Chapter-3 Computer Software

Introduction to Software A Computer cannot do anything on its own. It must be instructed to do a job desired by us. Hence it is necessary to specify a sequence of instructions a computer must perform to solve a problem. Such a sequence of instructions written in a language understood by a computer is called a Computer Program. The term Software refers to a set of Computer Programs, Procedures & flowcharts describing the programs & how they are to be used. A Software package is a group of programs that solve a specific problem or perform a specific type of job.

For eg- A Word Processing Packages may contains programs for text editing ,text formatting , drawing graphics, spelling checking etc. Hence , a multipurpose computer system, like a personal computer in your home , has several software packages , one for each for every type of job it can perform. Software consists of Computer programs , which are sequences of instructions for the Computer. The process of writing programs is called Programming & individual Perform this task are called Programmers.

Two Types of Software System Software Application Software

System Software System Software is a set of one or more programs designed to control the operation & extend the processing capability of a computer system. A System Software are designed to make the computer easier to use. Eg- Operating system System software is a set of instructions that serves primarily as an intermediary between Computer Hardware & Application Programs.

It is useful for loading the programs when the Computer is turn on. Functions of System Software Supports development of other application software Supports execution of other application software Monitors effective use of various Hardware Communicate & Control the Peripheral Devices.

Hence System software makes the operation of a computer system more effective & efficient. It helps the hardware Components work together, & provides the support for the development & execution of application software. The programs included in a system software package are called System Programs. The programmers who prepare system software are referred to as a system programmers.

Some Commonly known types of System Software. Operating Systems Programming Language Translator Communications Software Utility programs

2) Application Software Application Software is a set of one or more programs designed to solve a specific problem, or to do a specific task. Eg- Examination result Processing Software, Railway/Airline Reservation Software, Computer Games Software. Similarly a program written by a scientist to solve a research problem is also Application Software. The Programs included in an application software package are called application software. The Programmers who prepare application software are referred to as application programmers.

They range from simple applications such as There are millions of software available for wide range of applications. They range from simple applications such as Word Processing Inventory Management Preparation of tax returns Banking Hospitals

Some Commonly known Application Software are Word processing Software Spreadsheet Software Database Software Graphics Software Personal Software Education Software Entertainment Software

Software Issues The Importance of Software in Computer Systems has brought new issues to the forefront for organizational Managers. These issues include Software Evaluation Selection of Software Software Licensing Software Upgrades Open System Open Source Software

Open Systems The Concept of open source systems refers to a model of computing products that work together, Achieving this goal is possible through the use of same Operating system with Software on all different computers that would interact with one another in an organization. A complementary approach is to produce application software that will run across all computer platforms,

Eg of Open Source software are Open source software is software made available in source code form at no cost to developers. Eg of Open Source software are Free Software Foundation (fsf.org) Send Mail SMTP (sendmail.org) Mozilla (mozilla.org)

ENTERPRISE RESOURCE PLANNING (Enterprise Software) ERP IS AN INDUSTRY TERM FOR THE BROAD SET OF ACTIVITIES SUPPORTED BY THE MULTI-MODULE APPLICATION SOFTWARE THAT HELP A MANUFACTURER OR THE BUSINESSES MANAGE THE IMPORTANT PARTS OF ITS BUSINESS , INCLUDING PRODUCT PLANNING , PARTS PURCHASING , MAINTAINING INVENTORIES , INTERACTING WITH SUPPLIERS , PROVIDING CUSTOMER SERVICE , TRACING ORDERS.

TRADITIONAL VIEW OF SYSTEMS A LARGE ORG TYPICALLY HAS MANY DIFFERENT KINDS OF INFORMATION SYSTEMS THAT SUPPORT DIFFERENT FUNCTIONS , ORGANIZATIONAL LEVELS , & BUSINESS PROCESS. TRADITIONAL VIEW OF SYSTEMS HUMAN RESOURCES MARKETING & SALES MANUFACTURING ACCOUNTING BUSINESS PROCESSES BUSINESS PROCESSES BUSINESS PROCESSES BUSINESS PROCESSES MANUFACTURING SYSTEMS HUMAN RESOURCES SYSTEMS ACCOUNTING SYSTEMS MARKETING & SALES SYSTEMS

ERP SYSTEMS SOLVE THIS PROBLEM BY PROVIDING A SINGLE INFORMATION SYSTEM FOR WHOLE ORGANIZATION. WE HAVE SEEN THE TRADITIONAL SYSTEM IN THAT THERE WERE DIFFERENT SYSTEM , BUT IN THIS ALL THE DIFFERENT DEPARTMENTS ARE INTERRELATED WITH EACH OTHER , ENTERPRISE SYSTEM COLLECTS DATA FROM VARIOUS KEY BUSINESS PROCESSES & STORE THE DATA IN A SINGLE SYSTEM. ENTERPRISE SYSTEMS CAN INTEGRATE THE KEY BUSINESS PROCESSES OF AN ENTIRE FIRM INTO A SINGLE SOFTWARE SYSTEM THAT ALLOWS INFORMATION TO FLOW THROUGH OUT THE ORGANIZATION. THESE SYSTEMS FOCUS PRIMARILY ON INTERNAL PROCESSES BUT MAY INCLUDE TRANSACTIONS WITH CUSTOMERS & VENDORS.

ENTERPRISE SYSTEM VENDORS CUSTOMERS MANUFACTURING ACCOUNTING HUMAN RESOURCES FINANCE SALES & MARKETING

ADVANTAGES OF ERP EASY TO USE READY MADE SOLUTION FOR MOST OF THE PROBLEMS EASY ENTERPRISE WIDE SHARING TIME SAVING NO WASTAGE OF RESOURCES.

FEATURES OF ERP ERP COVERS ALL THE FUNCTIONAL AREAS LIKE MANUFACTURING , SELLING & DISTRIBUTION. ERP HELPS IN INCREASING THE CUSTOMER SERVICE ERP ELIMINATES MOST OF THE BUSINESS PROBLEMS LIKE MATERIAL SHORTAGES , CUSTOMER SERVICES , CASH MANAGEMENT , INVENTORY PROBLEMS , QUALITY PROBLEMS ETC. ERP ALLOWS TO USE THE LATEST TECHNOLOGIES LIKE INTERNET , INTRANET , VIDEO CONFERENCING , E-COMMERCE ETC. ERP NOT ONLY ADDRESSES THE CURRENT REQUIREMENTS BUT ALSO USEFUL FOR THE FUTURE.

ERP PROVIDES BUSINESS SYSTEMS LIKE DSS & ESS ERP BRIDGE THE INFORMATION GAP ACROSS THE ORG.

Programming Languages A language acceptable to a computer system is called computer languages or programming languages. The process of writing instructions in such a language for is called programming or coding. Language is a means of communication. We use a natural language such as English to communicate our ideas & emotions to others. Similarly , a programmer uses a computer language to instruct a computer what he/she wants it to do.

All natural languages use a standard set of words & symbols for communication. The main difference between a natural language & a computer language is that natural languages have a large vocabulary but computer languages use a very limited vocabulary. Every problem to be solved by a computer has to be broken down into a simple steps. Every natural language has a systematic method of using the words & symbols in that language defined by the grammar rules of the language.

Similarly, the words & symbols of a computer language must also be used as per the set rules . Known as syntax rules, of the language. In case of natural language, one can use poor or incorrect vocabulary & grammar & still communicate his/her thoughts. However programming language the rules should be followed properly.

Three types of Programming Languages Machine Language Assembly Language High-level Language

Machine Language (1st generation language) Every Computer understands only one language without using a translation program. This language is called Machine language. The machine language is in the form of a binary i.e. 0s & 1s A machine language instruction normally has a two parts Operation code Operand code

Operation code that tells the computer what function to perform. Operand that tells where to store the data. Operations included in computer are 1) Arithmetic operation 2) Logical operation 3) Data movement operation Eg- To print a name in the paper having the code 1011001111101011

Obviously, this language is not easy to use because it is difficult to read & understand , & because it is written in a number system, which we are not familiar with. Advantages 1) Programs written in machine language can be executed very fast by a computer because machine instructions are understood by the computer without the need for any translation.

Limitations of machine language Difficult to program Error Prone Difficult to modify

2. Assembly Language(2nd generation language) Assembly language programming, introduced in 1952 By using alphanumeric codes instead of numeric codes for the instructions in the instruction sets Eg- ADD instead of 1110 With this feature programmers can remember easily By allowing addresses of fixed storage locations to be represented by alphanumeric names instead of numeric addresses.

Eg- Memory locations 1000, 1001 may be represented as FRST, SCND A language that allows instructions & storage locations to be represented by letters & symbols instead of numbers is called assembly language. A program written in an assembly language is called assembly program or symbolic program.

Assembly language program Input Output Machine Language Program Assembly language program Input Output Assembler

Advantages Easier to understand & use Easier to locate Easier to modify No worry about address Disadvantages Time consuming Difficult

3) High Level Language Procedural Languages Non-Procedural languages Natural Programming languages

Procedural Languages(3rd generation Language) Procedural Languages are the next step in the evolution of user oriented programming languages. This language is much closer to so-called natural language & therefore the easier to write , read & alter One statement in a procedural language is translated into machine language for making programming language more effective. Procedural language require the programmer to specify step by step exactly how computer will work.

Higher level language is translated into machine level language with the help of a Translator. Eg- FORTRAN , COBOL, C programming etc…..

Non Procedural Languages(4th generation language) Another type of high-level language, called nonprocedural languages, allow the user to specify desired result without having to specify the detailed procedures needed to achieve the result. An advantage of nonprocedural language is that they can be used by non-technical users to carry out specific task. It is very simple & it reduce the coding error. It is used for Database as query language , report generator

It is known as a Fifth generation languages or intelligent languages Natural Languages It is known as a Fifth generation languages or intelligent languages Visual Programming languages Hypertext Markup languages Virtual Reality Modeling languages Object Oriented Programming languages

Visual Programming Language Programming languages that are used within a graphical envt are referred as a Visual programming language. These languages use a mouse, icons, symbols on the screen. It makes programming language very easy. Eg- Visual Basic , Visual C++ Their easy of use makes them popular with non-technical user.

Hypertext markup Language Hypertext is an approach to data management in which data are stored in a network connected by links called hyperlinks. Eg- www It is very easy to get useful information

Virtual Reality Modeling Language It is used for creating Sound Video Image

Object-oriented Programming Languages Eg – C++ ,java