4478-1685002066930-Unit_7.1_What is Software.pdf

Unit 7 – Software Engineering 7.1 What is Software? 1 A Software is…  Instructions (Computer Programs) : That when executed provide the desired performance.  Data Structures (Collection of Data) : That enable the programs to adequately manipulate Infor...

Unit 7 – Software Engineering 7.1 What is Software? 1 A Software is…  Instructions (Computer Programs) : That when executed provide the desired performance.  Data Structures (Collection of Data) : That enable the programs to adequately manipulate Information. ex: Fee, DoB, Price, Amount  Documents : That describe the operation and the use of the programs.  Therefore SOFTWARE is not just a single element, it’s a Package 2 Classification of Software Classification 1 – Based on usage System Software Application Software Classification 2 – Based on how they are developed Generic Products (Off-the Shelf Products) Bespoke Products (Custom built Products) 3 System Software Directly controlling the Hardware Resources (Memory, CPU & Disk Storage Management) & supports the operation of Application Software. Such software includes:  Operating Systems (Windows 7, Vista)  Program Translators (Interpreters, Compilers)  Utility Software (Virus Scanner, Disk Defragmenter, Disk cleanup) 4 Application Software Serves the User Requirements in a particular application domain (Particular Business). They are used to carry out user’s specific data processing tasks. Can be categorized as..  Business Software  Scientific & Engineering Software  Real time Software  Embedded Software  Personal Computer Software  Artificial Intelligence Software 5 Application Software Cont..  Business Software :.e.g: Accounting, Payroll, Stock Control, Office Work-MS Office  Scientific & Engineering Software :.e.g: CAD (Computer Aided Designing) CAM (Computer Aided Manufacturing)  Real time Software : e.g: Fire detection  Embedded Software : e.g: Software in Motor vehicle  Personnel Computer Software : e.g: Office Package, Excel  Artificial Intelligence Software : e.g: Robotics 6 Types of Software Products Generic Products (Off-the Shelf Products) Bespoke Products (Custom built Products) 7 Generic Products Off-the Shelf Software / Ready-made Software Information systems which are produced by a development organization and sold on the open market to any customer who is able to buy them. ex: Payroll Systems, Point Of Sales systems, Stock Control Systems, MS Office Package No Development Time Fast implementation 8 Bespoke Products Custom-built Software / Tailor-made Software Systems which are requested by a particular customer. The software is developed specifically for that customer by some contractor ex : A student management system specifically written for a college ex: for ESOFT Implementation is slower due to Development time Too costly as the total cost born by one Customer 9 Generic vs Bespoke 10 Software Quality Features.. Feature Description Maintainability It should be possible to evolve(modify/upgrade) software to meet the changing needs of the customers. To support this, the S/W should be well documented, easy to follow, must have comments to explain Dependability Includes a range of characteristics such as reliability(must not crash), safety(must not do something unsafe) security(Protection). Dependable software should not cause physical or economic damage in the event of system failure. Efficiency S/W should not make wasteful use of resources such as Memory & Processor time ex: the program must run fast & must use memory efficiently Usability S/W should have an appropriate user interface(GUI) & adequate documentation.(User Guide) 11 Lesson Summary  What is Software  Software Classification  System Software vs Application Software  Generic products vs Bespoke products  Software Product Attributes 12