面向对象系统分析与设计 Object-Oriented Systems Analysis and Design

面向对象系统分析与设计 Object-Oriented Systems Analysis and Design
河北农业大学信息科学与技术学院滕桂法教授

主要内容 1、系统分析与设计概论 2、面向对象概念与术语 3、面向对象分析与设计 4、面向对象编程 5、UML面向对象设计基础

第一章系统分析与设计概论 (System Analysis and Design)
Chapter Objectives(You should be able to) 1. Define a system, information system, and automated information system. 2. Define the basic components and the basic characteristics of an automated information system. 3. Define system analysis and design and discuss why it is a difficult human endeavor. 4. Describe the skills and activities of a system analyst.

系统分析与设计概论 (System Analysis and Design)
5. Describe a general model of the analysis, design, and implementation process. 6. Discuss systems analysis and design as a career. 7. Discuss what a system analyst does. 8. Discuss systems analysis and design projects and where they come from. 9. Discuss the need for creating information systems requirements specifications.

10. Define and describe the information systems life cycle. 11. Define and describe the information system development life cycle. 12. Discuss the principles used to guide system analysis and design.

Development Process ◆ Systems planning ◆ Systems analysis ◆ System design ◆ Systems implementation ◆ Systems evolution

2. Concept of System Analysis and Design ◆ What is a system? A system is a set of interrelated components, working together for a common purpose. There are two types of systems: natural and fabricated.

System Model with Six Components: boundary system processing controls inputs feedback outputs

◆ What is an information system? An information system is a type of fabricated system that is used by one or more persons to help accomplish a task or assignment.

◆ What is an information system? people data procedures

◆ What is an automated information system? A automated information system is an information system that incorporates the use of computer hardware and software as part of the system.

◆ What is an automated information system? data people procedures software hardware

◆ What are the basic characteristics of an information system? The basic characteristics that exist within an information system are data, functions, and behavior, as illustrated in the following figure. Data Functions Behavior

◆ What are the basic characteristics of an information system? Data: input, stored, or output Function: business activity performed Behavior: the observable effects of a request

◆ What is systems analysis and design? System analysis and design is about developing software, but it is more about developing a complete automated information system, which includes hardware, software, people, procedures, and data. These five components exist in virtually all automated information systems, although the amount of each will vary with respect to the specific system being developed. All of these components must be considered and addressed during system analysis and design.

◆ Actors of systems analysis and design? System Analyst; System Engineer; Programmer; Architect;

系统分析与设计过程

◆ What makes systems analysis and design such a difficult human endeavor? Seven reasons: 1. Analysis problems, at their inception, have ill-defined boundaries and structure(users are not certain of what they want), and have a sufficient degree of uncertainty about the nature of the solution.

◆ What makes systems analysis and design such a difficult human endeavor? 2. The solutions systems analysts come up with to solve the problems are artificial, and since they are designed by humans with different backgrounds, experiences, biases, and so on, there exists an endless variety of potential solutions. That means that there is no single correct solution to a problem. Many needs and Many solutions.

◆ What makes systems analysis and design such a difficult human endeavor? 3. Analysis problems are dynamic. No business is standing still. Change! 4. The solutions to analysis problems require interdisciplinary knowledge and skills, hence, the need for a team approach to IS development. Emphasis on the partnership concept between the user community and the IS developers.

◆ What makes systems analysis and design such a difficult human endeavor? 5. The knowledge base of the systems analysis is continually evolving. As the apprentice systems analyst progresses through the junior, associate, and senior systems analyst ranks over time, he or she continues to learn more about business problem domains as well as improving his or her analytical skills and software development tool and technique skills.

◆ What makes systems analysis and design such a difficult human endeavor? 6. The process of analysis is primarily a cognitive activity in that we are asked to (1) put structure to an abstract problem domain, (2) process diverse information from a variety of users, and (3) develop a logical and consistent specification that will lead to the creation of a successful information system. 7. The People! Study human and org. behavior.

Stakeholders: Players in the Systems Development Team
A stakeholder is any person who has an interest in an existing or new information system. Stakeholders can be technical or nontechnical workers. For information systems, the stakeholders can be classified as ( six groups of information workers): System owners System users Systems analysts System designers System builders IT vendors and consultants Conversion Notes The classification scheme (system owners, system users, et al.) was moved up from Chapter 2 in the fourth edition. Teaching Tips You might want to remind students that a single individual can play multiple roles in a project. For example: A person could be both a system owner and system user. Many systems analysts are also system designers and builders. It is sometimes useful to identify individuals who might play the various roles in a typical information system.

Information versus Knowledge Workers
Information workers are those workers whose jobs involve the creation, collection, processing, distribution, and use of information. (In USA they are so called) Knowledge workers are a subset of information workers whose responsibilities are based on a specialized body of knowledge. (College educated; Depending on information and ability to properly use and react to information) Teaching Tips Give examples of information workers and knowledge workers to reinforce the difference. Footnote – Information workers (sometimes called “white-collar workers”) have outnumbered blue-collar workers since 1957. Typically a knowledge worker has a degree or credential in some subject area (hence, they are often called “subject area experts”). Examples include engineers, scientists, accountants, lawyers, etc.

Teaching Notes This is the first “chapter map” for the book. Each chapter will include a chapter map that visually maps the chapter to our adaptation of John Zachman’s Framework for Information Systems Architecture. The complete map will be built over the course of the first three chapters. Chapter 1 emphasizes the stakeholders column. Conversion Notes The only change in the stakeholders column from fourth edition was the addition of the external influence from and the participation of “IT Vendors and Consultants.”

System Owners System owners are the information system’s sponsors and chief advocates. They are usually responsible for funding the project to develop, operate, and maintain the information system. No additional notes

System Users System users are the people who use or are affected by the information system on a regular basis—capturing, validating, entering, responding to, storing, and exchanging data and information. A common synonym is client. Types include: Internal users Clerical and service workers Technical and professional staff Supervisors, middle managers, and executive managers Remote and mobile users (internal but disconnected) External users (customer and other system users) Teaching Tip Update students on the trend of “telecommuting.” Telecommuting falls into our “Remote” users category. Some students may confuse “remote users” and “external users.” The difference is that remote users work for the organization in question, while external users work for some other organization (or are direct consumers). The growth of the Web is driving the increase in both remote and external users.

System Designers and System Builders
System designers translate system users’ business requirements and constraints into technical solutions. They design the computer files, databases, inputs, outputs, screens, networks, and programs that will meet the system users’ requirements. System builders construct the information system components based on the design specifications from the system designers. In many cases, the system designer and builder for a component are one and the same. Teaching Notes Programmers are typically viewed as system builders, but in fact, they are also system designers since good programmers design the software they build. In reality, most technical specialists serve in most roles. For instance, database specialists typically design and construct databases.

Systems Analysts A systems analyst studies the problems and needs of an organization to determine how people, data, processes, communications, and information technology can best accomplish improvements for the business. When information technology is used, the analyst is responsible for: The efficient capture of data from its business source, The flow of that data to the computer, The processing and storage of that data by the computer, and The flow of useful and timely information back to the business and its people. Teaching Notes Actually, we offered two definitions in the chapter. First, we characterized the systems analyst as a “facilitator” of the other stakeholders’ participation in systems development. Then we offered the more precise definition in this slide.

Variations on the Systems Analysts Title
A business analyst is a systems analyst that specializes in business problem analysis and technology-independent requirements analysis. A programmer/analyst (or analyst/programmer) includes the responsibilities of both the computer programmer and the systems analyst. Other synonyms for systems analyst include: Systems consultant Systems architect Systems engineer Information engineer Systems integrator Conversion Notes We dropped “application analyst” and “information analyst” as variations described in the previous edition. It has become much less common. Teaching Notes Business analyst is becoming more popular because of the number of end-users and other knowledge workers being assigned to systems analysts roles in organizations.

Problem-Solving Scenarios
True problem situations, either real or anticipated, that require corrective action Opportunities to improve a situation despite the absence of complaints Directives to change a situation regardless of whether anyone has complained about the current situation Teaching Tips It can be useful to present examples of each scenario from the instructor’s personal experiences. The classification scheme is not mutually exclusive; that is, a project can be driven by multiple instances and combinations of problems, opportunities, and directives. a problem might be classified as both a true problem an opportunity, or an opportunity plus directive.

General Problem-Solving Approach
1. Identify the problem. 2. Analyze and understand the problem. 3. Identify solution requirements or expectations. 4. Identify alternative solutions and decide a course of action. 5. Design and implement the “best” solution. 6. Evaluate the results. If the problem is not solved, return to step 1 or 2 as appropriate. Conversion Notes We replaced the phase-like naming of the problem-solving steps introduced in Chapter 1 of the 4th edition (p. 9). This should prevent some students and instructors from confusing these problem-solving steps with an actual system development life cycle or methodology (introduced in Chapter 3).

Where Systems Analysts Work
In traditional businesses Working in traditional information services organizations (permanent project teams) Working in contemporary information services organizations (dynamic project teams) In outsourcing businesses Contracted to traditional businesses In consulting businesses In application software businesses Building software products for traditional businesses No additional notes

Traditional IS Services Organization
Teaching Tips The key characteristic of the traditional organization is the permanent assignment of analysts and programmers to a specific business function or area. The figure shows only analysts and programmers assigned to one team, “manufacturing systems.” Space prevented us from showing that there would also be a team of analysts and programmers for each of the other functional areas: marketing and financial.

Contemporary IS Services Organization
Conversion Notes We tried to greatly simplify this figure from the previous edition. The key change was to note how analysts, programmers, and other specialists are “pooled” for dynamic and temporary assignments to project teams as needed.

Business Trends and Drivers
Total quality management (TQM) Continuous process improvement (CPI) Globalization of the economy Information technology problems and opportunities Year 2000 problem (Y2K) Euro currency directive Enterprise resource planning (ERP) Electronic commerce (EC or E-commerce) Conversion Notes Introduced legacy-driven trends such as Y2K and the Euro. Introduced new technology trends that are changing business processes and rules. Examples include ERP and E-commerce. Teaching Notes The Y2K problems should be mostly fixed by the time this edition is published, but some companies may still be working on lower-priority (nonmission-critical) applications. Also, some Y2K fixes were short-term fixes that may require a better long-term solution.

Total Quality Management
Total quality management (TQM) is a comprehensive approach to facilitating quality improvements and management within a business. Information systems quality standards: ISO 9001, Quality systems – Model for quality assurance in design/development, production, installation, and servicing. Capability Maturity Model (CMM) is a framework to assess the maturity level of an organization’s information systems development and management processes and products. It consists of five levels of maturity as measured by a set of guidelines called the key process areas. Teaching Notes Weinberg: “If builders built buildings the same way that programmers wrote programs, the first woodpecker would destroy civilization.” Many businesses are moving toward information systems quality certification based on one or both of the standards listed. The federal government has mandated that future companies that seek supply software for government agencies and contracts must be CMM Level 3 or better. Many of these businesses have elected to achieve this CMM Level 3 certification for all information and software, not just government contracted products. It is important to note that ISO 9001 and CMM seek to certify the process used to develop systems and software, not the systems and software for their own sake.

The CMM Process Management Model
The Capability Maturity Model (CMM) is a framework to assess the maturity level of an organization’s information system development and management processes and products. It consists of five levels of maturity as measured by a set of guidelines called the key process areas. Level 1—Initial: System development projects follow no prescribed process. Level 2—Repeatable: Project management processes and practices are established to track project costs, schedules, and functionality. Level 3—Defined: A standard system development process (sometimes called a “methodology”) is purchased or developed, and integrated throughout the information systems/services unit of the organization. Level 4—Managed: Measurable goals for quality and productivity are established. Level 5—Optimizing: The standardized system development process is continuously monitored and improved based on measures and data analysis established in Level 4. Teaching Notes Weinberg: “If builders built buildings the same way that programmers wrote programs, the first woodpecker would destroy civilization.” Many businesses are moving toward information systems quality certification based on one or both of the standards listed. The federal government has mandated that future companies that seek supply software for government agencies and contracts must be CMM Level 3 or better. Many of these businesses have elected to achieve this CMM Level 3 certification for all information and software, not just government contracted products. It is important to note that ISO 9001 and CMM seek to certify the process used to develop systems and software, not the systems and software for their own sake.

The CMM Process Management Model
Level 5 OPTIMIZED 4 MANAGED 3 DEFINED 2 REPEATABLE RISK COMPETITIVENESS 1 INITIAL Teaching Notes Weinberg: “If builders built buildings the same way that programmers wrote programs, the first woodpecker would destroy civilization.” Many businesses are moving toward information systems quality certification based on one or both of the standards listed. The federal government has mandated that future companies that seek supply software for government agencies and contracts must be CMM Level 3 or better. Many of these businesses have elected to achieve this CMM Level 3 certification for all information and software, not just government contracted products. It is important to note that ISO 9001 and CMM seek to certify the process used to develop systems and software, not the systems and software for their own sake.

Business Process Redesign
Business process redesign (BPR) is the study, analysis, and redesign of fundamental business processes to reduce costs and/or improve value added to the business. Usually complemented by continuous process improvement No additional notes

Continuous Process Improvement
Continuous process improvement (CPI) is the continuous monitoring of business processes to effect small but measurable improvements to cost reduction and value added. Essentially the opposite of business process redesign; however, CPI can and frequently does complement BPR. No additional notes

Legacy Systems Legacy systems are older information system applications that have become crucial to the day-to-day operation of a business and that may use technologies considered old or outdated by current standards. Can be adversely affected by technology and economic forces: Year 2000 Euro Can be replaced by alternative solutions: ERP E-Commerce No additional notes

Enterprise Resource Planning
An Enterprise resource planning (ERP) software product is a fully integrated information system that spans most basic business functions required by a major corporation. An ERP product is built around a common database shared these business functions. Examples of ERP software vendors include. Baan J. D. Edwards Oracle Peoplesoft SAP Teaching Notes ERP is dramatically changing the role of the modern systems analyst. Instead of spending effort on requirements planning and systems design, ERP redirects effort to activities such as customization, business process redesign and alignment, and system implementation. Systems analysts who work on ERP projects are almost always called systems integrators.

Electronic Commerce Electronic commerce (e-commerce or EC) involves conducting both internal and external business over the Internet, intranets, and extranets. Electronic commerce includes the buying and selling of goods and services, the transfer of funds, and the simplification of day-to-day business processes – all through digital communications. Three basic types of electronic commerce applications include: Marketing Business-to-consumer (B2C) Business-to-business (B2B) No additional notes

The Systems Analyst as a Facilitator
No additional notes

Skills Required by Systems Analysts
Working knowledge of information technology Computer programming experience and expertise General business knowledge Problem-solving skills Interpersonal communication skills Interpersonal relations skills Flexibility and adaptability Character and ethics Systems analysis and design skills No additional notes

Computer Ethics The Ten Commandments of Computer Ethics
1. Thou shalt not use a computer to harm other people. 2. Thou shalt not interfere with other people's computer work. 3. Thou shalt not snoop around in other people's computer files. 4. Thou shalt not use a computer to steal. 5. Thou shalt not use a computer to bear false witness. 6. Thou shalt not copy or use proprietary software for which you have not paid. 7. Thou shalt not use other people's computer resources without authorization or proper compensation. 8. Thou shalt not appropriate other people's intellectual output. 9. Thou shalt think about the social consequences of the program you are writing or the system you are designing. 10. Thou shalt always use a computer in ways that insure consideration and respect for your fellow human Conversion Notes This slide was brought forward from Module B of the 4th edition. Teaching Tips See the suggested readings for a book of ethics scenarios that could be introduced, tested, and analyzed as part of a lecture on computer ethics. We have always considered it important to emphasize that a person’s ethical integrity is “earned.” More significantly, if that ethical integrity is in any way compromised, it is difficult to repair the image. Source: Computer Ethics Institute

Information System Building Blocks
Conversion Notes This slide was brought forward from Module B of the 4th edition. Teaching Tips See the suggested readings for a book of ethics scenarios that could be introduced, tested, and analyzed as part of a lecture on computer ethics. We have always considered it important to emphasize that a person’s ethical integrity is “earned.” More significantly, if that ethical integrity is in any way compromised, it is difficult to repair the image. Source: Computer Ethics Institute

What are information systems, and who are the stakeholders in the information systems game? Describe the difference between data and information. Define the product called an information system, and describe the role of information technology in information systems. Differentiate between front- and back-office information systems. Describe five classes of information system applications (transaction processing, management information, decision support, expert, and office automation systems) and how they interoperate. Describe the role of information systems architecture in system development. Name six groups of stakeholders in information system development. Name three focuses for information systems. Describe four perspectives of the DATA focus for an information system. Describe four perspectives of the PROCESS focus for an information system. Describe four perspectives of the INTERFACE focus for an information system. Describe the role of a computer network as it relates to DATA, PROCESSES, and INTERFACES. No additional notes

Building Blocks of An Information System
Teaching Notes This is the capstone figure for the chapter—the complete information systems building blocks framework. Teaching Tips Emphasize that ALL building blocks are relevant to ALL information systems that the student will encounter or develop during the course of their career. Emphasize that the building blocks must be synchronized both horizontally and vertically when building information systems. Vertical synchronization ensures that each block represents fully the perspectives of the other blocks in the same column. For example, a database schema must implement the intended data requirements. Horizontal synchronization ensures that each block in a given row is consistent and complete with respect to the other blocks in that same row. For example, each table in a database schema requires application software and specifications to maintain the data stored in those tables.

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. The latter, purposeful intelligence, is crucial to the definition—People provide the purpose and the intelligence that produces true information. No additional notes

Information Systems & Technology
An information system (IS) is an arrangement of people, data, processes, communications, and information technology that interact to support and improve day-to-day operations in a business as well as support the problem-solving and decision making needs of management and users. Information technology is a contemporary term that describes the combination of computer technology (hardware and software) with telecommunications technology (data, image, and voice networks). Conversion Notes In previous editions, we tried to distinguish between “information systems” and “computer applications” (the latter being a subset of the former). This created more confusion with students than it was worth. Some books use the term “computer technology.” We prefer the more contemporary term, “information technology” as a superset of computer technology.

Front- and Back-Office Information Systems
Front-office information systems support business functions that reach out to customers (or constituents). Marketing Sales Customer management Back-office information systems support internal business operations and interact with suppliers (of materials, equipment, supplies, and services). Human resources Financial management Manufacturing Inventory control Conversion Notes This classification scheme comes from popular usage in the trade literature. Teaching Tips This terminology is not to be confused with office automation. In fact, office automation systems can be either front-office or back-office, just as with other types of information system applications.

A Federation of Information Systems
Teaching Tips This slide visually illustrates front- and back-office applications and highlights the following: Many organizations purchase their back-office systems in the form of enterprise resource planning (ERP) products such as SAP, PeopleSoft, and Oracle. The ERP industry is trying to expand into the front-office applications. It might be noted that electronic commerce and business extensions are being added to both front- and back-office applications in order to streamline interfaces to both customers and suppliers. E-commerce is being driven by the Internet (and private extranets). E-business is being enabled by intranets.

Classes of Information Systems
Transaction processing systems Management information systems Decision support systems Expert systems Office automation systems No additional notes

Transaction Processing
Transaction processing systems are information system applications that capture and process data about business transactions. Includes data maintenance, which provides for custodial updates to stored data. Business process redesign (BPR) is the study, analysis, and redesign of fundamental business (transaction) processes to reduce costs and/or improve value added to the business. No additional notes

Management Information Systems
A management information system (MIS) is an information system application that provides for management-oriented reporting. These reports are usually generated on a predetermined schedule and appear in a prearranged format. Conversion Notes In some previous editions and other textbooks, MIS is referred to as “management reporting.”

Decision Support Systems
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 (EIS). A data warehouse is a read-only, informational database that is populated with detailed, summary, and exception data and information generated by other transaction and management information systems. The data warehouse can then be accessed by end-users and managers with DSS tools that generate a virtually limitless variety of information in support of unstructured decisions. Conversion Notes Some books treat DSS and EIS as distinct; however, if definitions are closely examined, the differences are subtle – they only differ in audience. Both DSS and EIS tend to support the same decision-oriented activities and basically work the same. Data warehouse concepts are also taught in most database textbooks and courses. The design of a data warehouse differs significantly from traditional, operational databases.

Expert Systems An expert system is a programmed decision-making information system that captures and reproduces the knowledge and expertise of an expert problem solver or decision maker and then simulates the “thinking” or “actions” of that expert. Expert systems are implemented with artificial intelligence technology that captures, stores, and provides access to the reasoning of the experts. No additional notes

Office Automation Systems
Office automation (OA) systems support the wide range of business office activities that provide for improved work flow and communications between workers, regardless of whether or not those workers are located in the same office. 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 the needs of a work group. They are designed to boost the group’s productivity. No additional notes

Information Systems Applications
Teaching Tips It may be useful to walk through this diagram in class. The textbook coverage included numbered annotations that highlight portions of this diagram. Remind students that any given information system may include many instances of each of these IS application processes and databases.

Information Systems Architecture
Information systems architecture provides a unifying framework into which various people with different perspectives can organize and view the fundamental building blocks of information systems. No additional notes

Perspectives or Stakeholders
System owners pay for the system to be built and maintained. System users use the system to perform or support the work to be completed. System designers design the system to meet the users’ requirements. System builders construct, test, and deliver the system into operation. Systems analysts facilitate the development of information systems and computer applications by bridging the communications gap that exists between nontechnical system owners and users and technical system designers and builders. IT vendors and consultants sell hardware, software, and services to businesses for incorporation into their information systems. Conversion Notes For this edition, we added systems analysts and IT vendors and consultants. Each of these classes of stakeholders is described in greater detail in Chapter 1. Note that we use a consistent color for these stakeholders (throughout the chapter and textbook). Teaching Tips It is very important for students to understand that these are “roles,” not “job titles.” Any given individual can play more than one role. Any role is shared by many individuals.

Focuses for Information Systems
Data—the raw material used to create useful information. Processes—the activities (including management) that carry out the mission of the business. Interfaces—how the system interfaces with its users and other information systems. Conversion Notes We deleted the “geography” focus (column) from this edition. It still exists; however, the technology architecture and network for an organization is typically developed separate from the information system, and typically supports many information systems and communications needs. By eliminating this column in the fifth edition, we have simplified the framework for the students. The book still presumes that the network is a critical component for all contemporary information systems.

Teaching Notes This slide serves to establish the focus for the chapter. The highlighted cells are the information system building blocks that are described in detail as this chapter unfolds.

The DATA Focus Teaching Notes
This slide visually illustrates the chapter’s discussion of the DATA focus as seen by different stakeholders. Teaching Tips If your students have taken a database course, it can be useful to summarize that experience within the context of the DATA column.

The DATA Focus System owners’ perspective System users’ perspective
Business knowledge is the insight that is gained from timely, accurate, and relevant information. (Recall that information is a product of raw data.) System users’ perspective Data requirements are a representation of users’ data in terms of entities, attributes, relationships, and rules. Data requirements should be expressed in a format that is independent of the technology that can or will be used to store the data. System designers’ perspective Database schema System builders’ perspective Database management system Teaching Notes This slide places definitions and key terms relevant to the DATA focus into the context of stakeholders.

The PROCESS Focus Teaching Notes
This slide visually illustrates the chapter’s discussion of the PROCESS focus as seen by the different stakeholders. Teaching Tips Most students have some programming experience. Accordingly, it can be useful to summarize that experience within the context of the PROCESS column. Consider summarizing that experience by working bottom-to-top in the column to reinforce their perspective of the “application programs” they wrote. The programming instructor typically played the roles of system owners, users, and analysts when they wrote the programming assignments. The student typically played the roles of designer (e.g., flowcharts) and builder (e.g, logic).

The PROCESS Focus System owners’ perspective
Business functions are ongoing activities that support the business. Functions can be decomposed into other subfunctions and eventually into processes that do specific tasks. A cross-functional information system supports relevant business processes from several business functions without regard to traditional organizational boundaries such as divisions, departments, centers, and offices. Teaching Notes This slide places definitions and key terms relevant to the PROCESS focus into the context of stakeholders. Continued ...

The PROCESS Focus (continued)
System users’ perspectives Business processes are activities that respond to business events. Business processes are the “work” performed by the system. Process requirements are a representation of the users’ business processes in terms of activities, data flows, or work flow. A policy is a set of rules that govern a business process. A procedure is a step-by-step set of instructions and logic for accomplishing a business process. Teaching Notes This slide places definitions and key terms relevant to the PROCESS focus into the context of stakeholders. Continued ...

The PROCESS Focus (continued)
System designers’ perspectives An application schema is a model that communicates how selected business processes are, or will be, implemented using the software and hardware. Software specifications represent the technical design of business processes to be automated or supported by computer programs to be written by system builders. System builders’ perspectives Application programs are language-based, machine-readable representations of what a software process is supposed to do, or how a software process is supposed to accomplish its task. Prototyping is a technique for quickly building a functioning, but incomplete model of the information system using rapid application development tools. Teaching Notes This slide places definitions and key terms relevant to the PROCESS focus into the context of stakeholders.

The INTERFACE Focus Teaching Notes
This slide visually illustrates the chapter’s discussion of the INTERFACE focus as seen by the different stakeholders. Teaching Tips Many students have written programs for graphical user interfaces using languages such as Access, Visual Basic and HTML. Accordingly, it can be useful to summarize that experience within the context of the INTERFACE column. While it is conceptually and practically useful to separate INTERFACE and PROCESS, it should be noted that many of today’s contemporary application development environments (ADEs) such as Visual Basic effectively integrate the technology used to construct both the user interface and the application logic. Some students find this confusing. Interestingly, the emphasis on Web-based applications is truly separating the concerns. For example, the interface elements of a Web are written in HTML while the application logic is written in C++ or Java.

The INTERFACE Focus System owners’ perspective
System users’ perspectives Interface requirements are a representation of the users’ inputs and outputs. System designers’ perspective User dialogues describe how the user moves from window-to-window, interacting with the application programs to perform useful work. System builders’ perspective Middleware is a layer of utility software that sits in between application software and systems software to transparently integrate differing technologies so that they can interoperate. Teaching Notes This slide places definitions and key terms relevant to the INTERFACE focus into the context of stakeholders.

Teaching Notes This is the capstone figure for the chapter—the complete information systems building blocks framework. Teaching Tips Emphasize that ALL building blocks are relevant to ALL information systems that the student will encounter or develop during the course of their career. Emphasize that the building blocks must be synchronized both horizontally and vertically when building information systems. Vertical synchronization ensures that each block represents fully the perspectives of the other blocks in the same column. For example, a database schema must implement the intended data requirements. Horizontal synchronization ensures that each block in a given row is consistent and complete with respect to the other blocks in that same row. For example, each table in a database schema requires application software and specifications to maintain the data stored in those tables.

The Role of the Network in IS
Conversion Notes This slide illustrates the classic model of separating and partitioning the layers of an information system application across a network. This is called a distributed computing architecture and it can be implemented using either client/server or Internet/intranet technology, or a combination of both.

A COMMUNICATIONS Focus in IS
Conversion Notes While we deleted the GEOGRAPHY column that was included in our framework in the fourth edition, we did not want to ignore it. Today’s information systems are built on top of constantly evolving networks. This slide was adapted from the margin art to illustrate that the framework works equally well for network analysis and design. We acknowledge that a more complicated and well-accepted framework exists in the form of the OSI model. That is yet another reason we chosen to deemphasize this column in our fifth edition.

面向对象系统分析与设计 Object-Oriented Systems Analysis and Design

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