งานนำเสนอเรื่อง: "1 Introduction to System Development Introduction : Have you ever seen newspaper headlines similar to the following ? • IRS Computer Audit Record Number."— ใบสำเนางานนำเสนอ:
1 Introduction to System Development Introduction : Have you ever seen newspaper headlines similar to the following ? • IRS Computer Audit Record Number of Tax Returns • Computer Skills Needed for Today’s Jobs • Computer Failure Halts Shuttle Launch • Wall Street Computer Handle Growing Stock Trading Volume Newspaper headlines are not our only view of today’s widespread use of computers. The use of computers in today’s world is commonplace. We take computers for granted and expect them to work perfectly; that is, to be reliable, fast, accurate, and easy to use.
2 Systems and procedures As it conducts its business, a company performs many functions in a specified manner. • A procedure is defined as the series of steps followed in a regular, specified order to accomplish one end result. One procedure for company is the writing of employee payroll checks, and a second procedure is the filling of customer orders. • A system is defined as a set of procedures used to accomplish specific results.
4 Example Systems •Student Record Management System –A computerised system that manages information concerning courses on offer at Brookes and Students registered to take one of more of those courses. •Library Loan System –A computerised system that manages the issuing and recall of library books. • Car Park Management –A paper (form)-based system for managing the allocation of parking spaces to visitors
5 Examples (cont.) •Traffic Management System –A system of interconnected components (roundabouts, traffic light, calming devices) to manage the flow of traffic through … •Chemical Process Control –A system based on feedback and control to manage the manufacturing of …. •The Respiratory System –The physiological system which enables the act or process of breathing in animals
6 Key Ideas •Many failed systems were abandoned because analysts tried to build wonderful systems without understanding the organization. •The primarily goal is to create value for the organization.
7 Simple system model Data processing Information input - manual output - computerize - knowledge
8 System inputs are called data, and system output are called Information. Data : defined as raw facts and figures, are the raw materials of the system. Information : defined as data processed for someone’s use, represents the finished goods of the system. The objective of processing is to ensure the validity of the incoming data and to convert valid data into timely and accurate information. A system may be called an information system, an application, or an application system.
9 Information system components Data People Procedure Hardware Software Files Information
10 People - include both management and end users Procedures- the tasks performed by all the people Hardware - computers, scanners, printer, and noncomputer equipment Software- system software - DOS, Windows, and UNIX - application software Files- the retained data is stored in files and databases on computer An information system is the collection of data, people, procedures, hardware, software, files, and information required to accomplish an organized set of functions.
12 Wisdom "Wisdom is not a product of schooling but of the lifelong attempt to acquire it.“ Albert Einstein
13 Business information systems Each business organization sells specific products or services and has specific goals, methods, and information system requirements that are set in the organization’s underlying corporate culture. A company’s corporate culture is the set of beliefs, rules, traditions, values, and attitudes that give a company its atmosphere or personality and govern its way of doing business. In order to create an effective information system for a company, you must understand the information system’s requirements and the company’s goals, methods, and corporate culture.
14 Although there are a variety of types of business organizations in operation in the world today, companies are generally classified into two basic types: • Industrial, or production- oriented companies, which produce, sell, and distribute goods • service companies, which sell and distribute goods, services, or information The total business information system of a company normally consists of a series of subsystems, many of which are common to all business organizations.
15 Purchasing Systems Vendor Selection Ordering Electronic Buying Receiving Inspection Accounts Payable Human Resource Systems Employee Selection Compensation Analysis Benefits Projections Employment History Skills Inventory Production Systems Raw Materials Production Scheduling Finished Goods Costing Packaging Shipping and Distributing Finance Systems General Ledger Payroll Cost Accounting Budgeting Portfolio Analysis Marketing Systems Customer Order Entry Pricing Sales Analysis Advertising Performance Forecasting Receivables Systems Customer Invoicing and Billing Cash Receipts Accounts Receivable
16 Four characteristics of business information systems help to define their complexity. 1. Information systems are related to other information systems. 2. A boundary between two systems is where one system ends and the other system begins. 3. In addition to the common business information systems, there are many specialized information systems. At a school, specialized information systems handle class registration, class room scheduling, student grading, student loans, and transcript processing.
17 4. Large and small companies in the same industry have significant differences in their information system requirements.
18 Types of information systems The types of information systems that use a computer fall into six broad categories: • Operation systems (transaction processing system) • Management information systems (MIS) • Decision support systems (DSS) • Executive information systems (EIS) • Expert systems (ES) or Artificial intelligence (AI) • Office automation systems (OAS) • The integration of information systems
19 Organization levels Information is a company asset, as are employee, equipment and buildings, materials, and money. Information systems exist to provide this information asset to people in the organization. Information requirements vary widely, depending on the person’s responsibilities and position within the company. All companies organize in the way shown in figure; operational personnel report to lower management, who report to middle management, who report to top management.
20 Top Manage ment (Strateg ic) Middle Manage ment (Tactical) Lower Management (Supervisory) Operational Personnel (Functional) Organizatio n levels
21 Organization Responsibility Decision Information Systems Level Making Requirements Top Develop long-range Unstructured Executive information systems Management goals, plans and MIS summaries strategies Decision support systems Office automation systems Middle Develop short-range Semi- structured MIS summaries and exceptions Management goals, plans, and Decision support systems tactics Office automation systems Lower Develop day-to-day Structured Operational systems details Management plans and supervise Some MIS summaries and operational personnel exceptions Office automation systems Operational Perform routine Structured Operational systems details Personnel function Expert systems Office automation systems
23 Integrating Technologies for Systems 1. Ecommerce Applications and Web Systems - Increasing user awareness of the availability of a service, product, industry, person, or group. - The possibility of 24-hour access for users. 2. Enterprise Systems - Service-oriented architecture (SOA) - Enterprise resource planning (ERP) 3. Systems for Wireless and Mobile Devices 4. Open Source Software (OSS)
24 ESS GDSS CSCW S ES, DSS, MIS KWS, OAS TP S Wireless Systems Enterprise Systems Ecommerce and Web Systems
25 Information systems department The structure of the information systems department varies among companies, as does its name and its placement within the organization. Director Information Systems Manager Operations Manager Technical Support Manager Applications Manager Information Center
26 Maxim The organization that has the best information, knows where to find it, and can utilize it the quickest wins.
27 Data Quality Factors Accuracy Whether the value of each item of data is correct Timeliness Whether the data are up-to-date Consistency Whether the data in one part of the database have a common, appropriate set of controls to related concepts stored elsewhere
28 Data Quality Factors Transparency of meaning Whether the context for the data is clearly and commonly understood by all those with a legitimate interest Availability Whether the people who need the data can actually access it
29 System definition : set of interrelated and interacting elements that work together to accomplish specific purposes. structure : inputs, processes, outputs, feedback, environment, decision maker. subsystem : a system within a system. system performance : effectiveness (doing the right thing),efficiency (doing the thing right), cost, complexity, and control.
30 Effectiveness and Efficiency Two Major Classes of Performance Measurement • Effectiveness is the degree to which goals are achieved Doing the right thing! • Efficiency is a measure of the use of inputs (or resources) to achieve outputs Doing the thing right!
32 Inputs are elements that enter the system Processes convert or transform inputs into outputs Outputs describe finished products or consequences of being in the system Feedback is the flow of information from the Output to the decision maker, who may modify the inputs or the processes (closed loop) The Environment contains the elements that lie outside but impact the system's performance
34 Modeling a system Model = abstraction of reality - narrative models - physical models - schematic models - mathematical models F = X 2 + Y 2
35 Systems Analysis and Design: What is it? •Systems analysis: the systematic study of the information needs and problems of some organizational domain in order to recommend improvements and specify the business requirements for the solution. •Systems design: the specification of a technical, computer-based solution for the business requirements identified in a systems analysis
36 Systems Analysis and Design: Why is it? •Many information systems fail, because of: lack of reliability lack of usability not what the users wanted incompatible with other systems •SA&D addresses all but the first problem •SA&D is also long-term approach to ensure the overall effectiveness of IT in the organization
37 A systems analyst studies the information problems and needs of an organization to determine how to best solve the problems and accomplish improvements using information technology. –improved business processes –improved information systems –improved computer applications Systems Analysis and Design: Who is it?
38 Roles of the Systems Analyst : –Consultant (outsider) –Supporting Expert (insider) –Agent of Change (shaker) Systems Analysis and Design: Who is it?
39 Systems Analysis and Design: Where is it? Not just for businesses! –non-profit organizations –government agencies –educational institutions
40 •The systems analyst is a key person analyzing the business, identifying opportunities for improvement, and designing information systems to implement these ideas. •It is important to understand and develop through practice the skills needed to successfully design and implement new information systems. Key Ideas
41 •Analytical •Technical •Management •Interpersonal Qualities and Skills of a Systems Analyst
42 • Required skills and background • Working Knowledge of Information Systems and Technology • Computer Programming Experience and Expertise • General Business Knowledge • Problem-Solving Skills • Interpersonal Communications Skills • Interpersonal Relations Skills • Flexibility and Adaptability • Character and Ethics • Systems Analysis and Design Skills
43 Who is system analyst? User System analyst Programmer
45 General System Model of the Firm Physic al resour ces Input resour ces Output resour ces Physic al resour ces Transfor mation process Manage ment Standard s Informati on Processor ENVIRONM ENT Informat ion Decision s Inform ation and data
51 Who Are the Players in Systems Development? •User(s) •Business manager(s) •Steering committee •Application programmers •System programmers •Database, network, and other technology specialists •Security / auditing staff •Human factors experts •Documentation specialists