Information systems
CHAPTER 1: ANALYZING THE INFORMATION SYSTEM REQUIREMENTS FOR BUSINESS PROCESSES .. 2
CONTEXT ................................................................................................................................................. 2
Information systems development ............................................................................................ 2
Business process management (BPM) ...................................................................................... 3
CONCEPTS ............................................................................................................................................... 5
Business process (functional perspective) ................................................................................. 5
Business process model.......................................................................................................... 6
TECHNIQUE (BPMN PROCESS DIAGRAMS) (CONTROL-FLOW PERSPECTIVE) ........................................................... 7
DATA (OBJECT) PERSPECTIVE ........................................................................................................................ 9
RESOURCE (ORGANIZATIONAL) PERSPECTIVE ................................................................................................. 10
ADVANCED PROCESS MODELING ................................................................................................................. 12
Process decomposition ..........................................................................................................12
Process model reuse .............................................................................................................12
Handling events (zie slides) .....................................................................................................12
Handling exceptions ..............................................................................................................13
DERIVING INFORMATION SYSTEM REQUIREMENTS ............................................................................................ 14
CHAPTER 2: DESIGNING THE CONCEPTUAL MODEL OF THE INFORMATION SYSTEM .......................15
CONTEXT ............................................................................................................................................... 15
ENTITY RELATIONSHIP (ER) MODEL.............................................................................................................. 15
ENHANCED ENTITY RELATIONSHIP (EER) MODEL ........................................................................................... 17
UNIFIED MODELING LANGUAGE (UML) CLASS DIAGRAM ................................................................................. 19
CHAPTER 3: DESIGNING & IMPLEMENTING THE INFORMATION SYSTEM .........................................21
CONTEXT ............................................................................................................................................... 21
RELATIONAL MODEL ................................................................................................................................. 21
MAPPING A CONCEPTUAL MODEL ACCORDING TO THE ER MODEL TO A LOGICAL DATA MODEL ACCORDING TO THE
RELATIONAL MODEL ................................................................................................................................. 24
Mapping entity types ..............................................................................................................24
Mapping relationship types (zie slides) .....................................................................................24
Mapping multivalued attribute types ........................................................................................25
Mapping weak entity types ......................................................................................................25
TRANSLATING THE ABSTRACTIONS OF THE EER MODEL TO THE RELATIONAL MODEL ............................................... 25
Mapping an EER specialization ................................................................................................25
Mapping an EER categorization ................................................................................................26
Mapping an EER aggregation ...................................................................................................26
CONTEXT IMPLEMENTING .......................................................................................................................... 26
STRUCTURED QUERY LANGUAGE (SQL) ....................................................................................................... 26
SQL – DATA DEFINITION LANGUAGE (SQL–DDL) .......................................................................................... 27
CHAPTER 4: USING THE INFORMATION SYSTEM ............................................................................28
SQL AS DATA MANIPULATION LANGUAGE (DML) ........................................................................................... 28
SQL AS DATA QUERY LANGUAGE (DQL) ...................................................................................................... 28
SQL VIEWS ............................................................................................................................................ 29
1
,CHAPTER 1: ANALYZING THE INFORMATION SYSTEM REQUIREMENTS FOR BUSINESS PROCESSES
Context
Information systems development
Different approaches • Most important ones → waterfall
approach, structured information
system development & agile
information system development
• Most follow same sequence of
stages
Circular • Stages are in particular order
• Repeated in cyclical way
Stages • System analysis
➢ What should system do? → system requirements
➢ Understand functionalities system has to offer, what objectives to achieve
• System design
➢ Thinking about how system should do this
➢ Which information & communication technologies & technology
components
➢ Just a plan that details what is needed (like architecture of house) → no
actual construction
➢ What components? how should they work together? Interactions?
• System implementation
➢ Plan is realized
➢ Building of system according to plan → real coding, writing software code…
➢ Test whether it satisfies requirements
➔ In practice → 5% of effort is really coding ⟹ testing much more effort
• System use & maintenance
➢ System is delivered
➢ While being used → maintained
➔ Maybe defects or bugs missed during testing ⟹ fixing defects
➔ New requirements, new information needed ⟹ continuously
continues to meet requirements
After couple of years • Maintenance very expensive → requirements have changed so much
• Replacement of system, completely new version or integration into another
system
• New cycle starts
Why analysis in different • Requires different way of thinking → in terms of problem domain
color • Make sure all requirements are covered, are correct, accurate, consistent &
don’t contradict each other
• Business people → know problem domain → business processes
Solution space • Shift in mindset
• Thinking about how to address requirements
• IT people
➢ But input of business people still important → want to make sure systems
addresses needs
Why is this shift important • If system development fails → people shift too early from analysis to design
• Not think about solutions too soon if we don’t know problem well
2
, Types of requirements • High level → very general
requirements
• Low level → very detailed
requirements
System objectives • Business requirements
• What are the objectives that we want to reach, achieve, satisfy…?
System functions • How can we reach objectives? What functionality must system provide?
• System requirements
• Eg. check store availability automatically (without person that needs to go to
warehouse…)
Information needs • What information do we need to perform these functions?
• Data processing requirements
➢ Because information is what you get when you process data
➢ Data = raw facts, numbers… → no meaning or use
➢ By processing it → something meaningful & useful = information
• Eg. answer to question: do we have products in stock?
Data needs • What data must be processed to answer question
• Data storage requirements → you want to store data
• Eg. data about which products, quantities, stock levels…
Business process management (BPM)
What is it? • Operational managerial approach
• Main goal → make processes better, more efficient…
• A body of methods, techniques & tools to discover, analyze, redesign, execute
& monitor business processes
➢ Discover = understanding what process is about (by modeling)
➢ Analyzing = based on model → finding weak points
➢ Redesign = what can we do about weaknesses
➢ Monitor → during execution → measure performance
How will we do it? • Process automation → use IT based systems
➢ Essential component → make process execution more efficient
➢ Also monitor
• Process governance, innovation, analytics, change management..
➢ Change must be managed (it might take a while)
➢ Convince them about your changes
When is sales order • Timely product delivery
fulfilment efficient • Low costs
• No mistakes
• Satisfying customer needs
4 dimensions • Quality
• Cost
• Time
• Flexibility
3
CHAPTER 1: ANALYZING THE INFORMATION SYSTEM REQUIREMENTS FOR BUSINESS PROCESSES .. 2
CONTEXT ................................................................................................................................................. 2
Information systems development ............................................................................................ 2
Business process management (BPM) ...................................................................................... 3
CONCEPTS ............................................................................................................................................... 5
Business process (functional perspective) ................................................................................. 5
Business process model.......................................................................................................... 6
TECHNIQUE (BPMN PROCESS DIAGRAMS) (CONTROL-FLOW PERSPECTIVE) ........................................................... 7
DATA (OBJECT) PERSPECTIVE ........................................................................................................................ 9
RESOURCE (ORGANIZATIONAL) PERSPECTIVE ................................................................................................. 10
ADVANCED PROCESS MODELING ................................................................................................................. 12
Process decomposition ..........................................................................................................12
Process model reuse .............................................................................................................12
Handling events (zie slides) .....................................................................................................12
Handling exceptions ..............................................................................................................13
DERIVING INFORMATION SYSTEM REQUIREMENTS ............................................................................................ 14
CHAPTER 2: DESIGNING THE CONCEPTUAL MODEL OF THE INFORMATION SYSTEM .......................15
CONTEXT ............................................................................................................................................... 15
ENTITY RELATIONSHIP (ER) MODEL.............................................................................................................. 15
ENHANCED ENTITY RELATIONSHIP (EER) MODEL ........................................................................................... 17
UNIFIED MODELING LANGUAGE (UML) CLASS DIAGRAM ................................................................................. 19
CHAPTER 3: DESIGNING & IMPLEMENTING THE INFORMATION SYSTEM .........................................21
CONTEXT ............................................................................................................................................... 21
RELATIONAL MODEL ................................................................................................................................. 21
MAPPING A CONCEPTUAL MODEL ACCORDING TO THE ER MODEL TO A LOGICAL DATA MODEL ACCORDING TO THE
RELATIONAL MODEL ................................................................................................................................. 24
Mapping entity types ..............................................................................................................24
Mapping relationship types (zie slides) .....................................................................................24
Mapping multivalued attribute types ........................................................................................25
Mapping weak entity types ......................................................................................................25
TRANSLATING THE ABSTRACTIONS OF THE EER MODEL TO THE RELATIONAL MODEL ............................................... 25
Mapping an EER specialization ................................................................................................25
Mapping an EER categorization ................................................................................................26
Mapping an EER aggregation ...................................................................................................26
CONTEXT IMPLEMENTING .......................................................................................................................... 26
STRUCTURED QUERY LANGUAGE (SQL) ....................................................................................................... 26
SQL – DATA DEFINITION LANGUAGE (SQL–DDL) .......................................................................................... 27
CHAPTER 4: USING THE INFORMATION SYSTEM ............................................................................28
SQL AS DATA MANIPULATION LANGUAGE (DML) ........................................................................................... 28
SQL AS DATA QUERY LANGUAGE (DQL) ...................................................................................................... 28
SQL VIEWS ............................................................................................................................................ 29
1
,CHAPTER 1: ANALYZING THE INFORMATION SYSTEM REQUIREMENTS FOR BUSINESS PROCESSES
Context
Information systems development
Different approaches • Most important ones → waterfall
approach, structured information
system development & agile
information system development
• Most follow same sequence of
stages
Circular • Stages are in particular order
• Repeated in cyclical way
Stages • System analysis
➢ What should system do? → system requirements
➢ Understand functionalities system has to offer, what objectives to achieve
• System design
➢ Thinking about how system should do this
➢ Which information & communication technologies & technology
components
➢ Just a plan that details what is needed (like architecture of house) → no
actual construction
➢ What components? how should they work together? Interactions?
• System implementation
➢ Plan is realized
➢ Building of system according to plan → real coding, writing software code…
➢ Test whether it satisfies requirements
➔ In practice → 5% of effort is really coding ⟹ testing much more effort
• System use & maintenance
➢ System is delivered
➢ While being used → maintained
➔ Maybe defects or bugs missed during testing ⟹ fixing defects
➔ New requirements, new information needed ⟹ continuously
continues to meet requirements
After couple of years • Maintenance very expensive → requirements have changed so much
• Replacement of system, completely new version or integration into another
system
• New cycle starts
Why analysis in different • Requires different way of thinking → in terms of problem domain
color • Make sure all requirements are covered, are correct, accurate, consistent &
don’t contradict each other
• Business people → know problem domain → business processes
Solution space • Shift in mindset
• Thinking about how to address requirements
• IT people
➢ But input of business people still important → want to make sure systems
addresses needs
Why is this shift important • If system development fails → people shift too early from analysis to design
• Not think about solutions too soon if we don’t know problem well
2
, Types of requirements • High level → very general
requirements
• Low level → very detailed
requirements
System objectives • Business requirements
• What are the objectives that we want to reach, achieve, satisfy…?
System functions • How can we reach objectives? What functionality must system provide?
• System requirements
• Eg. check store availability automatically (without person that needs to go to
warehouse…)
Information needs • What information do we need to perform these functions?
• Data processing requirements
➢ Because information is what you get when you process data
➢ Data = raw facts, numbers… → no meaning or use
➢ By processing it → something meaningful & useful = information
• Eg. answer to question: do we have products in stock?
Data needs • What data must be processed to answer question
• Data storage requirements → you want to store data
• Eg. data about which products, quantities, stock levels…
Business process management (BPM)
What is it? • Operational managerial approach
• Main goal → make processes better, more efficient…
• A body of methods, techniques & tools to discover, analyze, redesign, execute
& monitor business processes
➢ Discover = understanding what process is about (by modeling)
➢ Analyzing = based on model → finding weak points
➢ Redesign = what can we do about weaknesses
➢ Monitor → during execution → measure performance
How will we do it? • Process automation → use IT based systems
➢ Essential component → make process execution more efficient
➢ Also monitor
• Process governance, innovation, analytics, change management..
➢ Change must be managed (it might take a while)
➢ Convince them about your changes
When is sales order • Timely product delivery
fulfilment efficient • Low costs
• No mistakes
• Satisfying customer needs
4 dimensions • Quality
• Cost
• Time
• Flexibility
3
