7RSRORJLFDO&RQVWUDLQWVLQ6KLS'HVLJQ
Lluís Solano*, Iñigo Gu ea** and Pe e B une *

&RPSXWHU*UDSKLFV6HFWLRQ6RIWZDUH'HS3RO WHFKQLFDO8QLYHUVLW RI&DWDOXQ D%DUFHORQD6SDLQ

VRODQR#OVLXSFHVSHUH#OVLXSFHV

6(1(5±,QJHQLHU D 6LVWHPDV%DUFHORQD6SDLQ
LQLJRJXUUHD#VHQHUHV
.H ZRUGVTopological cons ain s, ship design, objec o ien ed me hods, pa e n-based design.
$EVWUDFWIn his pape we p opose a gene ic and in eg a ed da a s uc u e ha is decoupled o m he p oduc
model da abase in o de o manage and upda e he geome ic elemen s (pa s) ela ed wi h
WRSRORJLFDO FRQVWUDLQWV. We p esen a p ac ical applica ion in he case o ship design. In ship
design i is necessa y o manage and o deal wi h a huge numbe o componen s and ela ionships.
The da a s uc u e is based on a di ec ed g aph. The so wa e design ollows objec o ien ed
echniques and pa e n-based design. Using class pa e ns o implemen he g aph and o manage
he opological cons ain s pe o ms high eusabili y o he p oposed solu ion.
 ,QWURGXFWLRQ
Du ing las yea s, solid modeling echniques and 3D isualiza ion me hods ha e been
inco po a ed in CAD/CAM Sys ems used in Shipbuilding (Aa nio 2000). This, in
conjunc ion wi h he d ama ic imp o emen o he pe o mance o compu e s and
g aphics de ices, has led o he in ensi e use o 3D design echniques in many shipya ds
(Alonso 1996).
FORAN (Ga cia 1994) is a CAD/CAM sys em speci ically o ien ed o shipbuilding, used
in mo e han 100 shipya ds all o e he wo ld. One o he key ea u es o FORAN is o
c ea e and o manage a ship p oduc model in a single da abase con aining all ship
in o ma ion in a concu en mul i-use en i onmen .
The p oduc model is a comple e ep esen a ion o he ship as an en i y o be designed,
ab ica ed, moun ed, ope a ed and main ained. The p oduc model con ains 3D
geome ical da a, in o ma ion abou he s uc u e o he p oduc (eg. he o ganiza ion o
he ship componen s by sys ems, blocks and zones), elemen a ibu es (ma e ials and
o he echnological p ope ies) as well as all he necessa y in o ma ion, documen s and
schedules o he ship ab ica ion and moun ing p ocess (Du an 1995). Geome ic,
enginee ing and manu ac u ing da a a e eco ded and main ained by he sys em, as well
as hei ela ionships.
FORAN is now used in many shipya ds o he 3D de ail design o he hull s uc u al and
ou i ing elemen s o ships ( igu e 1). The inco po a ion o lexible ools o he
managemen o he ela ionships and dependencies among he pa s o he model,
inc eases he po en ial o main ain changes in he design along he li e cycle o he
p oduc . I is use ul o include in he p oduc model opological da a abou he
ela ionships and dependencies among componen s. This pape add esses he use o
objec o ien ed echniques and pa e n-based design o manage ela ionships and
dependencies among pa s.
Figu e 1: Example o subsec ion o 3D ship s uc u e.
This pape is s uc u ed in he ollowing way. Fi s , he basic shipbuilding p ocess is
desc ibed and explained om he design cycle. In his p ocess a ises he p oblem o
keeping ack o he ela ionship be ween he hull ship and he s uc u e and componen s
pa s o a ship. A e ha , some de ini ions a e made and he p oblem is o malized.
Finally, a solu ion is p oposed and discussed using objec o ien ed echnologies.
 352%/(0'(6&5,37,21
The s a ing poin o shipbuilding enginee ing p ocess is he design o he hull su ace
model. This ask akes a conside able amoun o ime o be comple ed. The esul ing
p oduc is an essen ial in o ma ion o he ollowing s eps. Once a p elimina y hull
su ace model is ob ained, he ollowing p ocesses can s a . Rela ed wi h he hull he e
a e all he ship s uc u al elemen s. F om he ini ial hull su ace model s a s he design o
s uc u al pa s as decks, ames, panels and pla es, and he componen s and de ices
(pipes, pumps, al es, e c.) ha a e loca ed o e he ship s uc u e ( igu e 2).
Usually, design in shipbuilding en i onmen is pe o med om a se o ship componen s
ha a e ins an ia ed wi h speci ic pa ame e s. Fo each pa , i s loca ion and posi ion is
de ined oge he wi h i s ela ionships wi h o he pa s. Fo ins ance, a pump is loca ed
ela ed o he deck posi ion. In his sense, he design can be unde s ood as an assembly
design wi h a e y e y la ge numbe o componen s.
In pa allel o he design o s uc u al pa s based on he hull, he su ace model is e ined
and ai ed, wi hou p e en ing o he asks om going on (Rod iguez 2000). Once he
su ace model is inished, and using an in eg a ed sys em he wo k pe o med on he
p elimina y model mus be au oma ically upda ed.
Figu e 2: Example o ship s uc u e.
The managemen o he ela ionships and dependencies among he pa s in ol ed and he
au oma ic upda e o he geome y a e necessa y in o de o dec ease he enginee ing
asks. The ela ionships de ined among di e en componen s allow es ablishing
dependencies in changes. I an elemen A is modi ied, he elemen s depending on A and
ela ed wi h A, mus be upda ed in posi ion, dimension o bo h. We de ine hese
dependency ela ions among he in ol ed elemen s as WRSRORJLFDOFRQVWUDLQWV.
7RSRORJLFDOFRQVWUDLQWV ha e o be kep in he p oduc model o main ain changes in he
design and o upda e he loca ion, shape and dimensions o he componen s and pa s.
Some o he s uc u al pa s a e di ec ly ela ed wi h he hull su ace. In ac , he e a e
componen s such as ames, which hey a e i on he hull and ollow a cu e on he hull
su ace. This means ha any change in he hull su ace has o be ansmi ed o he ela ed
componen s. A modi ica ion o e inemen in he hull o he ship implies o edesign he
dimension and posi ion o he s uc u al ela ed pa s as deck su aces, panels and pla es.
Using WRSRORJLFDOFRQVWUDLQWV he pa s can be upda ed in an au oma ic way.
Modeling pa s ha a e ela ed wi h WRSRORJLFDO FRQVWUDLQWV, whe e he loca ion and
dimension o a pa depend on he dimensions and loca ions o o he s pa s is a o m o
DGDSWLYHPRGHOLQJ.
Mo e speci ically, le us conside he example in Figu e 3 ha shows a simpli ied
ans e sal sec ion o hal ship.
Figu e 3: Simpli ied ans e sal sec ion o a hal ship.
Ship hull modi ica ions mus be p opaga ed o he main deck, con iguous panels, lowe
decks and cen e plane e e ence, as hey p oduce changes o hei shape o loca ion. The
cen e plane e e ence mus p opaga e i s shape modi ica ions o he di e en decks and
pla es. Changes in he shape o loca ion o he lowe decks can modi y he posi ion o he
ship equipmen ; his o ces speci ic modi ica ions in he associa ed pipes which end up in
changes in he panels ha mus be c ossed by he pipes.
Figu e 4 shows he co esponding opological cons ain s o Figu e 3 componen s.
Figu e 4: Example o opological cons ain s among ship componen s.
The case explained abo e is a simpli ied case in o de o s a e he p oblem. In ac , in eal
ship design, a huge numbe o componen s in each one o ship sec ions a e in ol ed. In
a e age, he e can be om i een o a hund ed sec ions and om a dozen o se e al
hund eds o s uc u al componen s as ames, pla es, decks, and panels.
 62/87,21'(6&5,37,21
A ship is designed hie a chically, by composi ion o simple pa s in o mo e complex
ones. The na u al way o ep esen ing he dependencies and ela ionships is using a
di ec ed acyclic g aph (Rappopo 1993). F om a di ec ed acyclic g aph ha ep esen s
he opological cons ain s among ship componen s, i is possible o compu e he
sequence o pe o m he au oma ic upda e o he componen s.
We de ine he WRSRORJLFDOFRQVWUDLQWJUDSK as a di ec ed acyclic g aph whe e nodes a e
componen s o a design and edges ep esen he opological cons ain s.
The upda e p ocess o he componen s ela ed wi h WRSRORJLFDO FRQVWUDLQWV has o be
pe o med in a speci ic o de . In Figu e 2, he e alua ion o node P has as a p e equisi e
he e alua ion o nodes Q, B, C, and H. To upda e he componen s a e a change, i is
necessa y o p ocess he nodes in such an o de ha no node is p ocessed be o e any node
which poin s o i .
Using a WRSRORJLFDOVRUWLQJ (Aho 1983) i is possible o compu e a linea o de ing o he
g aph nodes, such ha i he e is an edge om node i o node j, hen in he linea
o de ing, node i appea s be o e node j.
7RSRORJLFDO VRUWLQJ is based on a g aph dep h- i s sea ch. The cos o a WRSRORJLFDO
VRUWLQJ is linea (O(n) whe e n= numbe o nodes). In he case o Figu e 4, he WRSRORJLFDO
VRUWLQJ p oduces he sequence: C H Q A B F P E D.
A gene ic and in eg a ed da a s uc u e, decoupled om he p oduc model da abase, is
p oposed ( igu e 5). This da a s uc u e allows managing and upda ing he geome ic
elemen s (pa s) ela ed wi h WRSRORJLFDO FRQVWUDLQWV. The da a s uc u e is based on a
di ec ed implici g aph whe e he nodes a e ship s uc u al componen s ha keep
hemsel es he lis o hei ela ed componen s (WRSRORJLFDO FRQVWUDLQWV). The g aph is
explici ly a e sed when he upda e p ocess is needed. The ship s uc u e upda e is
pe o med by a se o class objec s ha ha e access o he ship s uc u e componen s.
The p esen so wa e de elopmen is based in objec o ien ed echniques and pa e n-
based design (Gamma 1994) in o de o ha e a high le el o so wa e eusabili y and da a
s uc u e decoupled.
All he pa s in he ship s uc u e ha a e ep esen ed as g aph nodes can depend on o he
pa s o hey may ha e pa s depending on hem. To implemen his beha iou we use a
a ia ion o he Obse e pa e n. Gene ically, Obse e pa e n de ines a one- o-many
dependency so ha when one objec changes i s s a e, all i s dependen objec s a e
no i ied and a e upda ed au oma ically. In he Obse e pa e n an i em, he 6XEMHFW, has a
se o i ems, he 2EVHUYHUV, ha depend on him. When he 6XEMHFWis modi ied, i no i ies
o all i s 2EVHUYHUV he modi ica ion and hey upda e hei s a e, i i is necessa y. In ou
a ia ion each ship pa is bo h 2EVHUYHU and 6XEMHFW.
To uni y he in e aces o 2EVHUYHU and 6XEMHFW, a Facade pa e n is used. Facade
p o ides a uni ied in e ace o a se o in e aces in a subsys em. De ining a highe le el

in e ace makes he subsys em easie o use. In his way, he ship pa , h ough he Facade
is bo h an 2EVHUYHU and a 6XEMHFW.
Figu e 5: Class diag am de ined o deal wi h opological cons ain s.
Using he gene ic Obse e pa e n, when a pa is modi ied, he ela ed pa s a e upda ed
in dep h- i s sea ch h ough he implici g aph. As we ha e explained abo e, due o pa
upda e p e equisi es, i is necessa y o upda e he pa s ollowing he sequence gene a ed
om a WRSRORJLFDO VRUWLQJ. To compu e he WRSRORJLFDO VRUWLQJ and o begin he pa s
upda ing, he Subjec QRWLI me hod is ede ined.
Wi h his app oach we ha e modi ied he Obse e pa e n in o de o ep esen an
e icien ela ion and e alua ion scheme o p oblems ha can be ep esen ed wi h acyclic
g aphs and need o be e alua ed using WRSRORJLFDOVRUWLQJ. The WRSRORJLFDOVRUWLQJ is no
always compu ed. Each ime a pa is modi ied he WRSRORJLFDO VRUWLQJ o he g aph is
locally e alua ed om he modi ied pa . This implies a e sals only o he ela ed pa s
in he implici s uc u e. The wo s case is i he e a e changes in a pa a he op le el o
WRSRORJLFDOFRQVWUDLQW g aph.
Modi ica ions o a pa a e no he only si ua ion in which he pa s s uc u e mus be
a e sed. A a e sal is also necessa y o p e en cyclic ela ionships when a new
WRSRORJLFDOFRQVWUDLQW is added o o check he pa s s a us in a concu en mul i-use
en i onmen wi h a uni ied p oduc model.
In o de o ha e lexible g aph a e sal s a egies he Visi o pa e n is used, adding he
Visi o s DFFHSWRU o he Facade. A Visi o ep esen s an ope a ion o be pe o med on he
elemen s o an objec s uc u e. Visi o le s de ine an ope a ion wi hou any changes in
he classes o he elemen s on which i ope a es. Using a single common s uc u e, he
Visi o pa e n allows compu ing he WRSRORJLFDOVRUWLQJ, es ing he acyclic g aph and
easily opening a doo o de ine u u e ope a ions wi hou changing he o e all da a
s uc u e.
The pa upda ing me hods a e managed using he Media o pa e n. Media o de ines an
objec ha encapsula es how a se o objec s in e ac s. Media o p omo es loose coupling
by keeping objec s om e e ing o each o he explici ly, and i le s hem modi y hei
in e ac ions independen ly. In he Media o pa e n he 0HGLDWRU in e ac s wi h he
&ROOHDJXHV The 0HGLDWRU knows he conc e e ela ions be ween he &ROOHDJXHV and
p o okes hei app op ia ed upda es.
When he 6XEMHFW upda es he 2EVHUYHU, i ac i a es he 0HGLDWRU ha is in cha ge o he
ela ion managing be ween he pa s. The 0HGLDWRU in e ac s wi h he &ROOHDJXHV ha a e
ship pa s he e o e he Colleagues ha e access o he necessa y me hods on he ship pa s
o upda e hem.
In igu e 5, he class diag am used in he da a s uc u e desc ibed abo e is shown. The
main ad an age o his da a s uc u e is ha i de ines a amewo k o plug WRSRORJLFDO
FRQVWUDLQW managemen in a p oduc model wi h mino changes. The pe sis en p oduc
model in o ma ion is in he 3DUW objec . Using inhe i ance mechanism he opological
cons ain s a e added o he p oduc model elemen s.
 &21&/86,216
In his wo k a me hod o deal wi h WRSRORJLFDOFRQVWUDLQWV in ship design en i onmen
has been p esen ed. 7RSRORJLFDOFRQVWUDLQWV play an impo an ole o keep dependencies
in he p oduc model o a ship whe e a huge numbe o pa s and in o ma ion a e
in ol ed. A di ec ed and acyclic g aph s uc u e is used o manage he WRSRORJLFDO
FRQVWUDLQWV. Based on a WRSRORJLFDO VRUWLQJ, a da a s uc u e using objec o ien ed
echnologies and pa e n-based design has been desc ibed. The used pa e ns ha e been
designed in o de o achie e he equi ed unc ionali y and beha iou . Pa e n-based
design pe o ms a high le el o eusabili y. The p oposed solu ion is decoupled om he
p oduc model and i is use ul o implemen DGDSWLYH PRGHOLQJ schemes. Fu u e wo k
includes he s udy o pa alleliza ion echniques o speed up he upda e p ocess in he
p oduc model.
5()(5(1&(6
Aa nio, M.,(2000). Ea ly 3-D Ship Models Enables New Design P inciples and Simula ions. In 
VW
,QWHUQDWLRQDO (XURFRQIHUHQFH RQ &RPSXWHU $SSOLFDWLRQV DQG ,QIRUPDWLRQ 7HFKQRORJ  LQ WKH 0DULWLPH
,QGXVWULHV&203,7¶, pp. 5-17.
Aho, J., Hopc o , J., and Ullman, J. (1983)'DWD6WUXFWXUHVDQG$OJRULWKPV, Addison-Wesley.
Alonso, F., Anduja , C., B une , P., Ga cia, L., Na azo, I., and Vinacua, A. (1996). Vi ual Reali y Tools In
Shipbuilding Design. In 7HDP&$', pp.39-43.
Du an, J., Puzas, M.J., Alonso, F., and Ga cia,L. (1995). The use o a 3D p oduc model o ien a ed
CAD/CAM Sys em in a small/medium size shipya d. In &$'$3.
Gamma, E., Helm, R., Johnson, R., and Vlissides, J. (1994). 'HVLJQ3DWWHUQV(OHPHQWVRI5HXVDEOH2EMHFW
2ULHQWHG6RIWZDUH. Addison-Wesley.
Ga cia, L., Fe nandez, V., and To oja, J. (1994). The Role o CAD/CAE/CAM in enginee ing o
p oduc ion. In ,&&$6.
Rappopo , A. (1993). A Schema o Single Ins ance Rep esen a ion in Hie a chical Assembly G aphs. In
Falcidieno and T.Kunii (eds): 0RGHOLQJLQ&RPSXWHU*UDSKLFV. Sp inge Ve lag, pp. 213-223.
Rod iguez, A., Vi o, M. and Vinacua, A. (2000). New Tools o Hull Su ace Modelling, In 
VW
,QWHUQDWLRQDO
(XURFRQIHUHQFH RQ &RPSXWHU $SSOLFDWLRQV DQG ,QIRUPDWLRQ 7HFKQRORJ  LQ WKH 0DULWLPH ,QGXVWULHV
&203,7¶, pp. 400-411.