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Administration
a)
b)
A
B
grant?
z=0
z<=2
UniSpec
u<=2
pub?
pub?
grant?
grant?
u=0
patent!
coin!
grant?
pub?
u>2
u<=20
grant?
D
C
grant?
z=0
pub?
patent!
z<=2
u=0
patent!
grant?
grant?
patent
grant
grant
patent
pub
coin
Fig. 2.
a)Universityspecification
UniSpec
.b)Specificationofan
Administration
.
3 Design Methodologies
In the following we introduce three different development methodologies sup-
ported by our framework. These development methodologies are in no way in
conflictwitheachother,butshouldmorebeseenasprototypework-flowsthatin
aconcretedevelopmentprocesswouldbecombined.Firstwepresenttherunning
examplethatwillbeusedinpresentingthemethodologies.
Theexampleisbasedonaverysimplifiedviewofamodernuniversity.The
purposeofthe universityisto fileasmanypatentsaspossible.Moreprecisely
the requirements imposed on the university is given by the TIOA
UniSpec
as
presentedinFigure2a.Theborderaroundthespecificationshowstheinputand
output sort by incoming and outgoingarrowsrespectively. The initial state of
thespecificationismarkedbyadoublecircledstate.Giventhattheuniversity
receivesagrant(solidtransitionmarkedwith
grant?
)afteradelayoflessthan
twotimeunits itwilloutput(dashedtransitionmarkedwith
patent!
)apatent
withinthenext20timeunits.Ifthefirstgrantcomesaftermorethantwotime
unitsoranysubsequentgrantcomesmorethantwotimeunitsafterapatenthas
beenfiledthenthebehaviouroftheuniversitybecomesunpredictable,whichis
modelledbytheleftmoststateinthespecification.
Stepwise Refinement.
The first methodologypresented is the classic top-down
developmentthrough
stepwisedecomposition andrefinement
.Startingfromthe
overall specification of Figure 2a one can refine this into a specification that
containsseveralparallelcomponents.Therefinementisbasedonaknowledgeof
howthesystemunderdesignissupposedtomeettheoverallrequirements.This
refinedspecificationcanagainberefinedfurther,untilthedesiredlevelofdetail
hasbeenreached.Itisimportanttonotethatthe
independentimplementability
propertyallowsfortheserefinementstepstobetakenforindividualcomponents,
greatlyincreasingthescalabilityoftheframeworkthroughcompositionaldesign.
Wewilldecomposethe
University
specificationintothreecomponents:anAd-
ministration,aCoffee/TeamachineandaResearcher.Theresponsibilityofthe
Administration
(Figure 2b) is to convert the grants provided to the University
into coins that can be used in the coffee and tea machine. The coffee and tea
