Exam summary BIS

1. Goal of this course
I. What is the main purpose of this course?
To provide the studens some important concepts and tools of business information
technology for good communication between management and computer scientists
o A few facts:
 Infromation technology has become very important nowadays, but many projects
fail because of:
▫ Shortages or even absence of agreements
▫ Wrong explanation or misrepresentation
▫ …
 Why is the knowledge of IT important for a company, organization and its
management team?
▫ Good communication
▫ Efficiency
▫ …
 52% of the investments are related to IT
 Return on IT versus IT envestment paradox: high investments in IT do not always
mean a higher productivity
 80-90% of IT projects fail
o Alginment definition
"applying IT in an appropriate and timely way and in harmony with business strategies,
goals and needs"
o Weakness – risk:
 Smooth progress depends on the appropriate functioning of IT
o What if the IT is down?
Problems with:
 Web-shop
 Management of orders
 Payments
 Customer service
 …
II. Some introductory concepts
IT is increasingly present in our modern society
Input -> computer -> output
o Hardware:
 Input
 Output
 Computer
▫ Memory: RAM/ROM
▫ CPU (Central Processing Unit)
o Software
 Sequence of orders formulated by programs
 Conversion into machine language
Machine language: the set of symbolic intstruction codes usually in binary form
that is used to represent operations and data in a machine
 Modules
▫ Reuse
▫ Less complex
▫ Splitting into sub-problems
▫ Error module easier to find


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, ▫ Collaboration with several people
 Besides programs, software can also be DATA
o Database
 Organized collection of data stored in a computer
 Relational database
o Network
 Multiple comuters communicate and exchange data
 Types: PAN, LAN, MAN, WAN
 Protocols:
▫ TCP: Transmission COntrol Protocol
▫ IP: Internet Protocol
o Servers
 Computer only for calculation and storage
o Internet
 Teh biggest internetwork
 In OECD penetration rate of +/- 83%
o Computer architecture
 Fundamental organization of the computer system
▫ Phase 1: mainframe
▫ Phase 2: PC & client server
▫ Phase 3: browser/cloud
o Processes
 A business process is a sequence of steps/actions with the aim of generating a
product or a service.
 Start in '90: need for operation between various actors/departments within an
organization
o Information System
 The combination of IT hardware, software, processes and people who use it
2. Algorithms
I. When solving a problem using the computer it is strongly recomended to go through the
following steps:
o Problem definition
The problem will be fully and accurately defined: from which initial situation is started,
which results must be obtained and what is the link between both.
o Solution strategy
This is the choice of a solution method and of the data repersentation:
 Trying to divide the problem into smaller sub-problmes
 Agreeing what will happen in each sub-problem
o Representation of the algorithm
 Examples: flow chart, nassi-schneidermann-diagram, pseudo code,...
o Programming
 When encoding, the fully elaborated algorithm translated into the selected
programming language.
 For example: ADA, Basic, C++, Cocol, Delphi, Fortran, Java, Javascript, Pascal,
Python, R, Visual Basic,...
o Compiling
 To detected eventual suntax errors
 Translation into machine language
 Compiler versus interpreter
o Testing
 Results must also be logically correct

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,  Compare with results obtained in a different way
 Test all different cases
o Documenting
 All information that will help third parties to understand, modify, improve or
complete the program
o Maintenance
 After a while the program eventually has to be updated
 Report changes in the documantation
II. What is an algorithm?
o Today, algorithms are used in many applications such as:
 The functioning of computers
 Cryptofraphy
 Information routing
 Planning and optimal use of resources
 Image processing
 Tekst processing
 Bio-computing
 …
o Definition:
An algorithm is a method to solve a problem:
 A sequence of actions/commands/rules
 Starting from a given initial situation
 Leading to a certain goal
 Within a finite time
The commands must be understood in an unambiguous way
III. Algorithm representations
o An algorithm can be presented by:
 A flow chart
A flow chart is a scheme with basic figures instructions are included in the figures
and the figures are connected by lines/arrows
 A nassi-schneidermann-diagram
 Pseudo code
o Overvieuw algorithm representatations
 Sequence
 Selection
▫ If then
▫ If then else
▫ Case
 Iteration
▫ While
▫ Repeat
▫ For
3. Programming
I. Python in a nutshell
a. A few facts
 Programming language
 Designed in the early 90's vy Fuido van Rossum
 Affiliated with the Center for Mathematics in Amsterdam
 BASIC based language based on ABC
 Supported by volunteers on the internet
 The Python development is led by the Python SOftware Foundation

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,  Python is free software
b. Characteristics
 Readable code
 Structure through indentation
 Statements ended by the end of the line
 Variables do not receive a type declaration
 Duck-typing:
▫ Type of a variable and the type of an argument does not have to be defined
▫ In the case of compilation, there is no type control
▫ In case of mismatch, an error message will folloz
 EAFP (Easier to Ask for Forgiveness Than Permission)
▫ A function or method is started without first checking wether it is working
properly
 Execution
▫ Written in one or more tekst files with the extension .py
 Interpreter:
▫ Compiles to an itermediate form, called bytecode
▫ The byte code is independent of the operating system
▫ The next step is to change the bytecode into machine language
▫ Slower than programs written in a language with a compiler
 Garbage collection
▫ Python memory space is automatically reserved for new variables
▫ Released again if there are no more references to those variables
 Stnadalone executables
 Libraries
c. Python single predefined types:
 Integer: whole numbers
 Float: with numbers after the comma
 String: symbol
 Boolean: true/false
d. Basic instructions
Traditional programming concepts:
 Operators
= assignment
 Arithmetic operatiors
▫ + addition
▫ - substraction
▫ * multiplication
▫ / division
▫ //floor division
▫ % modulo
▫ ** power
 Functions input & print
▫ Print: to write something
▫ Input: to enter values in a variable
II. Programming
a. Generation programming languages
 First-generation programming language
▫ Machine level languages
▫ No translator to compile or assemble


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