each other in their multimedia computers. Video conferencing is in fact a tool and a technology that virtually brings many people spread all over the world together to discuss on some matters. People could interact witheach other as if the single conference hall.

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MULTIMEDIA AND ITS APPLICATION

MULTIMEDIA

We often see different pictures, songs and movies in our computer. Sometimes we also hear that some actions in films are not performed real but are made by computer animations. We see TV advertisements, different attractive advertisements in newspapers, and many other designs in walls, pamphlets and other places. How these have been possible after all? All of these things are made by using multimedia tools. These days, multimedia computers are used as the most prominent multimedia tool to develop such graphics designs, animations, videos, image editing, etc. multimedia computers are nothing but simply the computers like we use in our home which are enhanced with many other multimedia hardware and software. Multimedia computers are capable of generating, storing and displaying multimedia contents. Now a question arises”What is Multimedia?” lets try to answer it.

As the name implies, multimedia is the integration of multiple forms of media. Multimedia is the technology that uses any combination of different media; it may or may not involve computers. It may include several media like text, spoken audio, music, images, animation, and video. For example, a presentation involving audio and video clips would be considered a “multimedia presentation”. Educational software that involves animations, sound and test is called “multimedia software”. Multimedia programs are often interactive and include games, sales presentations, encyclopedias, and many more. Any systems can be said interactive if users could act or command the system and the system works accordingly. For example: in media player a playing video pauses if the user clicks on the pause button and starts again when user clicks on the play button and starts when user clicks on any button. The user’s clicks here are considered as the user’s interaction and the response made by the system is called interactive response. Users can interact in many other ways instead of mouse. If any multimedia supports or response specifically on one or more of the user’s interaction, then such multimedia is called the interactive multimedia. Such interactive multimedia has gained lots of popularity these days.

Multimedia requires the large amount of data to be stored. Hence, CD-ROMs and pen drives are the good option for storage of computer multimedia files. We could store multimedia in other high capacity storage devices which are also faster and easy to use. But mostly we choose CD-ROM and pen drive as multimedia storage devices as it is very cheap, it can store lots of data and it is very easy to store and handle. Such CD-ROMs which contain multimedia files are called “Multimedia CD-ROMs”. Nowadays we can get different multimedia CDs in the market which contain the entertaining and educational materials.

MULTIMEDIA SYSTEM

System means the combination of different components which work in coordination with each other in a certain manner so as to serve some specific purpose. Multimedia is the technology which can disseminate two or more different media like text, audio, video, etc in a single time frame. Thus multimedia system means the proper combination of different multimedia components which work together to create, edit, store and disseminate the multimedia components. Almost all of today’s multimedia systems take advantage of power and ease of computer systems. Without computers, today’s sophisticated multimedia cannot be thought of. So, multimedia system could be more accurately defined as the combination of computer hardware and software designed so as to create, store and disseminate the multimedia content.

The multimedia computer generally contains the following components.

1) Computer

2) Multimedia Software

3) Sound card

4) CD-Drive

5) Micro-Phone

6) CD-ROM Disk

7) Multimedia speakers/Head-Phones

8) Digital Camera and many other components.

All of some of the above mentioned components work together to make up the multimedia system which can capture, digitize, compress, decompress, retrieve the multimedia component (multimedia data) and show it into the output devices like Computer Monitor, Multimedia Projectors, etc. Literally speaking, all the components that could be used in the multimedia system are impossible to list out. The above mentioned are only some of the important components of multimedia computer system.

ADVANTAGES OF MULTIMEDIA

We have already mentioned various advantages of using multimedia. We can still specifically list out following points that explains the advantages of the multimedia.

1. It can be used to help students and teacher to teach as well as learn the given topics easily.

2. It can be used to spread the knowledge easily all over the world wide in the cheap cost.

3. It is easy to take the multimedia files from one to other places as it can be stored in the cheap and light storage devices like CD-ROM.

4. It can be used for any subject and for anyone.

5. It can be used in Television, Films Industries and for personal entertainments.

6. It is highly used to realize the concept of Open University, Distance Education System, and Video Conferencing.

7. It is also used in Internet to make up the interactive web-page contents.

8. We can give the everlasting impression to the intended audiences on a specific topic by the use of multimedia.

9. Colored pictures, Motion pictures and other graphics could be shown in monitors and other big screens so that many people could view it and make out the impression about it.

10. Multimedia systems are generally very interactive so it is interesting to use.

DISADVANTAGES OF MULTIMEDIA

In comparison to the enormous advantages we have very little disadvantages of multimedia. These disadvantages could be listed out as:

1. It is expensive to produce multimedia contents.

2. It is expensive to set up the multimedia systems.

3. It needs well trained manpower to create and use it.

4. Multimedia files are too large so, it is time consuming to transfer across the Internet and Intranet.

MULTIMEDIA TECHNOLOGY

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Detailed System Design

Detailed System Design

As we already know the concept is a sketch of the structure and/or skeleton of the Information System, it guides the detailed design hence adding flesh to make it move towards becoming the system. As the scope and general configuration of the Information System have been established, the detailed design of the system may be started.

Sometimes it is impractical to explain each and every steps of doing procedure for detailed design for the following reasons.

1. There is a wide variety of approaches to system design in terms of organizing, conducting and defining it.
2. Systems design is a complex of concurrent activities where as the nature of description can proceed along only one line.

The first step in systems design is not a technical one. It is concerned with gaining support for the work that follows. Systems designers must have the support of most members of the organization to obtain information for the design of the system and to obtain acceptance of the final system.

Therefore, at least members of the organization should be informed of the objectives and nature of the study. It is preferable to draw many members into the study.

Aim of the detailed design

The detailed design of an Information System is closely related to the design of operating systems.

The aim of the detailed design is to furnish a description of a system that achieves the goal of the conceptual system design requirements.

This description consists of drawings, flowcharts, equipment and personnel specifications, procedures, support tasks, specification of information files, and organization and operating manuals required to run the system.

Conceptual design gives the overall performance specifications for the Information System; the detailed design yields the construction and operating specifications.




Document the detailed design

The end of the detailed design project is production of the documents that specify the system, its operation, and its design justification.

Documentation Consists of
1. A summary
2. Detailed flowchart
3. Operations activity sheets showing inputs, outputs and transfer functions.
4. Specification of the data base or master file.
5. Computer hardware requirements.
6. Software (programs)
7. Personnel requirements by type of skill or discipline.
8. Final (updated) performance specifications.
9. Cost of installation and implementation of the system.
10. Cost of operating the system per unit of time.
11. Program for modification or termination of the system.

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Implementation, Evaluation and Maintenance of Information System

Implementation, Evaluation and Maintenance of Information System

Implementation

The design of a management information system may seem to management to be an expensive project, the cost of getting the MIS on line satisfactorily may often be comparable to that of its design, and the implementation has been accomplished when the outputs of the MIS are continuously utilized by decision makers.

Once the design has been completed, there are four basic methods for implementing the MIS.
These ares-
1. Install the system in a new operation or organization.
2. Cut off the old system and install the new
This produces a time gap during which no system is in operation. Practically, installation requires one or two days for small companies or small systems.
3. Cut over by segments
This method is also referred as” phasing in” the new system. Small parts or subsystems are substituted for the old. In the case of upgrading old systems, this may be a very desirable method.
4. Operate in parallel and cut over.
The new system is installed and operated in parallel with the current system until it has been checked out, then only the current system is cut out. This method is expensive because of personal and related costs. Its big advantages are that the system is fairly well debugged when it becomes the essential information system.

Plan the implementation

The three main phases in implementation take place in series.
These are

1. The initial installation
2. The test of the system as a whole
3. The evaluation, maintenance and control of the system.

Many implementation activities should be undertaken in parallel to reduce implementation time. Training of personnel and preparation of software may be in parallel with each other and with other implementation activities.

The first step in the implementation procedure is to plan the implementation. Some analyst includes the planning of the implementation with the design of the system, the planning and the action to implement the plan should be bound closely together. Planning is the first step of management, not the last. The MIS design and the urgent need for the system at the time the design is completed will weigh heavily on the plan for implementation.

Implementation Tasks

The major implementation tasks consists of-

1. Planning the implementation activities
2. Acquiring and laying out facilities and offices
3. Organizing the personnel for implementation
4. Developing procedures for installation and testing
5. Developing the training program for operating personnel.
6. Completing the system’s software
7. Acquiring required hardware
8. Generating files
9. Designing forms
10. Testing the entire system
11. Completing cutover to the new system
12. Documenting the system
13. Evaluating the MIS
14. Providing system maintenance(debugging and improving)


1. Planning the implementation activities

Establish Relationships among tasks

For small projects, the order of performance may simply be described in text form. A Gantt chart or network diagram makes visualization of the plan and schedule much clearer.

For large projects, many concurrent and sequential activities are interrelated so that a network diagram must be employed in any good plan.
Establish a Schedule

Schedule is prepared by having the system designers estimate the times between the events in the program network. The critical path (longest time through the network) can be calculated. After specifying the starting date, the end date is established.

Cost Schedule to Tasks and Time

The cost for completing each task required to complete is established as part of the plan; then the rate of expenditures should be budgeted.

Reporting and control of the work in progress may be obtained by weekly meetings. The financial personnel must make certain that report formats allow them to show cost and technical progress relationship as well as cost and time.

2. Acquiring and laying out facilities and offices

For the installation of a new system to replace a current one may require a major revision of facilities as well as completely new office, computer room etc.

The MIS project manager must prepare rough layouts and estimates of particular floor areas that feel to be needed. The manager then prepares cost estimates.

Space planning must be done by the space to be occupied by people, the space occupied by equipment and the movement of people and equipment in the work progress. A large investment in good working conditions will repay its cost many times.

3. Organizing the personnel for implementation

As the implementation tasks have been defined, management usually assigns a project manager to guide the implementation.

The purpose of the MIS is to increase the amount and quality of their contributions, the system is their system.

Top management must make the middle managers for their involvement in implementation, besides these, systems specialists, computer programmer; top management should make sure that each people who will operate the system should have active parts in the implementation.

4. Developing procedures for installation and testing
After organizing the personnel for implementation the next task is to develop or prepare the procedures for implementation. As the project leader has the network plan for proceeding with the implementation, this leader calls the key people in the project to prepare more detailed procedures for system installation.

Procedures for evaluating and selecting hardware must be spelled out. Procedures for phasing in parts of the MIS or operating the MIS in parallel must be developed.

The major part of implementing the MIS is the testing of each segment of total system as it is installed.

5. Developing the training program for operating personnel

A program is developed keeping in mind to impress management and support. After developing the program, it is necessary to train operating personnel in their new duties. They must have a thorough understanding of what the new MIS is like and what it is supposed to do. They must learn how it will operate. They are faced with many changes in their work and have to obtain acceptance of changes.

As there are various levels of personnel and these people will be working with only a small part of the MIS, the seminars should be designed to provide them with an understanding of the complete system.

6. Completing the system’s software

As the software is developed internally or under contract, in both cases, the software development must take in mind the nature of the hardware required.
As the system designers and programmers provide the flow diagrams and the block diagrams during the detailed design state. Some modification may be required, as the implementation stage progresses.

7. Acquiring required hardware

This acquisition is usually the limiting factor in getting am MIS implementation. These tasks should be started during the design stage.

The decision is to be needed, whether to buy or lease the hardware. Capital expenditure analysis is only one of many factors involved in this decision. Others are prestige, usage etc.

8. Generating files

In the implementation stage, the actual data must be obtained and recorded for the initial testing and operation of the system. This requires format of the data, storage form and format and remarks to indicate when the data have been stored.

The collection of data used in routine operations is often called the master file.

Responsibility for file maintenance for each file item should also be assigned. The development of files or databases belongs to information system designers and storage and retrieval experts.

The translation of specifications for files into computer programs is a function of computer specialists.

9. Designing forms

For controlling the marketing, a salesperson has to fill out the forms summarizing the day’s activities. The form ensures the right information to be supplied for computer storage.

Forms are required not just for input and output but also for transmitting data at intermediate stages.

10. Testing the entire system

As the total system is installed, tests should be performed with the test specifications and procedure. A test during installation stage consists of component tests, subsystem tests and total system acceptance tests.

Components may be equipment (that can be new or old), new software programs, new data collection methods, work procedures, reporting formats. Difficulties that occur during component tests may lead t design changes.

As more components are installed, subsystems may be tested. There is a difference between the testing of component and the testing of a system.

System tests require verification of multiple inputs, complex logic systems, and timing aspects of many parts.

11. completing cutover to the new system

Cutover is a point at which the new component replaces the old component to the new system replaces the old system. This involves old forms, old files and old equipment being retried.
The debugging proves associated with the cutover to the new system may extend for several months.

12. Documenting the system

Documentation of the MIS means preparation of written descriptions of the scope, purpose, information flow components, and operating procedures of the system.

Documentation is a necessity for troubleshooting, for replacement of subsystems, for interfacing with other systems, for training new operating personnel and also for evaluating and upgrading the system.

13. Evaluating the system

After the MIS has been operating smoothly for a short period of time, an evaluation of each step in the design and of the final system performance should be made.

Evaluation should not be delayed beyond the time when the system’s analysts have completed most of the debugging. The longer the delay, the more difficult it will be for designer to remember important details.

The evaluation should be made by the customer as well as by the designers.

14. Providing system maintenance

Control and maintenance of the system are the responsibilities of the line managers.

Control of the systems means the operation of the system as it was designed to operate. Sometimes, well-intentioned people or operators may make unauthorized changes to improve the system, changes that are not approved or documented.

Maintenance is closely related to control. Maintenance is that ongoing activity that keeps the MIS at the highest levels of effectiveness and efficiency within cost constraints.

Maintenance is directed towards reducing errors due to design, reducing errors due to environmental changes and improving the system’s scope and services.

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Conceptual System Design

Conceptual System Design

During the system analysis, the analysis of system data is very important. Analysis of data is made up of more than one level at the beginning (first level) and different ideas are used at each level. At first level, analyst develops a conceptual system design.

Since the conceptual design sets the direction for the management information system (MIS). It is vital that managers participate seriously and heavily at this stage. Conceptual design is sometimes called feasibility design, gross design or high level design.

The conceptual design phase takes as input.
1. A crisp statement of a management information requirement and
2. a set of management objectives for the MIS

In the conceptual design stage that the alternative overall MIS designs are conceived and the best one is selected by the system analyst in consultation with the top management. The feasibility of meeting the management objectives for the MIS is assessed showing how the system will work at the high level is drawn. Therefore, conceptual design is also known as gross design; high level becomes the basis for the detailed MIS design.

Hence, conceptual design is a pre-design for the detailed design. In fact, conceptual design is the “centerpiece” of the process. Only after conceptual design is completed, it can be sure that the MIS can successfully be constructed.

The conceptual design involves the following tasks.

1. Defining problems in more details.
2. Refining the management objectives to set system objectives.
3. Establishing system constraints.
4. Determining information needs and their sources.
5. Developing alternative designs and selection one from these various designs.
6. Document the conceptual design and preparing the report.

1. Define the problem-

There is no doubt that problems exists in any dynamic business. The most important is that what are usually lacking are clear definitions of the problems and the priority system on the basis of problem is the main solution. Therefore, management must take the first step in MIS design by formulating problems to be solved. The problem can be solved by the iterative process.

The goal for the business leads to the objectives of the general business. From the objectives, plans are derived. Each business objectives and business plans are derived. Each business objectives and business plans are associated with information needs. These Information needs are the problems to be solved by the MIS function. The statements of needs are enough for designing process.
1. Stating the information need.
2. Asking questions about that need.
3. Suggesting interpretation of that need.
4. Detailing the original statement.
5. Reviewing the more detailed statement of need with management.
These steps are repeated until the information needs and the problem to be solved are really understood. The process of problem refinement flows naturally into the system objectives.



2. Set System Objectives

Most of the time it is quite difficult to state objectives for systems that covers all the functional areas.
The manager must define the system objectives in terms of the importance of information demands and not in terms of the satisfaction of demands that are not related to an objective. System analyst tends to stress processing efficiency and staff and functional supervisors commonly believe that their objective is “to complete the required report in time for management use”. This view disregards the real objectives of the system design, management’s effectiveness.

The value of system lies in the benefits of the users. When we ask for the objectives, a college principal may reply,” provide quality education” and a government bureaucrat may say” provide more jobs for the unemployed”. Despite its difficulty being specific is necessary. System objectives should be expressed in terms of what managers can do after their information requirements have been met.
In summary, the first steps in systems design attempts to answer the question” what is the purpose of the system?” why it is needed? What is it expected to do? Who are the users what are their objectives?

3. Establish System Constraints

The iterative nature of the systems design process is easily understood when we consider the third step in the process-establishing constraints. It can also be called as problem boundaries or restrictions, constraints enable the designer to stipulate the conditions under which objectives may be attained and to consider the limitations that restricts the design. The two steps of setting objectives and establishing constraints may be considered together as one.
Constraints may be viewed as a negative limitation on systems design, there is a positive benefit also. Establishing constraints will help to ensure that the design is realistic.
Constraints may be classified as external or internal to the organization.

External Constraints
The external environment of the organization is concerned by the customer. Order entry, billing and other systems that interface with the customer’s needs in mind. If some outputs from the system are not acceptable to the customer, a definite limitation must be faced up.
The government imposes certain restrictions on the processing of data. That may be the need to maintain the security of certain classes of information to comply with law and regulation in the conduct of business (e.g. taxes, reporting).
Unions can also affect the operations of systems involving members in working conditions.
Suppliers are also an important group to be considered when designing information systems because these systems frequently interface with that group.

Internal Constraints
If top management support is not obtained for the systems concept and for the notion that computer based information systems are vital for management planning and control, the type of design effort cannot be implemented. A good environment for information systems must be set, and one essential requirement is the approval and support of the top management.

Organizational and policy considerations frequently set limit on objectives and modify an intended approach to design of the system. Company policies frequently define or limit the approach to systems designs.

Personnel needs and personnel availability are a major limiting factor in both the design and utilization of information systems. Computer and systems skills are among the most critical in the nation. The most significant constraint of all is the one concerning the people.

Cost is a major resource limitation. The cost to archive the objectives should be compared with the benefits to be derived.

Self-imposed restrictions are these placed on the design by the manager or the designer. The manager will also restrict the amount of time and effort devoted to investigation. To achieve the objective, the manager may have to scale down several requirements to make the system fit with other outputs, equipments or constraints.

4. Determining Information needs and sources

For a good system design, a clear statement of information needs is very important and necessary. Many organizations spend huge amounts on hardware and software to maintain existing systems or build sophisticated data banks, without first determining the real information needs of management: the information that can increase the ability of managers in critical areas such as problems, alternatives, opportunities and plans.
The optimum results cannot be achieved unless managers can provide the specifications for what they want out of an information system. The manager needs information for variety of reasons concerned with the management process. The type of needs at various times and various purposes depends largely upon two factors.
a) The personal managerial attributes of the individual manager and
b) The organizational environment in which decisions are made.
The information sources are important for determining information needs. The system may require external information or the internal.

5. Alternative conceptual designs and selecting one

The development of a concept of a system is a creative process that involves synthesizing knowledge into some particular pattern. The concept of an MIS would consist of the major decision points, patterns of information flow, channels of information and roles of managers and competitors. The concept is the sketch of the structures or skeleton of the Information System, which guides and restricts the form of the detailed design. If conceptual design is the skeleton, then detailed design is the flesh.

E.g. two teams of students are trying to do project on the tourist guide and contact information system. One concept produced is a sketch showing a detail about the particular places describing its culture, heritages along with the colleges. Hotels and trade. Where as another team produces a sketch of description of colleges along with the description of faculty and the fee structures on various needs.

It is obvious that each alternative concept of a system has advantages and disadvantages. Sometimes one concept will dominate all others by major criteria.

6. Document the best design

Sufficient information has been accumulated to begin a more detailed description of the system concept. This description includes essentially a flowchart or other documentation of the flow of information through the system, the inputs and the outputs.

The manager should be involved to the extent that the system provides the information required, the designer is concerned with the nature of the materials and equipment as well as with technical processing considerations.

Details to be worked out later by the designer will include exact instructions as what data are to be captured and when, the files are to be used, the details of how processing is to be done, what outputs will be generated by the system etc.

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Definition, Bus, Ring, Star Topology

The computers on LAN can be physically connected with the wires in different manner as the requirement of an organization or office. The manner in which the computers on the LAN are connected is known as LAN Topology. So, network topology is the physical layout of cabling for connecting computers on the network. It can be defined as the arrangement or connection pattern of computers on a LAN. A LAN topology describes how the computers are physically connected and how do they communicate on the network. It determines the data paths that may be used between any pair of nodes of the network. There are three basic network topologies. They are Bus topology, Ring topology and Star topology.

BUS TOPOLOGY

In a bus topology computers are arranged in the linear format. So, it is called Linear Topology. In this topology, all nodes are connected directly to the common cable with the help of T-connectors. The common cable is also known as also known as a network bus or trunk. The network bus acts as a backbone to the network.Many different lengths of co-axial cables are used in this type of topology. On the both side of the network bus (i.e. coaxial cable), BNC (Bayonet Naur Connector) jacks are connected. A T-connector is used to join segments of cables and computers. The BNC jack on each side of network bus is connected to the T-connector i.e. top the T-connector is connected to the NIC card of a Computer. The T-connectors connected to the last computers on both sides are attached with terminators.

In this network topology, the position of the server is not fixed i.e. can be any where on the network. When any node sends the data, the data passes on both directions in the form of packets through the bus and reaches to all the nodes. Since each data packet contains the data bits and the destination address, only the destination node accepts the data packets. The terminators at both end sides absorb the packets or signals travelling on the bus to prevent the bouncing of the signals which causes interference.

ADVANTAGES

a. Since each small segments of cables are joined to form a trunk or network bus it is easy to setup computers on the bus.

b. Since nodes are arranged in the linear form, it requires the less amounts of cables.

c. The coaxial cables used for networking are inexpensive and joining connectors on the cables is also easy.

d. Failure of any node does not affect other nodes on the topology.

e. Well suited for temporary networks (quick set

up).

DISADVANTAGES

a. If the backbone cable i.e. network bus has problem then the entire network fails.

b. Finding fault on this topology is not easy.

c. It provides limited flexibility for change, so adding or removing nodes in between is not easy.

d. The performance degrades when the

number of computers is more on the. so, it is not suitable for big size network.

RING TOPOLOGY

In a ring topology, all nodes are arranged in the shape of a circle (ring). Both ends of a cable are connected to the nodes so there is no any point like a bus topology. Since the both ends are connected to the nodes there is no any terminator in this topology. In this topology, many different lengths of co-axial cables are used according to distance of computers. In this topology each computer acts like a repeater that boosts an incoming signal before passing it on to the next computer.

In this topology, data or messages are transmitted in one direction either clockwise or anticlockwise. When any node sends a message or data, the message or data reaches to the first node on the circle. If the first node in the circle is the destination node then it absorbs the data or message otherwise it regenerates the signal and passes to another node on the loop and so on. If the message or data is not absorbed by any node then it is absorbed by the sender node.

ADVANTAGES

a. Since each node on the ring acts as a repeater, no any external repeater is required to boost up the signals.

b. It supports high data transmission. Rate.

c. It is easy to setup.

DISADVANTAGES

a. If any node or connecting cable fails the entire network does not work.

b. The diagnosis of the fault is difficult.

c. Since data or message reaches on the node in sequence, so addition of few nodes increases the communication delays.

d. It provides limited flexibility for change,

so adding or removing nodes in between is not easy.

STAR TOPOLOGY

Star Topology is the most popular topology used to connect computers and other network devices on the network. In a star topology all nodes are connected through a centrally located device in the form of star. But the shape of arrangement of computers is not necessarily to be star. The device whic

h connects computers on the network is either a hub or a switch. A hub or a switch has connecting ports or slots where the wires running from each node are connected. A twisted pair cable (specially unshielded twisted pair cable) is used for connecting a computer and a hub or switch. Each segment of UTP cable is attached with RJ-45 jacks. And one side of the UTP cable is connected to the node and another side is connected to the hub or switch. When any node sends data or message, the data or message reaches to the hub or switch and then to the targeted computer on the network.

ADVANTAGES

a. Computers can be added or removed easily without affecting the network.

b. If any of the workstation or the connecting cable fails, it does not affect the remaining portion of the network.

c. Fault detection in the star topology is easy.

d. It is easy to extend so it is suitable for a large network.

e. It is one of the reliable network topology.

DISADVANTAGES

a. Since each node is required to connect with the centralized hub or switch more cables are needed which increases the cost of installation.

b. The entire network fails if there is any problem on the hub or switch.

c. In comparison to Linear and Ring topologies, it is little expensive as it requires more length of cables and other controlling devices.

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