Information Systems vs Application Systems
- Application System = Software + Hardware System (includes various technological concepts and elements on the software and hardware level)
- Information System: Application System + Non technological elements (people & procedures)
Hardware
= all physical components of an application system (e.g. computers, servers, terminals,..)
Input Processing/ Storage-Output (IPO+S Model)
= most basic structure for describing a process
-> this is how a computer program and a single algorithm in a programming language work
Von Neumann Architecture
- Memory (RAM - Random Access Memory)
- buffers data for execution and the resulting data output
- only maintains data when powered (volatil storage)
- Processor (CPU - Central Processing Unit)
- Control Unit = accesses and decodes instructions stored in memory, controls the sequence of execution of the instructions
- Arithmetic Logic Unit = receives decoded instructions from CU and executes the instructions
Software (Definition & Characteristics (7)
Software = consists of clearly defined instructions that, upon execution, instruct hardware to perform the task for which it is designed
- immaterial product -> no physical restrictions for changes at any time
- no wear out -> no sphere parts needed
- aging through alternative technology
- easy to replicate
- difficult to quantify
- no logistics (shipping/storage) or production needed
Types of Software (Types (2) & Classification)
- System Software = controls & manages access to hardware (Windows 7, Linux,..)
- Application Software = must work through the system software; end-users primarily use application software (Open Office, SAP ERP,..)
Classification: Difference between
- Product Software (“buy” decision)
- Tailor Made Software (“make” decision)
Traditional Applications (Characteristics (4) & Tasks (3))
- run on a single system
- installed on a computer and accessible only on this computer -> data is stored on this computer and can be shared (e-mail, Dropbox, Google Drive,..)
- application provides a user interface => makes it easy to use
- application runs on the computer’s processing power
Need to do the following job:
- Interact with user (user interface)
- perform tasks (processing)
- store data
Distributed Applications (Advantage to Traditional Applications)
Solution to traditional application -> three tasks (user interface, processing, data) can be split up among two or more devices
=> the responsibilities of the application have been distributed among multiple, geographically distant computers.
Server (Components (2))
- Hardware
- a normal computer
- designed for reliability and to serve large numbers of requests
- runs server software
- Software
- computer program
- provides functionality as a service
- clients sends request -> server processes request and replies
- one physical server can run multiple server programs
Multi-Tier Architecture
= an architecture in which presentation, application processing and data management functions are separated into User Interface Tier (client), Application Tier & Database Tier
Advantages of Multi-Tier Architecture
- Security = different security options for different tiers
- Scalability = upscale the data tier without touching the presentation layer
- Maintainability = system admins can maintain tiers separately
- Easily Enhanced = each layer can be enhanced without touching the remaining tiers
Channels (Definition, Ideal, Types (3))
= customer’s contact point or medium through which the company and the customer interact. Customers expect companies to have more than one channel!
In the ideal company:
- customers can use different channels at the same time
- customers expect a seamless interaction between channels
- every channels provides the same information and data
- all channels are fully integrated
Types of channels:
- Multi-Channel = company access through multiple channels, NOT integrated
- Cross-Channel = company access through multiple channels, PARTIALLY integrated
- Omni-Channel = company access through multiple channels, FULLY integrated
Channel Integration (Customers Expectancy)
Customers expect consistent, uniform, and integrated services and experience, regardless of the channel they use. They are willing to move seamlessly between channels (traditional store, online & mobile) depending on their preference, their current situation, the time of day, or the product category.
Network
= linkage of different devices (terminals, files servers, mainframes,..) which enables communication between those devices
-> needed to connect multiple/several computers => all computers are connected to the same physical medium (either cable or wireless)
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1. Introduction to Information Systems5
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2. Technology Foundations14
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3. Introduction to Databases21
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4. IT IN Organizations28
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5. Requirements Engineering22
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6. Design & Development of IS19
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7. Information Systems & Data Semantics9
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8. Process Mining11
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9. IS Adoption and Use20
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10. Machine Learning19
