Chapter 2
An Introduction to System Concepts and Systems Architecture
2.1. (BL 2) There are a number of possibilities. Here are two: a functional representation, in which the components include the digestive system, circulatory system, skeletal system, nervous system, muscular system, respiratory system, reproductive system, etc. The digestive system can be broken further into the stomach, intestines, liver, bladder, rectum, and so on. Another system representation would be physical. System components would consist of head, arms, hands, torso, legs, and feet. Head components might include forehead, ears, eyes, nose, mouth, chin, and so on. There are many other possible models that students might come up with.
2.2. The answer to this question will be different for every student, depending on the organization that they select.
2.3. (BL 2-) The parts of the book are divided into chapters. Chapters are comprised of sections, including numbered sections, plus summary and review, "for further reading," key concepts and terms, reading review questions, and exercises sections. Many sections are subdivided into subsections. Beneath the sections or subsections are paragraphs, and then sentences, words, and alphanumeric characters.
2.4. (BL 2) The key to system analysis is the ability to divide a system into smaller pieces that can be analyzed more easily and somewhat independently. Because the system is made up of components and links it becomes possible to decompose and analyze components individually and to isolate and study the interactions between components that comprise the links. Further decomposition allows simplification of the analysis of the more complex components. Additionally, the clear delineation between a system and its environment allows analysis of the interaction and impacts between the system and the various elements of the environment.
2.5. (BL 2) The input to this system is a request for data from the database in the form of a query. The environmental element making the request is a user. The expected output from the system is the requested data. Again, the environmental element receiving the output is the user.
The processing takes place in a number of steps:
(1) Keyboard input from the user is translated by the Web browser into an HTTP request, which is sent to the Web server.
(2) The Web server interprets the user's request, creates a corresponding CGI request, and sends the CGI request to the database server.
(3) The database server processes the request to obtain the desired database results, and returns the results to the Web Server.
(4) If necessary, the Web server transforms the results into suitable HTML format and sends the HTML to the Web browser for display.
(5) The Web browser processes the HTML to display the results for the user.
2.6. (BL 2-)
2.7. (BL 2-) The cloud is an abstraction representing the end-to-end connection between two communicating computers, including all components required to implement and support the connection. These components might include computers, routers, modems, cables, transmitters, receivers, software, protocols, Wi-Fi access points,
