Ch. 1: Structure and Organization of Information Systems

Question 1

What is a bit?

Answer 1

This is the smallest possible unit of information. One bit corresponds to the amount of information in an answer to a question with only two possibilities.

Question 2

Please give an example of the physical or electrotechnical replication of 1 and 0.

Answer 2

Possible examples are – among others:
- Lamp: Off/On
- Switch position: Off/On
- Change of elevation and depression on CD, DVD, or Blu-Ray-Disc
- Magnetic state of magnetizable material

Question 3

Please name and explain the Boolean operations.

Answer 3

• The Boolean operation “AND” is a two-digit operation. It evaluates two Boolean values X and Y to 1 if both values are 1. Otherwise, AND evaluates to 0.
• The Boolean operation “OR” is also a two-digit operation. It evaluates two values X and Y to be 1 if at least one of the values is 1.
• The operation “NOT” has one digit. It simply negates the value X. The value 1 is evaluated as 0, the value 0 as 1.

Question 4

What does the Boolean operator OR evaluate to?

Answer 4

To two values, x and y, to 1, if any value is 1.

Question 5

Please describe how individual digits and letters can be represented as a sequence of 0 and 1.

Answer 5

There are defined mappings and standards for this, for example, ASCII or UTF-8. In UTF-8, the sequence 01010011 represents the letter “S.” In order to save in binary letters and digits, you only have to look up the UTF-8 table.

Question 6

What was the novel idea of von Neumann architecture at the time it was invented?

Answer 6

Von Neumann developed the idea of storing the computer programs together with the data to be processed in a shared memory (the main memory) of the computer. Since the programs are also in a changeable memory, the rules and instructions on how the data are processed can also be adapted without having to exchange the hardware components of the computer system. Von Neumann thus constructed a computing system that, unlike what was common for computing systems at the time, was not intended to solve a specific problem.

Question 7

Please name the units of the von Neumann architecture.

Answer 7

• Memory
• Control unit (as part of the CPU)
• Arithmetic logical unit (as part of the CPU)
• Input/output units
• Bus system

Question 8

What does the acronym ALU stand for?

Answer 8

Arithmetical logical unit.

Question 9

Please differentiate the tasks of the control unit and the arithmetic unit.

Answer 9

The control unit is the coordinator in the CPU. First of all, it is responsible for loading the commands to be executed in a program from the memory into the CPU in the correct order and for interpreting them. In addition, the source and target of the data to be processed must be interconnected with the arithmetic logical unit, and the arithmetic logical unit must be informed which calculation it should carry out with the data.
The arithmetic logical unit is the only component of the computer in which calculations are carried out. The arithmetic logical unit has a number of executable arithmetic and logical functions. All binary operations of computer systems are carried out in that unit.

Question 10

What do the memory, input/output units and bus system do?

Answer 10

• The memory of a von Neumann computer is used to store binary coded data and programs; there is only one type of memory. The available memory is divided into small areas that are numbered consecutively with a unique address. Data that are stored in a memory cell can be called up via their address. When accessing memory, the memory area in the storage medium is located and then read out or changed.
• The I/O units are the interface between the system and its surrounding environment. They are responsible for the flow of incoming and outgoing data and programs.
• The bus is a data transmission system used by all units for communication. In a von Neumann computer, all data are transferred over the bus.

Question 11

What is a distributed system?

Answer 11

This is a software system that can only be used in conjunction with several computers connected via a communication network.

Question 12

Please name the typical elements and their tasks in distributed systems.

Answer 12

Server: refers to computers that offer functions that can be called up by other computers via a communication network.
Client: computers that use the services offered by servers
Communication network: network for communication between computer systems. It routes messages from one computer to another.
Message: information sent between computers via the communication network.

Question 13

Please name two practical examples of the interaction between client and server.

Answer 13

• The browser (client) is used to order something from an online shop (server).
• The laptop (client) should print out a document via a network printer (server).
• The mobile phone (client) retrieves the current weather data from a weather service (server).

Question 14

What is a protocol in conceptual model for communication?

Answer 14

A set of conventions that govern the interaction of processes, devices, and other components within a system is a protocol, such as TCP/IP or OSI.

Question 15

Please name the seven layers of the OSI reference model.

Answer 15

Application, presentation, session, transport, network, link, and physical layer.

Question 16

The functions (protocols) of which layer in the ISO OSI and TCP/IP reference model ensure that all data packets that have been sent arrive at the recipient?

Answer 16

Transport layer.

Question 17

Describe at least 4 layers in the OSI or TCP/IP protocol.

Answer 17

• Application layer: The functions (protocols) of the application layer in both reference models contain application-specific definitions for the structure and exchange of messages (HTTP, SMTP, …).
• Presentation and session layer: They are responsible for tasks such as character encoding, data compression, and encryption and decryption of information. The session layer enables sessions to be set up between remote computers.
• Transport layer: messages from the higher layers are divided into smaller units and passed on to the network or internet layer. In addition, the protocols use appropriate security functions in the transport layer to ensure that all data packets that have been sent arrive at the recipient.
• Network layer / internet layer: The network layer of the OSI model is responsible for the operation of the communication network. It takes care of the selection of the route through the network that a data packet travels, from the sender to the recipient. The internet layer in the TCP/IP reference model is very similar to the network layer in the OSI reference model.
• (Data) link layer: it ensures that the data are transferred completely and without errors from one computer to the next in the route.
• Physical layer: According to the OSI model, the bit transmission layer is responsible for transmitting the binary coded digital data packets over the physical communication channel. This means mapping the bit sequences to be transported to the properties (electricity, light, and radio waves), transmitting them, and converting them back into bit sequences.

Question 18

Please explain the concept of an enterprise information system.

Answer 18

We use the term enterprise information system to refer to commercially used software systems and their system context. With the restriction to commercial use, the software systems that are used directly or indirectly to achieve business goals are placed in the foreground. The system context contains interfaces to the users of the system and technical interfaces to other systems.

Question 19

Please name four classes of information systems.

Answer 19

Communication systems, cross-sectional systems, functional area information systems, and management information systems.

Question 20

What is a communication system in enterprise information systems?

Answer 20

Communication systems support interpersonal communication using email, video telephone, chat, or social networks. Microsoft Outlook, Zoom, and Slack are typical examples of this type of system.

Question 21

What is a cross-sectional system in enterprise information systems?

Answer 21

All systems that are not communication systems but are also used as standard software are referred to as cross-sectional systems. Typical examples of cross-sectional systems are word processing, spreadsheets, and presentation systems, such as Word, Keynote, PowerPoint, or LibreOffice.

Question 22

What does the acronym FAIS stand for?

Answer 22

Functional area information systems.

Question 23

How do FAIS differ from management information systems?

Answer 23

FAIS specifically support business processes and activities in organizations. Of all system classes, FAIS are most strongly customized to the value-adding and supporting business processes of organizations. Enterprise Resource Planning (ERP) systems, such as those produced by SAP, are also mainly to be counted among the FAIS.
Management information systems are used to support planning and decision-making processes. Typical management information systems are data warehouse and business intelligence solutions. Cleaned and condensed data from the FAIS on procedures, processes, and business transactions are stored in management information systems.

Question 24

What is a management information system in enterprise information systems?

Answer 24

Management information systems are used to support planning and decision-making processes. Typical management information systems are data warehouse and business intelligence solutions. Purposefully cleaned and compressed data from the FAIS on procedures, processes, and business transactions are stored in these systems. These data can be summarized in the systems and prepared for the respective target group. In contrast to FAIS, the focus is not on business processes, but on data that are collected when the business processes are processed.