1. Topic 4 Basic concepts for the description of software development
Topic 4: Lecture Notes (instructions for the lecturer)
Author of the topic: Klaus Bothe (Berlin)
English version: Klaus Bothe (Berlin)
Author of the lecture notes: Klaus Bothe (Berlin), 18th Nov 2002
About the subject of this topic
This is one of the key topics of the whole course.
The question is how to describe all the SW documents which have to be produced during the whole SW development process:
- requirements documents
- design documents
- implementation documents.
There are a lot of accepted techniques applied in practice to deal with this problem: class diagrams, data flow diagrams, grammars, Petri nets ...
The key idea (included in the textbook from Balzert, Software-Technik, 1996, 2001) is to classify all the description techniques used in practice. In this way, there is a better systematics and a better overview of all these techniques for the practitioner as well as for the presentation of SE courses like this.
The contents of the whole course follows this classification presented in this topic.
To do:
To apply style guidelines, once when they are finished.
Slide 15: put Z to object oriented view?
Slide 15. Instead: ‘Source code subsystems’ -> ‘Logical-level subsystems’?
Slides that could be improved or replaced: -
Duration of the lecture:
Klaus Bothe, summer 2002: 40 minutes
Zoran Budimac, November 2002: 60 minutes (for the people from the industry)
History of changes
(with respect to previous version(s), slide numbers are from this version):
Parts of this topic use material from the textbook
H. Balzert, “Software-Technik”, Vol. 1, 2nd ed., Spektrum Akademischer Verlag, 2001

2. Basic concepts for the description of software development
Description of results of software development phases - software development documents
Definition of basic concepts for the description of software development and their classification
Basic concepts and software development phases
Classification of basic concepts according to their notation
Basic concepts and their application areas
Basic concepts and their use in analysis methods
Remark:
As opposed to other topics, this contents overview will not be repeated inside the topic slides.
The reason is that to each point often belong only a few (ore only one) slides. This would burden the presentation material by too much contents slides.

3. Description techniques of software documents
Problem: How to describe ?
customer‘s requests
specification
design
code
Remark:
The picture is a repetition of a slide of topic 3 extended by the key question to be dealt with in this topic.
customer
requirements engineer
designer
programmer
Schneider, SEUH 43, p. 123

4. Description of software documents by …
classification?
state automaton
use case diagr.
sequence diagr.
entity relation- ship diagr.
pseudo code
data flow-diagr.
Methodology:
Ask the students the implicite question from the headline.
Some predifined answers are prepared.
After that, the second question („classification“) is more a declaration of the goal of the next steps rather than a question to the students.
UML
class diagr.

5. Basic concepts of … software development Balzert vol
Basic concepts of … software development Balzert vol. 1, 2nd edition 2001
Function tree
Data-Dictio-nary 1979
Class diagram
1980/
1990
Box diagram
1973
Program flowchart
1966
Pseudo
code
Decision tables
1957
Rules
Petri Net 1962
Sequ-ence diagram
1987
State automaton 1954
Entity Relation- ship Model
1976
Data flow diagram
Use Case Diagram
Activity diagram
1997
Collabo-ration diagram
Functional View
Data-Oriented View
Object- Oriented View
Algorith- mic View
Functional
hierarchy
Business
Process
Infor- mation
Flow
Class
structures
Data
Structures
Rule- Based View
State-Oriented View
Control
If-Then
Entity types and relations
Finite
State
Automaton
Concurrent
Interaction
Scenario- Based View
Concepts and Views
Alternative Notations
Often used
Rarely used
Remark:
This is the original picture presented in Balzert‘s book from 2nd edition (2001).
It contains the proposed classification scheme: Description techniques are sorted according a three-level classification scheme.
The explanation will follow at the next slide.
Methodology:
This picture should be given to the students in paper form – because it includes the fundamental idea of succeeding topics.

6. Basic concepts: fundamental approach
Function tree
Data-Dictio-nary 1979
Class diagram
1980/
1990
Box diagram
1973
Program flowchart
1966
Pseudo
code
Decision tables
1957
Rules
Petri-Net 1962
Sequ-ence diagram
1987
State automaton 1954
Entity Relation- ship Model
1976
Data flow diagram
Use Case Diagram
Activity diagram
1997
Collabo-ration diagram
Functional View
Data-Oriented View
Object- Oriented View
Algorith- mic View
Functional
hierarchy
Business
Process
Infor- mation
Flow
Class
structures
Data
Structures
Rule- Based View
State-Oriented View
Control
If-Then
Entity types and relations
Finite
State
Automaton
Concurrent
Interaction
Scenario- Based View
Concepts and Views
Alternative Notations
Often used
Rarely used X
elementary description mechanisms
UML
classification in three levels:
Which view on the software?
basic concept
Which aspect of this view?
Which actual notational forms?
Contents:
The classification of the basic concepts is based on the following principles:
1. The classification concerns elementary description techniques (like class diagrams and collaboration diagrams) rather than comprehensive description languages including a couple of elementary techniques (like UML covering class diagrams, collaboration diagrams, and others)
2. The classification of elementary description techniques covers 3 levels:
a) Which view on the SW is being supported by the description technique?
In other words: The s a m e software can be viewed from different sides.
b) Which aspect of this view is concerned?
c) Which actual or alternative notational forms exist?
Methodology:
At this moment, all the parts of this table should not be discussed or mentioned. It should only be used as an overview of the methods and to illustrate the proposed systematics.
Nevertheless, some examples should be given, e.g.
functional view means: a software function has to be specified
data-oriented view means: data as part of the software have to specified from the structural point of view
object-oriented view means: data and functions are unified to a class unit which forms the center of this view
a view can be detailed into several aspects of the view: e. g. functional view to ...
Remarks:
1. This scheme is rather adaptable:
new or missing notations can be integrated
new views and aspects can be included
2. The notation (concept) of a programming language has not been considered. The idea of a basic concept is how to describe the software rather than how to do implementation. Thus, there are several basic concepts (esp. for the algorithmic view: pseudo code ...) for describing the code structure rather than directly for coding.

7. Basic concepts of … software development Balzert vol
Basic concepts of … software development Balzert vol. 1, 1st edition 1996
Function tree
Data-Dictio-nary 1979
Class diagram
1980/
1990
Box diagram
1973
Program flowchart
1966
Pseudo
code
Decision tables
1957
Rules
Petri Net 1962
Inter-action Diagr.
1987
State automaton 1954
Entity Relation- ship Model
1976
Data flow diagram
Functional View
Data-Oriented View
Object- Oriented View
Algorith- mic View
Functional
hierarchy
Business
Process
Infor- mation
Flow
Class
structures
Data
Structures
Rule- Based View
State-Oriented View
Control
If-Then
Entity types and relations
Finite
State
Automaton
Concurrent
Interaction
Scenario- Based View
Concepts and Views
Alternative Notations
Often used
Rarely used
Jackson Diagr. 1975
Warnier-Orr-Diagr. 1972
Syntax Diagr. 1964
development:
1996  2001
Contents:
Compared with the table from the first edition from Balzert‘s book in 1996 (this slide), we can illustrate that there is a development of basic concepts over the years – and there is no problem to adapt the scheme.
Three problem areas can be identified:
1. missing basic concepts in the table of 1996:
use case diagrams have not been so popular in 1996;
activity diagrams did not exist in 1996.
2. replaced notations:
interaction diagrams have been replaced by two different notational forms.
3. dropped notations in the table of 2001 which already have been included in 1996:
e. g. Jackson diagrams are no more widely used in practice

8. Software Development Remains a Mixture of Methods
Software development as science and as a practical activity have something in common: heterogeneity.
Contents:
Now, this well-known article from a former topic becomes obvious: This mixture of methods depends on the variety of views, aspects and notations used in software development.
Diversity of approaches in basic concepts:  different views on software products must be possible (different aspects of a software product)
Computer-Zeitung 25/96 (20. June 96)

9. Basic concepts: principles
application-independent  kind of application determines the choice of a convenient basic concept
method-independent  basic concepts can be combined to general methods (e.g. structured analysis, OOA with UML ...)
phase-independent  usable in different phases
Remark:
In the next slides, these three principles will be considered in depth.

10. Basic concepts and software development phases
ER (entity relationship
Petri net
data flow diagram
use case diag.
definition phase
state automaton
function tree
sequence diagram
collaboration diagram
design phase
DD (data dictionary)
class diagram
pseudo code
rules
decision table
Contents:
This figure illustrates that basic concepts are phase-independent: There are several basic concepts used in different phases.
Methodology:
Several (but not all) examples should be discussed.
Remark:
The proper contents of this pictures are not basic concepts but their concrete notational forms / notational representatives.
But this does not matter.
box diagram
program flow chart
implementation phase
Legend: A  B: A is used in B

11. Classification of basic concepts according to their notation
Petri nets
state
diagram
graphical ER
decision
table
data flow
diagram
use case diagr.
class
diagram
box diagram
function tree
program flow chart
verbal
sequence
diagram
collaboration
diagram
state automaton
Contents:
Basic concepts can be classified according to two aspects: formality and textual/graphical notation.
“Formal” means: there is a strong mathematical semantics (e. g. Petri net, state automaton).
Methodology:
Take some examples. In particular, it is interesting that some basic concepts appear in different forms:
Petri nets can be defined in textual (pure) mathematical form – they also can be drawn as a graphics.
The same applies to state automata and its graphical form (state diagram).
Remark:
Verbal notations have not been mentioned so far. The reason is that they cannot be connected with special views or concepts since a verbal description can be everything.
Of course, software can also be described verbally.
decision table
state automaton
(textual)
numbered
requirements
textual
pseudo code
clasification
scheme
Petri nets (textual)
text
rules DD
informal
semiformal/formalized
formal

12. Basic concepts and their application areas
complexity...
basic concepts
...of data
...of functions
...of algorithms
...of system environment
...of time-dependent behavior
...of user interface
data dictionary
ER (Entity Relationship)
(state automaton)
class diagram
use case diagram
data flow diagram
function tree
pseudo code
program flow chart
box diagram
decision table
rules
Petri nets
state automaton
activity diagram
sequence diagram
collaboration diagram
graphical specification
(Petri nets)
control structures
technical- scientific
real-time
administrative
human- computer- interaction
Contents:
The application area determines useful basic concepts.
Methodology:
Choose some examples, e. g. technical and scientific applications often have to do with complex algorithms (complex functionality).
In this case, basic concepts for the algorithmic view and of functional view are useful, and concepts for data are not so important.
legend: ( ) = limited

13. Basic concepts of … software development: enhancements Balzert vol
Basic concepts of … software development: enhancements Balzert vol. 1, 2nd edition 2001 Z
Algebraic Specifica-tion 1972
Hoare logic 1969
Structure Chart
EBNF
Gram-mars
Package Diagr
Component
Diagr.
State Chart 1987
SDL
Basic concepts:
complete?
additional forms of notations?
3 level classification
scheme flexible
Function tree
Data-Dictio-nary 1979
Class diagram
1980/
1990
Box diagram
1973
Program flowchart
1966
Pseudo
code
Decision tables
1957
Rules
Petri Net 1962
Sequ-ence diagram
1987
State automaton 1954
Entity Relation- ship Model
1976
Data flow diagram
Use Case Diagram
Activity diagram
1997
Collabo-ration diagram
Functional View
Data-Oriented View
Object- Oriented View
Algorith- mic View
Functional
hierarchy
Business
Process
Infor- mation
Flow
Class
structures
Data
Structures
Rule- Based View
State-Oriented View
Control
If-Then
Entity types and relations
Finite
State
Automaton
Concurrent
Interaction
Scenario- Based View
Contents:
This slide illustrates the flexibility of this 3-level classification:
If there are new (or forgotten) basic concepts or notational forms, there is no problem to include them.
Methodology:
The students can be asked if they know description techniques that have not been included yet.
Some of these are prepared at the top line of this picture.
The next slide shows how to deal with the new candidates.

14. Basic concepts: classification of enhancements? Z
Algebraic Specifica-tion 1972
Hoare logic 1969
Structure Chart
EBNF
Gram-mars
Package Diagr
Component
Diagr.
state chart 1987
SDL
Function tree
Data-Dictio-nary 1979
Class diagram
1980/
1990
Box diagram
1973
Program flowchart
1966
Pseudo
code
Decision tables
1957
Rules
Petri Net 1962
Sequ-ence diagram
1987
State automaton 1954
Entity Relation- ship Model
1976
Data flow diagram
Use Case Diagram
Activity diagram
1997
Collabo-ration diagram
Functional View
Data-Oriented View
Object- Oriented View
Algorith- mic View
Functional
hierarchy
Business
Process
Infor- mation
Flow
Class
structures
Data
Structures
Rule- Based View
State-Oriented View
Control
If-Then
Entity types and relations
Finite
State
Automaton
Concurrent
Interaction
Scenario- Based View
Contents:
1. The leftmost four notational forms fall into the function view (details next slides).
2. Grammers and EBNF are the more fundamental notations for the description of data structures.
3. State charts are a form of a finite state automaton.
4. SDL is a specification language for telecommunication systems which are described by a set of communicating automata. SDL will not be included in this course (at HU there is a separate course on SDL).
Remark:
Z, Hoare logic and algebraic specifications are main representatives of formal software specification languages. They are part of this course.
Structure charts are included in the topic on structured design.

15. Basic concepts: detailed classification of enhancements
Extension of views ... Z
Extension of aspects ...
Gram-mars
Box diagram
1973
Structure Chart
EBNF
Program flowchart
1966
PackageDiagr
Component diagr.
Functiontree
Use Case Diagram
1987
Data flow diagram
1966
Hoare logic
Algebraic Specifi-cation 1972
Data-Dictio-nary 1979
ER Entity Relation- ship) 1976
Class diagram
1980/
1990
Pseudo
code
Contents:
This slide details the former slide. It turns out that the general 3-level classification scheme can be maintained.
It only has to be extended by new aspects (i. e. new basic concepts). For example, Hoare logic specifies single functions in their behaviour (effect), algebraic specifications describe the interaction between several functions.
Structure charts describe functional hierarchies together with the flow of information.
For package diagrams and component diagrams, we also need a new view of the software.
source code subsystems
binary code subsystems
Functional
hierarchy
Business
Process
Infor- mation
Flow
effect of a function
interaction between functions
effect of functions to data
Data
structures
Entity types and relations
Class
structures n
Control
structures
Data-Oriented View
Object- Oriented View
Algorith- mic View
component- oriented view
Functional View

16. Combination of basic concepts in object-oriented analysis
OOA 1990
sequence diagram
ER (Entity Relationship)
class diagram
pseudo code
state
automaton
collabo-ration diagram
use case diagram
entities & relations
class structures
control structures
finite automaton
interaction structures
work flow
Contents:
Basic concepts will be combined to comprehensive methods: OO Analysis, Structured Analysis, Real-time Analysis
For the first phase of software development – the analysis and definition phase – there are several methods to support activities in that phase. The first method which is mentioned at this slide is OO Analysis. The message of this picture: There are several basic concepts to be included in OOA (7 notational forms are employed).
legend: A B: A is contained in B A B: A is implicitly contained in B

17. Combination of basic concepts in structured analysis
SA 1979
decision table
decision tree
pseudo code
data dictionary
data flow diagram
function tree
functional hierarchy
information flow
data structures
control structures
Contents:
Structured analysis is the elder method. However, it is still in use. This slide covers 6 notational forms to be included in structured analysis.
legend: A B: A is contained in B A B: A is implicitly contained in B

18. Combination of basic concepts in structured analysis and real-time analysis
decision table
decision tree
pseudo- code
data dictionary
data flow diagram
state
automaton
ER (entity relationship)
RT 1987
information flow
data structure
control structures
finite automaton
entities & relations
Contents:
This is the similar information concerning real-time analysis.
Remark:
OOA and structured analysis are part of this course, RT is not.