IT-Modeling
Information systems
What?
System -> Separate components that effect, interact & work together to realize a
common set of objectives /goals
Goals?
Turning data into information (aka data with utility)
Main goals :
increase effectiveness and efficienty
get a competitive advantage
Development -> Model
What?
Simplified representation of reality
-> description of a system written in notation (UML)
Sorts of models :
Physical model : prototype
Graphical model
Mathematical model : set of equations or formulas (ex. linear regression
model)
Risks?
due to simplifications not entirely correct
Risk of information system development : expensive, dependent
Why?
Analysis & decision making
Communication
Planning (ex. electricity planning)
Simulation
Optimizing
Models are a tool, they only have use if they help us realize our end goal.
How?
System Development life cycle (SDLC)
5 Phases
, System Development life cycle (SDLC)
5 Phases
Aims :
high quality systems
meet or exceed customers expectations
based on customer requirements
staying within each time phase & budget estimates
Phase 1 : system investigation
Identification
What do we need?
What is our problem?
Do we have business opportunities?
How can IS help us realize our business priorities?
Feasibility
Feasibility study -> determines information needs, recource requirements &
feasibility of the project
categories :
Operational : Support business priorities?
Economic : Cost-benefits analysis
Technical : Do we have the scales? Outscourcing?
Human factors : accepted by management, employees,...?
Legal : Does system comply to regulations? Laws?
Phase 2 : System analysis
Analyse requirements & capibilities
Develop conceptual models
Conceptual data model
describes the structure of data and relationships between different data
elements -> It defines the data entities, attributes, and relationships, used to
design and implement databases and other data storage systems
What data should be stored & how it should be organised
Conceptual process model
describes the workflow and activities to make up a process or system ->
outlines the steps and tasks involved, inputs & outputs, actors involved in the
process
How it should be done
Information systems
What?
System -> Separate components that effect, interact & work together to realize a
common set of objectives /goals
Goals?
Turning data into information (aka data with utility)
Main goals :
increase effectiveness and efficienty
get a competitive advantage
Development -> Model
What?
Simplified representation of reality
-> description of a system written in notation (UML)
Sorts of models :
Physical model : prototype
Graphical model
Mathematical model : set of equations or formulas (ex. linear regression
model)
Risks?
due to simplifications not entirely correct
Risk of information system development : expensive, dependent
Why?
Analysis & decision making
Communication
Planning (ex. electricity planning)
Simulation
Optimizing
Models are a tool, they only have use if they help us realize our end goal.
How?
System Development life cycle (SDLC)
5 Phases
, System Development life cycle (SDLC)
5 Phases
Aims :
high quality systems
meet or exceed customers expectations
based on customer requirements
staying within each time phase & budget estimates
Phase 1 : system investigation
Identification
What do we need?
What is our problem?
Do we have business opportunities?
How can IS help us realize our business priorities?
Feasibility
Feasibility study -> determines information needs, recource requirements &
feasibility of the project
categories :
Operational : Support business priorities?
Economic : Cost-benefits analysis
Technical : Do we have the scales? Outscourcing?
Human factors : accepted by management, employees,...?
Legal : Does system comply to regulations? Laws?
Phase 2 : System analysis
Analyse requirements & capibilities
Develop conceptual models
Conceptual data model
describes the structure of data and relationships between different data
elements -> It defines the data entities, attributes, and relationships, used to
design and implement databases and other data storage systems
What data should be stored & how it should be organised
Conceptual process model
describes the workflow and activities to make up a process or system ->
outlines the steps and tasks involved, inputs & outputs, actors involved in the
process
How it should be done
