Chapter 4 Software Systems Application Software Chapter 4

Chapter 4 Software: Systems & Application Software Chapter 4 IS for Management

Software basics 4 Software is a critical piece of making computers perform 4 Businesses typically spend more on software than hardware 4 Computer programs are sequences of instructions for the computer Chapter 4 2 IS for Management

Two broad classes of Software 4 Systems Software 4 Set of programs that coordinate activities & functions of the hardware & various other programs 4 Application Software 4 Programs that help users solve particular computing problems Chapter 4 3 IS for Management

Software classified by “sphere of influence” Personal Information Software: Systems that serve the needs of an individual user (e. g. , wordprocessors, databases, spreadsheets) Workgroup Software: Systems that support two or more people who work together to achieve a common goal (e. g. , group scheduling, conferencing) Enterprise Software: Systems that support the firm in its interaction with its environment (e. g. , order entry, billing) Chapter 4 4 IS for Management

Software Issues & Trends 4 Software Licensing 4 Protection by software vendors to prevent unauthorized use 4 Software Upgrades 4 A revised version of software that usually includes fixes of known problems, plus enhancements to existing capabilities 4 Global Software Support 4 Software that is distributed around the globe may require unique support mechanisms due to local political & economic conditions Chapter 4 5 IS for Management

Role of Systems Software 4 An interface or buffer between application software & hardware 4 Operating System 4 Controls the hardware & acts as an interface with application programs Chapter 4 6 IS for Management

Operating System Functions 4 Perform common computer hardware functions 4 Provide a user interface 4 Provide a degree of hardware independence 4 Manage system memory 4 Manage processing tasks 4 Provide networking capability 4 Control access to system resources 4 Manage files Chapter 4 7 IS for Management

User Interfaces 4 User Interface 4 A function of the operating system that allows individuals to access & command the computer 4 Command-Based User Interface 4 Requires text commands to perform basic activities 4 Menu-Based User Interface 4 Requires pointing to menus & clicking on command 4 Graphical User Interface (GUI) 4 Uses pictures (icons) & menus displayed on the screen to send commands to the computer system Chapter 4 8 IS for Management

Software Concepts (1) 4 Hardware Independence 4 Operating systems provide hardware independence for application software 4 The application software interfaces with the operating system which Application interfaces with the hardware OS Hardware Chapter 4 9 IS for Management

Software Concepts (2) 4 Memory Management 4 Controls how memory is accessed & maximizes available memory & storage 4 Virtual Memory 4 Memory that allocates space in secondary storage to supplement the immediate, functional memory capacity of RAM 4 Paging 4 A function of virtual memory that allows the computer to store currently needed pages in RAM while the rest of these programs wait in secondary storage Chapter 4 10 IS for Management

Software Concepts (3) 4 Multitasking 4 A processing activity that allows a user to run more than one application at the same time 4 Multithreading 4 A processing activity that is basically multitasking within a single application 4 Time-sharing 4 A processing activity that allows more than one person to use a computer system at the same time Chapter 4 11 IS for Management

Software Concepts (4) 4 Network capability 4 Aids in connecting the computer to a network 4 Access to system resources 4 Provides security for unauthorized access 4 File management 4 Ensures that files in secondary storage are available when needed & are protected against unauthorized usage 4 Utility Programs 4 Merge & sort sets of data, keep track of computer jobs being run, compress files of data before they are stored or transmitted over a network, & perform other important tasks Chapter 4 12 IS for Management

Types of Application Software 4 Proprietary Software 4 Designed to solve a unique & specific problem 4 Can be developed in-house or developed under contract by an outside software provider 4 Customized Software 4 Blend of in-house & external development 4 Off-The-Shelf Software 4 An existing software program that can be used without considerable changes expected Chapter 4 13 IS for Management

Personal Application Software 4 Word Processing Program 4 Assistance in formulating, formatting, & printing documents such as letters, memos, & papers 4 Spreadsheet Program 4 Built-in functions for statistical, financial, logical, database, graphics, & data & time calculations 4 Database Program 4 Stores, manipulates, & retrieves data 4 Software Suite 4 Collection of personal productivity software such as word processor, spreadsheet, & database 4 Graphics Program 4 Assistance in making presentations, developing brochures, illustrations, etc. 4 On-Line Services 4 Provide access to various information resources Chapter 4 14 IS for Management

Object Linking & Embedding 4 Object Linking & Embedding (OLE) allows user to copy text/graphics from one document to another or to embed text/graphics from one program into another program/document 4 Server Application supplies objects user places in other applications 4 Client application accepts objects from other applications 4 Copy copies data from one application & places it in another 4 Link is used when user wants changes made to the server object to appear automatically in all linked client objects 4 Embed is used when user wants an object to become part of the client document Chapter 4 15 IS for Management

Workgroup Application Software 4 Group. Ware 4 Helps groups of people work together more efficiently & effectively 4 Collaborative Computing Software 4 Helps teams of people work together toward a common goal Chapter 4 16 IS for Management

Enterprise Software 4 Enterprise Application Software 4 Benefits the entire organization (e. g. , accounts receivable, accounts payable, general ledger, order entry, etc. ) 4 Enterprise Resource Planning (ERP) 4 A set of integrated programs that manage a company’s vital business operations for an entire multi-site, global organization (e. . g. , SAP, People. Soft, J. D. Edwards, Oracle, etc. ) Chapter 4 17 IS for Management

Programming Languages (1) 4 Machine Language 4 The first generation programming language 4 A low-level language because it involves a basic coding scheme using the binary symbols 1 & 0 4 Assembly Language 4 Second generation language 4 Replaced binary digits with symbols programmers could more easily understand 4 Third Generation Languages 4 Continued trend to more symbolic code (e. g. , COBOL, FORTRAN) Chapter 4 18 IS for Management

More Programming Languages 4 Fourth Generation Languages (4 GLs) 4 Less procedural & even more English-like than third-generation languages (e. g. , FOCUS) 4 Query Languages 4 Ask the computer questions in English-like sentences (aka database query languages) 4 Structured Query Language (SQL) 4 Standardized query language used to perform database queries & manipulations 4 Most modern database management system applications use or support SQL 4 Fifth-Generation Languages 4 Combines rule-based code generation, component management, visual programming techniques, & reuse management Chapter 4 19 IS for Management

Object Oriented Languages (Figure 4. 17) 4 Object Oriented Languages: Small Talk, C++, Java Chapter 4 20 IS for Management

Object Oriented Languages 4 Object-Oriented Languages allow interaction of programming objects, including data elements & the actions that will be performed on them 4 Encapsulation: The process of grouping items into an object 4 Polymorphism: A process allowing the programmer to develop one routine or set of activities that will operate on multiple objects 4 Inheritance: Property used to describe objects in a group of objects taking on characteristics of other objects in the same group or class of objects 4 Reusable Code: The instruction code within an object that can be reused in different programs for a variety of applications Chapter 4 21 IS for Management

Visual Programming Languages 4 Use a mouse, icons, or symbols on the screen & pulldown menus to develop programs 4 Examples: Visual Basic, Visual C++, PC COBOL 4 Knowledge-based Management Approach 4 User tells the computer what he/she wants the computer to do rather than how to do the job Chapter 4 22 IS for Management

Language Translation Language translator: Systems software that converts a programmer’s source code into its equivalent in machine language 4 Interpreter: A language translator that translates one program statement at a time into machine code 4 Compiler: A language translator that converts a complete program into machine language to produce a program that the computer can process in its entirety Chapter 4 23 IS for Management

Case 4 Gap uses object-oriented programming 4 pp. 184 -185 4 Next Class 4 Chapter 5 - Organizing data & information 4 Case: US West - Data warehousing Chapter 4 24 IS for Management