Model-based Software Engineering for/with Petri Netsekki/teaching/external/MBSE-PN2019/...apply for trip support trip book trip approve trip send trip form make trip fill in trip form

Model-based Software Engineeringfor/with Petri netsBehaviour Modelling (and its challenges)Ekkart Kindler

Ekkart Kindler

2MBSE f/w Petri Nets:Challenges of Behaviour Modelling

Motivation

Ekkart Kindler


EMF/GMF Technology

:Place

:Transition

:Arc

:Transition

:Place

:Arc

:Arc

source

target source

target

targetsource

:Arcsourcetarget

:Petrinet

:Token

PlaceTransition

1 source

1 targetArc

*

PetriNet

Token*

Node

Object

model

meta model

is instance of

concrete syntax abstract syntax

Place

Transition

Arc

Token

generate aneditor

Ekkart Kindler


Benefits of Modelling (cntd.)

Better Understanding

Mapping of instances to XML syntax (XMI)

Automatic Code Generation API for creating, deleting and modifying model Methods for loading and saving models (in XMI) Standard mechanisms for keeping track of changes

(observers) Editors and GUIs

Ekkart Kindler


Table of Contents

Motivation Model-based Software Engineering Business process modelling

Challenges and Problems Some Ideas modelling behaviour integration and coordination of behaviour

Discussion

Ekkart Kindler


Example: Business Trip

note

note

trip documents receipts

application form

approval

reimburse-ment form

reimburse-ment form& receipts

copy of af

determine trip data

applyfor trip

supporttrip

booktrip

approvetrip

sendtrip form

maketrip

fill intrip form

reimburseexpenses

lecturer

lecturer

lecturerlecturer

superior dean clerk

clerk

lecturer

Ekkart Kindler


“Summary”

Where does the “modelling only” idea work?

Graphical editors

Workflowmanagement

•graphics only•standard functions only

•no business logic

•standard GUI only

•business logic explicitly modelled

•dedicated modelling notation

?

Ekkart Kindlere.g. a Petri net simulator?


Ekkart Kindler


Challenges

“There are no notationsfor modelling behaviour!”

Ekkart Kindler


Challenges Adequate modelling methodologies

Coarse grain behaviour Fine grain behaviour

Mechanism for integrating and coordinating behaviour beyond invocation(calls of procedure, function, method, or service)

Integration with existing software (legacy, manually created, generated) other models (structural & behavioural)

Change mentality (change culture) Stuck with thread- and invocation-based thinking Software engineering is programming thinking

( model interpretation vs. code generation)

Ekkart Kindler


Table of Contents

Motivation Model-based Software Engineering Business process modelling

Challenges and Problems Some Ideas modelling behaviour integration and coordination of behaviour

(a vision: Event Coordination NOtation ECNO) Discussion

Ekkart Kindler2. The Event Coordination NOtation

Motivation Given some object oriented software with (or without)

explicit domain model,

model behaviour on top of it – and make these models executable.

Model behaviour on a high level ofabstraction (domain): coordination of behaviour

Integrate behaviour models with structural models Integrate different structural models and manually written

code (or code generated by different technologies)12MBSE f/w Petri Nets:Challenges of Behaviour Modelling

Meta-models / domain modelsincluding behaviour!

Ekkart Kindler


2.1 Example: Vending machine

Slot

Panel

Control

Coffee

Brewer

Output

*

**

*

*

*

Safe

Coin

Tea

1

Ekkart Kindler


Instance: Object Diagram

: Slot

:Panel

:Control

:Coffee

:Output: Safe

:Coin

:Tea

:Coffee

:Coin

:Coin

Ekkart Kindler


Coordination Diagram

Slot

insertreturn_passreset

Panel GUI

coffeeGUI

tea GUI

cancel GUI

Coffee

Output GUI

cup_in GUI

cup_out GUI

*

cup_in: 1

coffee: 1 tea: 1reset: ALL

coffee: 1tea: 1cancel: ALL

reset: ALLpass: 1

pass: 1

**

*

*

insert: 1

*

return_: ALLpass: 1

Safe

pass

GUICoin

insert GUI

passreturn_

Tea

Brewercoffee tearesetcup_in

1

Control

coffeeteacancelpassreset

Ekkart Kindler


... + Event declaration

Slot

insertreturn_passreset

Panel GUI

coffeeGUI

tea GUI

cancel GUI

Control


Coffee

Output GUI

cup_in GUI

cup_out GUI

*

cup_in: 1

coffee: 1 tea: 1reset: ALL

coffee: 1tea: 1cancel: ALL

reset: ALLpass: 1

pass: 1

*

**

*

insert: 1

*

return_: ALLpass: 1

Safe

pass

GUICoin

insert GUI

passreturn_

Tea

insert(Coin coin, Slot slot) coffee()pass(Coin coin, Slot slot) tea()return(Slot slot) cancel()reset_()

cup_in()cup_out()

Brewercoffee tearesetcup_in

1

Ekkart Kindler


Interaction

: Slot

:Panel

:Control

:Coffee

:Output: Safe

:Coin

:Tea

:Coffee

:Coin

:Coin

coffee

coffeecoffee

passpasspass

pass

coffee: 1

pass: 1

pass: 1

coffee: 1

coffee: 1

pass: 1

Ekkart Kindler


Interaction

: Slot

:Panel

:Control

:Coffee

:Output: Safe

:Coin

:Tea

:Coffee

:Coin

:Coin

coffee

coffeecoffee

passpasspass

pass

coffee: 1

pass: 1

pass: 1coffee: 1

pass: 1

Ekkart Kindler


Another Interaction

: Slot

:Panel

:Control

:Coffee

:Output: Safe

:Coin

:Tea

:Coffee

:Coin

:Coin

cancel reset

resetresetreset

return

return

cancel

resetreturn

reset: ALLcancel: ALL

reset: ALL

reset: ALLreset: ALL

return: ALL

return: ALL

Ekkart Kindler


Local behaviour: Coffee

Ekkart Kindler


Local behaviour: Coin

Ekkart Kindler


Local behaviour: Control

reset

cancel

coffee

pass

Ekkart Kindler


Local behaviour: Slot

reset

return

Ekkart Kindler


Interaction

: Slot

:Panel

:Control

:Coffee

:Output: Safe

:Coin

:Tea

:Coffee

:Coin

:Coin

cancel reset

resetresetreset

return

return

cancel

resetreturn

reset: ALLcancel: ALL

reset: ALL

reset: ALLreset: ALL

return: ALL

return: ALL

Ekkart Kindler2.2 ECNO: Basic Concepts

ElementTypes (Classes) EventTypes with

parameters

Global Behaviour: Coordination annotations for references Event type Quantification (1 or ALL)

Local behaviour (life-cycle): ECNO nets (or something else) Event binding (with parameter assignment) Condition Action


insert(Coin coin, Slot slot)

Control


Brewer

coffee tearesetcup_in

coffee: 1tea: 1reset: ALL

Ekkart Kindler2.3 ECNO: Advanced Concepts

ECNO with its basic concepts has some limitations, which makes modelling things in an adequate waya bit painful. ECNO has some additional concepts to make modelling more convenient. E.g.

Inheritants on events


Ekkart Kindler”Nicer Vendingmachine”


Ekkart KindlerBehaviour inheritance


Ekkart Kindler2.4 Example 2: Petri nets


Fire Transition t:for ALL incoming Arcs a:

for ONE source Place p of Arc a:find a token and remove it

for ALL outgoing arcs a:for ONE target Place p of Arc a:add a new Token

Transition t enabled:for ALL incoming Arcs a:

for ONE source Place p of Arc a:find a token

t

remove add

Ekkart KindlerPetri net: Abstract Syntax


Ekkart KindlerExample 2: Petri nets


Fire Transition t:for ALL incoming Arcs a:

for ONE source Place p of Arc a:find a token and remove it

for ALL outgoing arcs a:for ONE target Place p of Arc a:add a new Token

Transition t enabled:for ALL incoming Arcs a:

for ONE source Place p of Arc a:find a token

t

remove add

Ekkart KindlerECNO Semantics of PN


Ekkart KindlerResult


t1

t2t3

t4

Ekkart KindlerPetri net simulator


Ekkart Kindler2.5 ECNO: Summary


Ekkart KindlerECNO Nets

ECNO nets and the code generator are probably the largest application of the ePNK!


Ekkart KindlerBeyond Mickey Mouse


Ekkart KindlerDiscussion

Models of software on higher level of abstraction concise / adequate

Domain model including semantics

Coordination! Not invocation!

Idea: Define semantics of ECNO in ECNO itself (truely ”meta”)


Ekkart KindlerECNO: Focus

Software Engineers(vs. end-users)

Domain level(vs. low-level programming)

Coordination(vs. algorithmics/invocation/sequential flow)

Behaviour(vs. GUI)


Ekkart KindlerComment of a non-IT friend

”Oh, that’s great. Then I can also develop my own software now.”


Documents

Model-based Software Engineering for/with Petri Netsekki/teaching/external/MBSE-PN2019/...apply for trip support trip book trip approve trip send trip form make trip fill in trip form