Information Systems to Different Levels of Management

Transaction Processing System (TPS):

Business transactions are events that serve the mission of the business. They are the primary means by which the business interacts with its supplier, customer, partners, employees and government. Transactions are significant to us because they capture and or create data about and for the business. Examples of transaction include purchases, orders, sales reservation, shipment invoices and payments.

 "TPS are information systems application that capture and process data about (or for) business transactions they are sometimes called data processing systems."

The analysis and design of transaction of transaction processing systems tends to focus on factors such as response time, through put (volume of transaction), accuracy and consistency.

Management Information Systems:

Management information systems supplement TPS with management reports required to plan, monitor and control business operation. A MIS is a information system application that provides for management oriented reporting usually like current sales & marketing, recruitment and so on MIS produce information based on accepted management or mathematical/statistical models

Expert System:

An expert system is an information system application that captures the knowiedge and expertise of a problem soiver or decision maker and then simulates the thinking of thaiexpert for those who have less expertise. Expert sysiems imitate the logic and reisoning of the experts within their respective fields. For example

A food manufacturer uses an expert system to preserve the production expertise of experienced engineers who are nearing retirement Expert systems are implemented with artificial intelligence technology often called expert system shells that captures and simulates the reasoning of the expert

Decision Support System:

A decision support system (DSS) is an information system application that provides its users with decision oriented information whenever decision making situation arises. When applied executive managers, these systems are sometimes called executive information system. A DSS does not make decision or solve problems. People do. Decision support systems are concerned with providing useful information to support the decision making process. In particular. decision support systems are usually designed to support unstructured decisions. Those decision making situation that cannot be predicted in advance. DSS is based on the reality that the information needed to support unstructured decisions already been captured by transaction processing and management information system. The DSS provides the decision maker with tools (data mining tools) to access that information and analyze it to make a decision. In general a DSS provides one or more oi the following types of support to the decision maker:

• identification of problems or decision making opportunities.
• identification of possible solutions or decisions
• Access to information needed to solve a problem or make a decision
• Tc perform what if analysis
• simulation of possible solution and their likely results

Levels of Management

Differences can be identified between these kinds of information at the various levels of the organization.

At top management level of the organization, information tends to be ill structured, ad-hoc, informal, external, uncertain, and concerned with the future.

At middle management level information is more structured, formal, internal, regular,certain and concerned with the near future.

At operational management level information is repetitive, programmable, and largely internal and has a very short time- horizon.

The purposes of information therefore changes according to the level at which it is aimed. paradoxically, the higher up organization a manager is the less he will rely on formal information, and yet still needs to be informed (at summary level) of all the organization's activities.

On the other hand, the lower the manager is in the hierarchy, the more he needs to rely on precise and up to date information for his activities; yet he only needs a very limited set of the total information for his own particular activity.

Operational Management:

Requires day to day personnel performance information, machine performance and information on material usage.

At the middle management level:

This can be combined and summarized into exception reports personnel equipment or materials above or below accepted levels and comparisons against budget.

At top management level:

Middle management information can be combined and summarized, and also perhaps at the stage projections or forecasts produced.

Types of Functional Managers

• Finance manager (Chief financial officer)
• Production manager
• Marketing manager
• Human resources manager IT Manager (Chief information officer)

Board of Directors

These are a set of individuals who are appointed by shareholders to run the business organization on their behalf. The board of directors will usually consist of executive (working) and non-executive (non-working) directors. Their functions include formulation of long term strategies, decision making, appraisal of senior managers and other similar tasks"

Managing Director (Chief Executive)

This !s the individual who is responsible for the overall operations of the business. Usually occupying a seat on the board he/she is responsible for overlooking all functional areas while at the same time communicating operational performance to the board.

Production Manager

This is the individual who is responsible for planning production runs, appraising factory staff, measuring production performance, instructing purchasing managers, improving machinery and technology, etc. His/her function requires a detail understanding of technical systems and that which is associated with the real work environment.

Finance Manager

This is the individual who is responsible for raising suitable debt and equity finance, allocating financing to other operations, investing surplus funds appropriately, overlooking the preparation of financial statements, budget preparation, etc. His/her function requires a detail understanding of financial management and probably accounting skills as well.

Marketing Manager

This is the individual who is responsible for planning promotions, advertising campaigns, making pricing and distribution decisions, brand management, labeling, etc. He/she should be a good communicator, have a broad understanding of customer views and also be able to manage their requirements effectively.

Human Resources Manager

This is the individual who is responsible for identifying labor requirement, selection, recruitment, appraisal and training of the general employees of an organization. He/she should be a good communicator, have a broad understanding of employee views and be able to negotiate and motivate most employees.

IT Manager (Chief Information Officer)

This is the individual who is responsible for managing all IS related activities within an organization. His/her functions includes;

• Formulating long term IS strategies.
• Appraising IS systems.
• Selecting, recruiting and training IS staff.
• Servicing the information requirement of all aspects of the organization (most important)
• Ensuring timely upgrade of hardware and software systems.
• Training general staff in using IS facilities.
• Overlooking organizational computer and communication systems.
• Making recommendations on IS related activities to the board of directors

Management and Organization

Although management is recognized as a vital activity in virtually all organizations, it is in fact very difficult to obtain agreement about the precise definition of what management is. At the most basic level, it is sometimes referred to as the art of getting things done through other people. This emphasis the fact, that managers achieve results by getting others to perform certain tasks.

Definition:

"Management is the process of designing and maintaining an environment in which individuals, working together in groups, efficiently act selected aims"

Also;

• Management applies to any kind of organization
• Management can take place at variety of organizational levels.
• The aim of all managers is the same: to create surplus
• Managing is concerned with productivity

Functions of Management

A manager performs 5 functions in an organization. They are;

• Planning
• Controlling
• Organizing
• Coordinating
• Commanding

Planning: All managers constantly plan for the future planning will generally include the following steps or stages.

• Setting objectives
• Developing alternatives to achieve objectives
• Evaluating the alternatives
• Selecting the best alternative
• lmplementing
• Review of success

Controlling: The function of monitoring the actual event and if there are any changes from the plans, taking action to correct them.

Organizing: Dividing the work among different individuals providing the relevant resources and seeing to that the different individuals are working towards the designated tasks.

Coordinating: There may be a large number of organizations performing variety of activities if the organization is to be successful, they have to work together and there should be coordination.

Commanding: According to Fayol (Fayol is an author) a manager issues commands which are followed by others. This term commanding through suitable in Fayol's times may not be applicable to the modern work force. A modern manager should be regarded as playing the following roles instead of commanding.

• Leading Communicating
• Motivating ' Decision Making

Information Systems Related Roles and Positions

IT Director/Chief information officer (CIO)
As a member of the board of directors, the IT director is responsible for all IS/IT activities within an organization. The role of the CIC is almost identical to that of the lT director. However he/she is also responsible for servicing the information requirement of the board of directors as well as controlling information flows and ensuring that adequate information is available across the organization.

IT Manager
The individual who is responsible for all aspects of information technology and related services within an organization. His/her functions include; formulation of long term IS strategies, appraisal of systems, communicating with the board, ensuring timely update of organizational computer systems, IT staff recruitment, etc.

Database Administrator (DBA)
The individual responsible for managing an organizations database systems. His/her functions include; setting up database systems, monitoring database operations, periodic backup taking, database maintenance activities, maintenance of the data dictionary, etc.

Systems Analyst
Is responsible for studying the existing system within an organization by means such as observation, interviews, etc. He / she is also responsible for documenting and making recommendations to systems designers.

Systems Designer
Is the individual who obtains the analysis report from the systems analyst and then uses this recommendation to construct a design for a new system. The functions performed by the systems designer include : Design of information flows, process planning, design of file structures, screen design, etc.

Application Programmer
Is the individual who is responsible for converting paper designs of the new system into a set of working applications. His/her role is often termed as the individual who is responsible for converting ideas into reality in a software systems context. The tasks performed include coding, screen design and testing.

Web Designer
A relatively new role to emerge in the IT industry. a web designer is usually referred to in context of small firms. He 1 she is usually responsible for or involved in analyzing, designing, developing and implementing a web based solution such as a web site for a client. Creativity and skill are of the essence for such individuals.

Maintenance Staff
These are the individuals who are responsible,for carrying out hardware and software maintenance activities with respect to information systems within an organization. Their main tasks include : upgrading hardware devices, upgrading software applications, troubleshooting, repairing damaged machines, dealing with viruses and other similar security breaches.

Data Entry Operator
Traditionally a data entry operator was considered to be an individual who read through hard copies of data and then keyed in (typed) the data as input to computers for later processing. The role at present is taken to be one, which is involved with performing repetitive tasks such as the work done by cashiers at supermarket terminals.

Organization Structure

All organizations have some form of structure which should facilitate the implementation of strategy and the achievements of objectives. In simple terms an organization structure can be defines as an established pattern of relationships among -the individuals, groups and departments within it. Although this pattern can be changed from time to time, the structure of the organization is relatively static framework within which process such as communication, leadership and decision making takes place. organization structure is concerned within which the way work is divided up and allocated, and how coordinated to achieve objectives is described as an organization's basic structure and in some organizations it will be illustrated in the form of a chart.

Types of Organizational Structures

Entrepreneurial Structure

A small organization is likely to have little in the way of formal structure, because the owners or managers can deal with most things on a personal face to face basis. It might be said to have an entrepreneurial structure, whereby everything revolves around one or a few central decision makers.

Functional Structure

The most common form of structure adopted when an organization has outgrown the entrepreneurial one is the functional structure. This divides the organization up into its main activities or functions (production, Sales, accounting and so on) and places manager in charge of each function under the overall control of the owner or a senior manager' This form of organization has a number of potential advantages, including: efficient use of specialized resources; and a career structure that enables people to advance within their functional specialism.

Divisional Structure

Example: Product base division:
This is a name, a sign or a symbol which helps to identify a product from other similar products. A manager is appointed in charge of a product or a brand and he & his subordinates are responsible for their products and brand performance.

Advantages:

• Better communication and co-ordination.
• Clear responsibility for the performance of products and markets.
• Specialization can be developed. (A sales person who is handling a particular type of hardware can develop knowledge in technical side and deliver a better service)

Disadvantages:

• There may be too many managers increasing the organization cost.
• There may not be a proper coordinated approach with regard to targeting customers. The same customer may be approached by different sales people of the company.

Geographical Based Structure

A manager is appointed for each region and he/his subordinates are responsible for all the organizations activities in that region.

Advantages:

• Large organization needs such a structure to operate in many areas successfully
• TransPort cost are minimized
• Better controi over pedormance
• Very fast & good decision making
• Regional taste and preferences can be effectively carried

Disadvantage:
Cost will be high due to high degree of duplication of activities (Example: more sales reps, accounts executives, show rooms, etc.)

Matrix Structure

Matrix structure seeks to add flexibility and co.ordination to traditional vertical hierarchy. One way of doing this is to create project teams made up of members drawn from a variety of different functions or divisions: each individual then has a dual role, as he/she maintains functional/divisional responsibilities. As well as memberships of the project. The matrix structure is sometimes appropriate for large multi- product companies which have significant interrelationships between their various operating units. If implemented this form of structure can:

• Help to improve decision making by bringing a wide range of expertise to problems
• Improve lateral communrcation and co-operation between specialists
• Most suitabie for IT Projects

Classification of Organizations - (Flow of Information) Lecture 03

Flow of information within an organization can be divided in to two groups.

1. Vertical flow (top-down or bottom up)
2. Horizontal flow

Vertical flow

This is where two or more individuals at different levels of the corporate hierarchy communicate with one another. At such a point one would automatically become the superior while the other becomes the subordinate.

Example:

A line manager reports to the production manager.

Horizontal flow

This is where two or more individuals at the same level of the corporate hierarchy communicate with one another. At such a point neither there is a superior nor subordinate.

Example: 

A marketing manager discusses a marketing plan with the production manager.

Classification of Organizations - (Stakeholder Groups) Lecture 02

Stakeholder
A stakeholder is someone who could affect or tends to be influenced by the activities of a business organization. A stakeholder could be an individual, an organization, a group of people or any other such entity.

Internal Stakeholders

• Shareholders, Investors (such as banks & financial institutions)
• Managers
• Employees
• Contract staff

External Stakeholders

• Suppliers
• Creditors (people who we owe money to)
• Customers
• The government and local authorities general community / Cause / Pressure groups

Shareholders

These are the people who have invested in the equity (seed) capital of the business. They are considered to be the owners of the business entity and hence take a great risk on their investment. It is natural that they also expect high returns. Their expectations include : capital gains and returns on investment in the form of dividends.

Their expectations include:

• Capital gains on sale of shares
• Adequate returns on investment in the form of dividends
• Security of their investment (confidence that their investment is safe)
• The right to participate in annual general meetings
• Their comments to be heard and considered by the BOD

Financial Institutions

These are organizations such as banks and debt providers who have provided loans to the firm.

Their expectations include:

• Timely payment of interest and capital repayment
• Security for their investment

Managers

These are the top most individuals in a firm. Comprising of the BOD, the MD and the senior managers they would tend to be one group which would be greatly affected by the affairs of a business. Similarly they are capable of exerting a significant influence on all business activates.

Their expectations include :

• An industrially competitive remuneration package
• Promotional prospects
• Job security
• Adequate training and personality development
• A suitable and stress free work environment
• Adequate authority to perform their job functions

Employees

These are the ordinary workers, office staff and other full time employees of the organization. The group as a whole is considered as the workforce of an organization and they tend to exept their influence through trade unions and other employee groups.

Their expectations include:

• Reasonable wages
• Promotional prospects
• Job security
• Safe and secure work environment
• Adequate training
• Jobs free from discrimination

Contract Staff

This group of individuals are similar to employees, however they have limited ability to influence business decisions as they work on a contract basis. Contracts usually require renewal and could be cancelled at short notice. They are likely to have lesser statutory entitlements than employees. However recent regulations in the EU devotes greater attention to the needs of such staff .

Suppliers

These are the providers of. raw materials and other support good and services to an organization.

Their expectations include:

• Adequate orders
• Timely settlement of debts
• Steady rise in orders
• Reasonable requests that could be compiled with
• Reasonable prices for their products and services

Creditors

These are individuals and organizations who are owed money by the organization.

Their expectations include:

• Timely settlement of debts.
• Adequate interest if delayed.

Customers

These are the individuals or organizations who purchase the products of the business.

Their expectations include:

• Quality products
• Reasonable prices
• Good after sales service
• Availability and range to choose from

Government and Local Authorities

The government takes an interest in business organizations due to several reasons.

These include:

• Taxation (a source of revenue for the government)
• When planning subsidies and assistance schemes
• Checking compliance with legal and state policies
• Assessing corporate ethical behavior

General Community

The general community would be concerned with the impact a business organization has on it's surrounding environment. For instance they maybe concerned about pollution, noise, disturbance, etc while at the same time show positive responses towards the creation of job opportunities and assistance to regional entities such as schools.

Cause / Pressure Groups

Focus on a particular issue and attempt to influence business activities in this respect.

Examples: 

• Animalwelfare
• Employment
• Anti smoking pressure groups

Classification of Organizations - Lecture 01

For most of our lives we are members of one organization or another - college sports team, a musical group, religious organization, a branch of armed forces or a business. Some organizations, like the army and large corporations, are structured very formally. Others, like a neighborhood basketball team, are more casually structured. But all organization, formal or informal are put together and kept together by a group of people who see that there are benefits available from working together towards some goal. So a basic element of any organization is a goal or purpose (the purpose that an organization strives to achieve; or organization often have more than one goal; goals are fundamental elements of an organization)

Objectives of Organizations

• Provision of a service
• Profit maximization
• Growth (expansion of market share)
• Support other organizations
• At times of hardship - Survival

Classifications of organizations

1. By ownership
2. By scale
3. By objectives
4. By sector
5. Other classifications

Organizations - Classified by Ownership

• Sole trader (1 owner)
• Partnership (2-20 partners)
• Limited liability company
• Private limited company (Pvt)
• Public limited company (PlC)

Sole Trader
A sole trader business is a private business which is set up and managed by a single individual. He/she makes the entire investment, enjoys the benefit of all returns and takes all risks relating to the business activities'

Example: Mark starts a hardware shop by his own

Partnership
A partnership business is one which is set up and operated by 2-20 partners. Usually coming from different specializations, they pool their strengths towards the development of the combined entity. The advantage of attracting a relatively larger amount of capital exists however it too is constrained by the unlimited liability of owners.

Example: Fred and David starts a software development company

Limited Liability Company
This is where several individuals invest and create a separate legal entity which functions without the assistance of it's owners. A board of directors is appointed by the shareholders to carry out the business activities on their behalf. The main benefits being that it's easy to raise a larger amount of capital as well as the benefit of limited liability.

Example: McFloyed Technologies (Pvt) Ltd

Organizations - Classified by Scale

• Multinational Companies (MNCs)
• Holding Companies

Multinational Companies
A multinational company is considered to be a large scale company which operates in both a local country and several foreign countries with at least a single production plant being in operation in a foreign country.

Holding companies
These are companies that usually avoid conducting ordinary business activities. Instead they hold on to controlling interest of other companies (both private and/or public) and investments. They obtain returns from these investments which they in turn distribute among their own shareholders.

Organizations Classified by Objectives

• Provision of a service (Government Sector)
• Profit maximization
• Expansion of market share
• Survival

Provision of a Service
Most government sector organizations (till recent times) placed more emphasis on providing required services for the benefit of the general public with less emphasis being placed on making profits. Sports clubs are yet another form of organization which focus on the provision of a service.

Profit Maximization
Most private sector companies attempt to maximize sales revenue while at the same time reducing costs and focusing on more effective and efficient operations. Thus generating greater profits which may either be re-utilized or returned to investors in the form of dividends.

Example: Most private sector organizations.

Expansion of Market Share (Growth)
Certain private and public sector companies maybe willing to forego current excess returns and instead reinvest these in improvement measures in order to gain more market share and thus potential increased returns in future.

Survival
This becomes the main objective of most firms at times of hardship such as recession, downturn of individual business, etc. They realize that they would not be able to make profits but instead focus on covering operational costs in an attempt to survive (avoid closure) until market conditions improve.

Organizations Classified by Sector

• Public sector (managed by the government)
• Private sector (owned and managed by individuals and other private companies)

Public Sector
The public sector refers to organizations that are owned by the state and run by the government or appointed management teams. The main objective of such organizations is to provide a service which is either desired or needed by the general community.

Private Sector
The private sector refers to business organizations that are owned and managed by either individuals or other private sector organizations. Their main objective is usually to maximize shareholder wealth and thus provide high returns to it's investors.

File Organization

A file organization essentially means organization of records in the file. Efficiency and utility of the file organization over another very much depends on the intended use of the file. Some of the basic file organization techniques are:

Serial File

In serial file records are collected in the order they arrive. When a new record is to be inserted, it is placed in the last block if there is a space. lf the last block cannot accommodate the record, a new block is allocated and the record to be inserted is placed. Deletion is performed by setting a flag called the deletion bit in the deleted record. Reusing the space of deleted records by storing new records which are to be inserted, is difficult. However, "garbage collection" routines can be used to keep track of the deleted records and the reusable space.

Since the record in a serial file are collected as they arrive without any prior analysis, categorization or normalization, searching a specific records from a serial file would often lead to an exhaustive search of the entire file.

Thus the time required to locate a record in a serial is very high if the file is speared over more than a few blocks. However, insertion of a new record into a serial is less time consuming. The address of the end of the file is known and the data is simply stored at the end and the end of file marker is appropriately shifted. Since updating a record in the serial file requires locating the desired record first, updating cost is also quite high for such file. In fact, the high retrieval cost of serial files is responsible for the restricted use of such files. The serial file organization is generally used for small files or when the data is collected prior to processing and where the data is difficult to organize.

Sequential File

In a sequential file records are placed sequentially onto the storage media. In addition, the records in the file are usually ordered according to the values of key attributes' The key is used to identify record uniquely. In a sequential search, since the records are examined according to the key sequence, in the worst case one may have to access all the n blocks of the file. i-n sequential file the successor record is immediately available and may even be present at the same block.

The insertion of a record in a sequential file is a complicated process. Normally the sequence would not be maintained if the new record rs inserted at the end. For small files, records beyond the point of insertion can be moved further to accommodate the new record. The insertion are usually done in batches where all the insertion request are stored in a separate file and at later time a batch update is executed.

Deletion of records can be performed by setting the deletion flag in the record to be deleted. When several records have been deleted, the file is reorganized to eliminate the gaps created in the file due to deletion.

Finally the updating of records in a sequential file may involve all the complications of insertion. Note that, The sequential file would not allow the insertion of records larger than the original record stored. If the key value is not changed and the updated record length does not exceed the original record length, the record may be rewritten to the original file. When the key value is changed or the record length increases, the update is similar to the insertion of a new record

Sequential files are frequently used in batch oriented commercial processing where insertion, deletion or updation are generally carried out in a batched mode, In this environment, get next type of command ii frequently used to retrieve or process successive records. For instance, the accounts department of a company while preparing salary statements would normally process the pay slips of all the employees of a particular department in a sequence. Hence if the employee records are stored with the Dept-no as the primary key, then specifying the Dept-no, the first employee record in the department is retrieved. The remaining employee records in the same department can now be readily accessed without much effort, using repeated get-next types of commands'

In spite of its simplicity and the advantages mentioned above, sequential files are not suitable in an environment where data has to be retrieved or updated in a more or less random order

Indexed Sequential File

The index sequential method of file organization attempts to reduce the access problem inherent in the sequential flies, without losing the benefits cf a sequential file organization.

This type of organization enables the user to process records either in a serial or in a random manner. The indexed sequential file, as the name suggests, is provided with indexes associated with the file. The indexes can be used to quickly locate any given record for random processing. Another important feature associated with an index sequential file is the use of an overflow area to handle insertion to the file. Unlike sequential file it is no longer required to rewrite the entire file when the records are inserted or updated. Indexed sequential file has three major components, namely

• Prime area (sequential file)
• Overflow area
• Index

The Prime Area
The prime area can be defined-as an area in which the records are written, when an indexed sequential file is originally created. The records in the prime area follow a strict key sequence. Hence the prime area is essentially a sequential file. In order to insert a record into the file a free area called an overflow area is associated with each file. It is to be noted that at the time an indexed sequential file is created, no records are placed in the overflow area

The Overflow Area
It has already mentioned that the overflow area(s) s essentially used to store new records which cannot be otherwise be inserted in the prime area without rewriting the sequential file. There are two types of overflow areas called the cylinder overflow area and the independent overflow area. In Cylinder overflow area the spare space in every cylinder is reserved for accommodating the overflow records. Thus overflow area is on the same cylinder as the prime area. This procedure has the advantage that locating an overflow record may require rotational delay but not a seek time. In an independent overflow area the overflow records from any where in the prime area maybe placed. The size and address of the independent overflow area maybe specified by the programmer. In this case maybe additional seek time may be required.

Hashed File

Hashing is a technique for providing fast direct access to a specific stored record on the basis of a given value for some field. The field in question is usually but not necessarily the primary key. In outline the techniques work as follows.

• Each stored record is placed in the database at a location whose address (RID or page number) is computed as some function (the hash function) of some field of that record. The computed address is called the hash address.
  
• To store record initial the DBMS computes the hash address for the new record and instructs the file manager to place the record at that position.
  
• To retrieve the record subsequently give the hash field value, the DBMS performs the same computation as before and instructs the file manager to fetch the record at the computed position.
  
• When two or more keys of a file are mapped into the same address by the hash function the event is referred as collision.

Hashed files must have a mechanism for handling collision. A collision occurs when two logical values are mapped into same physical key value. Suppose we have a logical key value 2034; we find that feeding this key value through the hash function that computes the relative block address 12. A little later we try to insert a record with the key value 5678. We find that this also translates to relative block address 12. There is no problem if there is space in the block for the record. As the size of the file grows blocks are likely to f ill up.

If the file manager cannot insert a record into the computed block then a collision is said to have occurred. One of the simplest schemes for handling collision is to declare an overflow area into which collided are placed. As the hashed file grows, however the number of record placed in the overflow are increases. This can cause degradation in the access performance. Various type of hashed files are now also available which dynamically resize themselves in responsible to update activity.

Physical Database Design

The physical or internal level organization of a database system is concerned with the efficient storage of information in the secondary storage devices. At this level we are no longer concerned with the application programmers views of the database. The physical to conceptual level mapping must provide the necessary shield to the user. The basic problem in physical database representation is to select a suitable file system to store the desired information. The file consists of records and records may consist of several fields.

The typical operations that may be performed on the information stored in the file are as follows.

• Retrieve: To find a record (or sets of records) having a particular value in a particular field or the field value satisfies a particular condition.
• Insert: Inserts a record or sets of record at some specific locations.
• Update: Modifies the field values of a record (or sets of records)
• Delete: Deletes a particular record or sets of records

The efficiency of a file system depends on how efficiently these operations can be performed on the file. However, the efficiency of these operations on a particular file may depend on the type of queries the file system needs to process. For instance a sequential file system turns out to be quiet efficient for an application where most of the storage and retrieval of record are performed sequentially. The same file system turns out to be inefficient in an environment where records are to be retrieved or updated randomly.