Systems analysis and design methods 7th whitten and benley chapter 02

Information System Building Blocks Introduction  The chapter will address the following questions:       What is the difference between data and information? What is the the product called an information system? What are six classes of information system applications and how they interoperate? What is the role of information systems architecture in systems development? What are four groups of stakeholders in information systems development and the unique role of the systems analyst in relation to the four groups? Could you be able to recognize categories of systems users and managers who become stakeholders in systems development? Information System Building Blocks Introduction  The chapter will address the following questions:      Can you differentiate between a perspective and a view as it relates to information systems architecture? What are four perspectives of the DATA focus for an information system? What are four perspectives of the PROCESS focus for an information system? What are four perspectives of the INTERFACE focus for an information system? What are four perspectives of the GEOGRAPHY focus for an information system? Information System Building Blocks A Review of Fundamentals of Information Systems  What is the difference between Data and Information?    Data are raw facts about the organization and its business transactions Most data items have little meaning and use by themselves Information is data that has been refined and organized by processing and purposeful intelligence Information Systems transform data into useful information  An information system is an arrangement of people, data, processes, interfaces, and geography that are integrated for the purpose of supporting and improving the day-to-day operations in a business, as well as fulfilling the problem-solving and decisionmaking information needs of business managers Information System Building Blocks A Review of Fundamentals of Information Systems  Information technology has significantly expanded the power and potential of most information systems  Information technology is a contemporary term that describes the combination of computer technology (hardware and software) with telecommunications technology (data, image, and voice networks) Information System Building Blocks A Review of Fundamentals of Information Systems  Transaction Processing Systems  Business transactions are events that serve the mission of the business  Transaction processing systems are information system applications that capture and process data about (or for) business transactions They are sometimes called data processing systems Information System Building Blocks A Review of Fundamentals of Information Systems  Management Information Systems  Management Information Systems supplement transaction processing systems with management reports required to plan, monitor, and control business operations  A management information system (MIS) is an information system application that provides for management-oriented reporting, usually in a predetermined, fixed format Information System Building Blocks A Review of Fundamentals of Information Systems  Decision Support Systems  Decision Support Systems are concerned with providing useful information to support the decision process   A decision support system (DSS) is an information system application that provides its users with decision-oriented information whenever a decision making situation arises When applied to executive managers, these systems are sometimes called executive information systems A DSS is designed to support unstructured decisions Information System Building Blocks A Review of Fundamentals of Information Systems  Decision Support Systems  A DSS provides one or more of the following types of support to the decision maker:      Identification of problems or decision making opportunities (similar to exception reporting) Identification of possible solutions or decisions Access to information needed to solve a problem or make a decision Analysis of possible decisions, or of variables that will impact a decision Sometimes this is called ‘what if’ analyses Simulation of possible solutions and their likely results Information System Building Blocks A Review of Fundamentals of Information Systems  Decision Support Systems  A DSS can utilize a Data Warehouse  A data warehouse is a read-only, informational database that is populated with detailed, summary, and exception information that can be accessed by end users and managers with DSS tools that generate a virtually limitless variety of information in support of unstructured decisions Information System Building Blocks A Review of Fundamentals of Information Systems  Expert Systems  Expert Systems are an extension of the decision support system   An expert system is an information system application that captures the knowledge and expertise of a problem solver or decision maker, and then simulates the ‘thinking’ of that expert for those who have less expertise Expert systems are implemented with artificial intelligence technology, often called expert system shells 10 Information System Building Blocks Building Blocks - Expanding The Information System Framework  Building Blocks of Interfaces  System Users’ View of Interfaces  System users are most interested in what has come be called the user interface to the system • The user interface defines how the system users directly interact with the information system to provide inputs and queries, and receive outputs and help  The explosive growth of personal computers, combined with the popularity of graphical user environments such as Microsoft Windows (for Intel-based PCs) and Apple Macintosh (for Motorola-based PCs) has created a defacto standard – the graphical user interface 43 Information System Building Blocks Building Blocks - Expanding The Information System Framework  Building Blocks of Interfaces  System Designers’ View of Interfaces  System designers must be concerned the details of both user and system interfaces  System designers are concerned with consistency, completeness, and user dialogues of user interfaces • User dialogues describe how the user moves from screen-toscreen, interacting with the application programs to perform useful work  System designers view the interface in terms of interface properties, system states, events that change the system states, and responses to events • Collectively, this is called the interface schema 44 Information System Building Blocks Building Blocks - Expanding The Information System Framework  Building Blocks of Interfaces  System Designers’ View of Interfaces (continued)  System designers are concerned with system-to-system interfaces  System designers have to design the system-to-system interfaces that allow a new information system to transparently interoperate with previously designed systems 45 Information System Building Blocks Building Blocks - Expanding The Information System Framework  Building Blocks of Interfaces  System Builders’ View of Interfaces  System builders construct, install, test, and implement both user and system interfaces • For user interfaces, the technology is usually embedded into the programming language environments used to construct the computer processes • System interfaces are considerably more complex to construct and may utilize system interfacing technologies such as middleware – Middleware is a layer of utility software that sits in between applications software and systems software to transparently integrate differing technologies so that they can operate 46 Information System Building Blocks Building Blocks - Expanding The Information System Framework  Building Blocks of Geography   Information systems geography describes:  the distribution of DATA, PROCESSES, and INTERFACES (the other building blocks) to appropriate business locations  the movement of data and information between those locations The inclusion of GEOGRAPHY in the framework is driven by the trend towards distributed computing  Distributed computing is the decentralization of applications and databases to multiple computers across a computer network 47 Information System Building Blocks Building Blocks - Expanding The Information System Framework  Building Blocks of Geography  The most popular application of distributed computing is called client/server computing  In a client/server computing application, information system building blocks are distributed between ‘client’ personal computers and ‘server’ shared computers The clients and servers effectively interoperate to share the overall workload 48 Information System Building Blocks Building Blocks - Expanding The Information System Framework  Building Blocks of Geography  Distributed computing is being driven by several trends  Organizations that can gain faster access to critical information have a competitive advantage  Organizations that can extend their information systems to include their customers and suppliers have a competitive advantage  Organizations operate in more locations, national and international, then ever before 49 Information System Building Blocks INFORMATION SYSTEMS FRAMEWORK FOCUS ON SYSTEM DATA FOCUS ON SYSTEM PROCESSES FOCUS ON SYSTEM INTERFACES FOCUS ON SYSTEM GEOGRAPHY Business Subjects Business Functions System Context Operating Locations Data Requirements Business Process Reqts Input/Output Reqts Communication Reqts SYSTEM OWNERS (scope) S Y S T E M A N A L Y S T S (facilitation) EDI C us t SYSTEM USERS orde r S t Louis HQ ca ta log cha nge s s hip orde r We s t C us tom e rs Produc ts Ca ta log Ea s t C us tom e rs cre dit cre dit (requirements) LA Office s hip orde r Indy Wa re hous e s hip orde r NY Office s e rvice Ma inte na nc e R e cords Database Scehma Application Schema Interface Schema Network Schema C om m unica tions C ontrolle r SYSTEM DESIGNERS S t Louis Ma infra m e NT S e rve r LA PB X (specification) NT S e rve r NY Ethe rne t LA N/NT Ethe rne t LA N/NT Indy AIX S e rve r C lie nt PC Database Structures Application Programs Component Programs C lie nt PC Clie nt PC C lie nt PC Ente rne t LA NA IX/La n Ma na ge r Network Programs Cre a t e Ac c o unt Type = Sale sClerk Se t Orde rDir.Right s= f ull Se t Cus t o me rDir.Right s = f ull Se t Pro duc t Dir.Right s = rea d Se t Orde rAppDir.Right s = c o py SYSTEM BUILDERS (components) Database Technology Software (and Hardware) Technology 50 Interface Technology Networking Telchnology Information System Building Blocks  Building Blocks - Expanding The Information System Framework Building Blocks of Geography  System Owners’ View of Geography  The system owner views the geography in terms of operating locations  The system owners will ultimately decide the degree to which the system will be centralized, distributed, or duplicated 51 Information System Building Blocks  Building Blocks - Expanding The Information System Framework Building Blocks of Geography  System Users’ View of Geography  System users are the experts about the requirements for any given location  System users are interested in operating locations  System users tend to have a more microscopic view of locations  System users think in terms of communications requirements • Communications requirements define the information resource requirements for operating locations, and how different operating locations need to communicate with one another These communication requirements are expressed independent of any specific technology is or can be used to implement them 52 Information System Building Blocks  Building Blocks - Expanding The Information System Framework Building Blocks of Geography  System Designers’ View of Geography  System designer's view of GEOGRAPHY is influenced and/or constrained by the limitations of specific technology  System designer's view of GEOGRAPHY is depicted via a network schema that can support the business network • A network schema (also called a network configuration or topology) is a technical model that identifies all of the computing centers, computers, and networking hardware that will be involved in a computer application  System designer's view of networks is technical 53 Information System Building Blocks  Building Blocks - Expanding The Information System Framework Building Blocks of Geography  System Designers’ View of Geography (continued)  Given the network schematic, the designer’s job is to determine the optimal distribution of DATA, PROCESSES, and INTERFACES across the network • This is called application partitioning  The system designer's intent is to prepare specifications that: • fulfill the business network requirements of the users • provide sufficient detail and consistency for communicating the network design to the system builders 54 Information System Building Blocks  Building Blocks - Expanding The Information System Framework Building Blocks of Geography  System Builders’ View of Geography  System builders use telecommunications languages and standards to write network programs • Network programs are machine-readable specifications of computer communications parameters such as node addresses, protocols, line speeds, flow controls, security, privileges, and other complex, networking parameters 55 Information System Building Blocks INFORMATION SYSTEMS FRAMEWORK SYSTEM OWNERS (scope) FOCUS ON SYSTEM DATA FOCUS ON SYSTEM PROCESSES FOCUS ON SYSTEM INTERFACES FOCUS ON SYSTEM GEOGRAPHY Business Subjects Business Functions System Context Operating Locations Cus t o me rs o r de r z er o , o ne , o r mo r e pr o duc t s Pr o duc t s ma y be o r der e d by z e ro , o ne , o r mo re c us t o me r s Acco unts R eceivable Database Ma rke ting Credit Adve rtising Custo mer S a le s Or der Manag ement System Or der P icking Or der War eho use Credit Vo ucher O rde rs Ca nce lla tions S e rvice s Chapters 5, Chapters 5, Chapters 5, Bank Chapters 5, Data Requirements Business Processes Interface Requirements Communication Reqts rejected o rder S Y S T E M A N A L Y S T S (facilitation) SYSTEM USERS (requirements) SYSTEM DESIGNERS (specification) PRODUCT product-no product-na me unit-of-me a s ure unit-price qua ntity-a va ila ble CUS TOMER cus tome r-no cus tome r-na me cus tome r-ra ting ba la nce -due Validate custo mer o rder with vali d pro ducts valid o rder o rder witho ut valid custo mer appro ved o rder Vali date pro ducts Pro ducts quantity in sto ck Release o rder Shutdown R outine Validate an Order Fi le an O rder NY Office Maintenance R eco r ds Chapters 5, Interface Schema Network Schema Customer For m New Customer P rocess an Order ship or der Chapters 5, 13, 14 Log o n G et an O rder Indy Wareho use ser vice Order P rocessing P rogram Initiation R outine ship o rder picking ticket Application Schema Or der Accepted Chang e of Addr ess New Order Co mmunicatio ns Co ntr o ller S t Lo uis Mainfr ame NT S erver LA Order Help Co mplete Or der Fo r m R equest Or der Help Database Technology P r oducts Catalo g East Custo mer s cr edit LA Office Database Scehma P RODUCT CUS TOMER product_no [Alpha (10)] INDEX cus tome r_no [Alpha (10)] INDEX product_na me [Alpha (32)] cus tome r_na me [Alpha (32)] unit_of_me a s ure [Alpha (2)] cus tome r_ra ting [Alpha (1)] INDE X unit_price [Re a l(3, 2)] ba la nce _due [Re a l(5,2)] qua ntity_a va ila ble [Inte ge r(4 )] any good DB course catalog chang es cr edit Orders appro ved o rder prices Chapters 5, CREATE TABLE CUSTOM ER (cus tomer_no CH AR(10) N OT N ULL cus tomer_name CH AR(32) N OT N ULL cus tomer _rating CH AR(1) N OT N ULL balance_due DECIM AL(5,2) CREATE IN DEX cus t_no_idx on CUSTOMER CREATE IN DEX cus t_rt_idx on CUSTOM ER St Lo uis HQ ship or der West Customer s Chapters 5, ORDER_PRODUCT ORDER orde r_no [Alpha (12)] INDE X ORDER.orde r_no P RODUCT product_no orde r_da te [Da te (mmddyyyy) qua ntity_orde re d [Inte ge r(2) CUS TOMER cus tome r_no o r der Fi r ecr acker Sal es o rder Database Structures (components) EDI Cust Check credit custo mer number ORDER orde r-no orde r-da te products -orde re d qua ntitie s -orde re d Chapter 12 SYSTEM BUILDERS credit Custo mers Check Customer Credit Check P roduct Data Check Credit Data R elease an Order Help + Fir st Order R equest P ro duct Lo okup P BX NT S er ver NY E ther net LAN/NT E ther net LA N/NT R equest P r oduct Loo kup Help IndyAIX Ser ver O rders P r oduct Lo o kup Help Co mplete P roduct Loo kup Chapters 11, 16 Chapters 11, 13, 14, 15 Application Programs Component Programs Customers P roducts VALI DATE_AN_ORDER REPEAT UNTI L NO_MORE_ORDERS PERFORM CUSTOMER_VALI DATI O REPEAT UNTI L NO_MORE_ORDER PERFORM PRODUCT_VALI DATI END REPEAT PERFORM CREDI T_CHECK I F CREDI T_CHECK 'BAD' THEN any good programming course Software (and Hardware) Technology 56 O n Eve n t H e l p B ut to nC l i c k D o C ng e F o c us H e l p D i a l o g O n Eve n t O K B ut t o n D o Beg i n {p ro e c d ure } En d O n Eve n t C a nc e l B ut t o n D o any good programming course Interface Technology Client P C Client P C Client P C Client P C E nter net LANAIX/Lan Manag er Chapter 11 Network Programs Cre ate Ac c ou ntType = Sa l e s Cl e rk Se t Ord e rDi r Ri g hts=fu l l Se t Cu stome rDi r Ri g hts =fu l l Se t Prod u c tDi r Ri g hts =re a d Se t Ord e rAppDi r Ri g hts =c opy any good data communication course Networking Telchnology Information System Building Blocks Summary      Introduction A Review of Fundamentals of Information Systems A Framework For Information Systems Architecture Perspectives - The People Side of Information Systems Building Blocks - Expanding The Information System Framework 57 ... Fundamentals of Information Systems  Personal and Work Group Information Systems  Personal and Work Group Information Systems typically are built using personal computer technology and software   Personal... Personal information systems are those designed to meet the needs of a single user They are designed to boost an individual’s productivity Work group information systems are those designed to meet... SCOPE (purpose and vision; goals and objectives; costs and benefits) SYSTEM USERS INFORMATION SYSTEM REQUIREMENTS (WHAT the system "is" and "must do" independent of technology) SYSTEM DESIGNERS INFORMATION