B usi ness Pr oc ess Ver i fi c ati on wi th T empor al - PowerPoint PPT Presentation

B usi ness Pr oc ess Ver i fi c ati on wi th T empor al Answer S et Pr ogr ammi ng L a ura Gio rda no , Alb e rto Ma rte lli, Ma tte o Spio tta , Da nie le T he se ide r Dupré Unive rsità de l Pie mo nte Orie nta le Unive rsità di T o rino I ta ly

Go a l Cro ss-fe rtilize Busine ss Pro c e ss Mo de ling with c o ntrib utio ns fro m Re asoning about ac tions and c hange in AI a nd Answe r amming Se t Pr ogr De c la ra tive o r pro c e dura l pro c e ss mo de l • Mo de ling dire c t e ffe c ts o f a c tivitie s a s we ll a s • side e ffe c ts with c ausal r ule s (b a c kg ro und kno wle dg e ) F le xib le mo de ling o f o b lig a tio ns • Mo de ling da ta • Ve rific a tio n o f c o mplia nc e with no rms a nd • b usine ss rule s

Our c o ntrib utio n De c la ra tive / Pro c e dura l de sc riptio n o f Pro c e sse s • Ac tio n e ffe c ts • No rms • e xpre sse d in a T al e xte nsio n o f Answe r e mpor Se t Pr ogr amming (a no nmo no to nic kno wle dg e re pre se nta tio n & re a so ning fra me wo rk) Ve rific a tio n o f te mpo ra l lo g ic pro pe rtie s pe rfo rme d a s Bounde d Mode l Che c king in T e mpo ra l ASP

T he I CT 4L AW pro je c t “I CT Co nve rg ing o n L a w: Ne xt Ge ne ra tio n Se rvic e s fo r Citize ns, E nte rprise s, Pub lic Administra tio n a nd Po lic yma ke rs” 2009-2013, funde d b y Re g io ne Pie mo nte Se ve ra l pa rtne rs, inc luding , fo r pro c e dure c o mplia nc e with no rms: • I T T I G a nd L OA (CNR) • Aug e o s, SSB Pro g e tti (priva te c o mpa nie s) • Our unive rsitie s

Ac tio n the o rie s lue nts : the ir truth va lue de sc rib e s the sta te o f the wo rld, F e .g . info rme d(C) : c usto me r C is info rme d o n the firm po lic ie s Ac tion/ e ve nt : pe rfo rme d b y a n a g e nt o r “inte rna l” in the syste m; ha s dire c t a nd po ssib ly indire c t e ffe c ts o n flue nts, c a using so me sta te c ha ng e (unle ss e ffe c t a lre a dy true ) Ac tion laws : dire c t e ffe c ts o f a c tio ns Causal laws : flue nt de pe nde nc ie s, a nd the n indire c t e ffe c ts o f a c tio ns e c ondition laws : a c tio n c a n ha ppe n o nly if Pr pre c o nditio ns ho ld

T e mpo ra l mo da litie s in DL T L A pr am is b uilt fro m a c tio ns using “+” (o r), “;” ogr (se q ue nc e ) a nd “*” (ite ra tio n): a | π 1 + π 2 | π 1 ; π 2 | π * T e mpo ra l fo rmula e inc lude : 〈 π 〉 α the re is a n e xe c utio n o f π a fte r whic h α ho lds [ π ] α α ho lds a fte r a ll po ssib le e xe c utio ns o f π [a] α α ho lds a fte r a a nd the usua l te mpo ra l lo g ic mo da litie s: ◊ α (e ve ntua lly α ), □ α (a lwa ys α ), ○ α (ne xt α ) (the ir se ma ntic s is de fine d fro m the o ne o f α 𝓥 π β whic h me a ns: the re is a n e xe c utio n o f π a fte r whic h β ho lds, a nd α ho lds in a ll pre vio us sta te s)

Ac tio n la ws Ge ne ra l fo rm ( l 0 flue nt lite ra l – a flue nt o r its ne g a tio n, l 1 , ... , l n flue nt lite ra ls o r te mpo ra l lite ra ls [a] l ): □ ([a] l 0 ← l n ) 1 , ... , l m , no t l m+1 , ..., no t l me a ns tha t: a lwa ys, if a is e xe c ute d in a sta te whe re l 1 , ... , l m ho ld, a nd the re is no re a so n fo r l m+1 , ..., l n to ho ld, the n l 0 ho lds in the re sulting sta te E xa mple : □ ( [info rm]info rme d) siste nc y laws : Pe r □ ([a] l ← l , no t [a] ¬ l )

Ac tio n la ws No nde te rministic a c tio n la ws: □ ([a] (l 0 ∨ ... ∨ l k ) ← l n ) k+1 , ... , l m , no t l m+1 , ..., no t l i.e ., o ne o f l k b e c o me s true . 0 ,... , l T he y a re no t primitive , c a n b e ma ppe d to a se t o f a c tio n la ws using de fa ult ne g a tio n

Ca usa l la ws Ge ne ra l fo rm (fo r static c a usa l la ws): □ (l ← l n ) 1 , ... , l m , no t l m+1 , ... , no t l mo de l de pe nde nc ie s a nd indire c t e ffe c ts: if l 1 , ... , l m a lre a dy ho ld o r a re c a use d to ho ld, a nd l m+1 , ... , l n do no t ho ld o r a re c a use d no t to ho ld, the n “l” a lso ho lds (if its c o mple me nt ho lds b e fo re , it do e s no t pe rsist) E xa mple : □ ( ¬ c o nfirme d ← de le te d) whe re “c o nfirme d” me a ns “o rde r c o nfirme d fo r the se lle r” – b ut the c usto me r c a n withdra w its o rde r, ma king “de le te d” true a s a dire c t e ffe c t, a nd “c o nfirme d” fa lse a s a side e ffe c t

Ca usa l la ws Dynamic c a usa l la ws: □ ( О l ← t 1 , ... , t m , no t t m+1 , ... , no t t n ) i o r О l T he t i ’ s c a n b e o f the fo rms l i T he n we c a n re pre se nt side e ffe c ts o f c hang e s o f flue nts, e .g .: ¬ f , О f i.e . f b e c o me s true

Ra mific a tio ns & BPs [We b e r e t a l. 2010] pro po se to use c la use s (in c la ssic a l lo g ic ) to mo de l de pe nde nc ie s, a nd the Po ssib le Mo de ls Appro a c h [Winsle tt 1988] to de a l with ra mific a tio ns the inte nde d sta te s a fte r a n a c tio n a re tho se : whe re dire c t e ffe c ts ho ld • whe re the b a c kg ro und a xio ms a re sa tisfie d • tha t diffe r minima lly fro m the sta te b e fo re the a c tio n • But o ne o f the ir e xa mple s is: insura nc e c la im a c c e pte d whe n a c c e pte d b y re vie we r A a nd b y re vie we r B

Ra mific a tio ns & BPs I f this is mo de le d a s the ma te ria l implic a tio n: c laimAc c Re vA ∧ c laimAc c Re vB ⊃ c laimAc c e pte d a nd the PMA is use d, if A a lre a dy a c c e pte d a nd B a c c e pts, this e ithe r ma ke s c laimAc c e pte d true ... o r c laimAc c Re vA fa lse !!! T he sta tic c a usa l rule c laimAc c e pte d ← c laimAc c Re vA , c laimAc c Re vB c a n b e use d to ha ve o nly c laimAc c e pte d c ha ng e a s a side e ffe c t, while still inte nding tha t the implic a tio n ho lds

Ra mific a tio ns & BPs T he implic a tio n ma y b e fa lse if e .g . we a llo w the a c c e pta nc e to b e o ve rridde n la te r b y a supe rviso r I n this c a se dyna mic la ws a re a ppro pria te : О c laimAc c e pte d ← О c laimAc c Re vA , ¬ c laimAc c Re vB, О c laimAc c Re vB i.e ., if the c o njunc tio n o f a c c e pta nc e s b e c o me s true , we ha ve the side e ffe c t, whic h: re ma ins true b y de fa ult pe rsiste nc e • ma y b e ma de fa lse while its o rig ina l c a use re ma ins true •

Mo de ling Busine ss Pro c e sse s A do ma in de sc riptio n in [Gio rda no e t a l T PL P 2012] is a pa ir (Ac tio n a nd c a usa l la ws, DL T L c o nstra ints) T he c o ntro l flo w o f a b usine ss pro c e ss c a n b e mo de le d in se ve ra l wa ys (no t mutua lly e xc lusive ) Option 1 : a pro g ra m (re g ula r e xpre ssio n) in a DL T L c o nstra int: 〈π〉 ⊤ (o nly struc ture d, se q ue ntia l pro g ra ms) Option 2 : use g e ne ra l DL T L c o nstra ints, e .g . □ [a ] 〈 b 〉 ⊤ □ [a ] ◊ 〈 b 〉 ⊤ a fte r a is e xe c ute d, imme dia te ly/ e ve ntua lly b is e xe c ute d

Mo de ling Busine ss Pro c e sse s Option 3 : use Co nDe c c o nstra ints (g ive n the ir L T L c o rre spo nde nt) Option 4 : use e ffe c ts o f so me a c tio ns a s pre c o nditio ns o f o the r a c tio ns Option 5 : use a «c la ssic a l» g ra phic a l wo rkflo w no ta tio n (BPMN, YAWL ) a nd de fine a tra nsla tio n to te mpo ra l ASP Ac tua lly, g ive n tha t we tra nsla te te mpo ra l ASP to pla in ASP, we de fine d a dire c t tra nsla tio n fro m a YAWL sub se t to ASP

Da ta Ac tio ns tha t a c q uire a va lue fo r a va ria b le in a finite do ma in: no nde te rministic a c tio n la ws [ve rify_status] status(g o ld) ∨ status(silve r) ∨ status(no rmal) F o r nume ric a l da ta , we c a n use the a b stra c tio n te c hniq ue in [K nuple sc h e t a l 2010] whic h use s thre sho lds in the mo de l (XOR-splits) a nd in the fo rmula to b e ve rifie d to re duc e the do ma in to a sma ll se t o f a b stra c t va lue s

Da ta We use the no ta tio n (fro m so me ASP so lve rs) 1{[a ]R(X) | P(X)}1 a fte r a , R is true fo r e xa c tly o ne X suc h tha t P(X), sho rt fo r: [a ]R(X) ← no t [a ] ¬ R(X) , P(X) [a ] ¬ R(X) ← [a ]R(Y ) , P(X) , P(Y ) , X ≠ Y T he n «se le c t a shippe r S, a mo ng the a va ila b le o ne s, tha t is c o mpa tib le with the pro duc t P» is: 1{[se le c t_shippe r(P)]shippe r(S) | a va ila b le _shippe r(S)}1 ⊥ ← [se le c t shippe r(P)]shippe r(S) , no t c o mpa tib le (P, S)

Co mplia nc e Se ve ra l no rms a nd b usine ss rule s ha ve the fo rm «if A ha ppe ns/ is true , tha n B sha ll ha ppe n/ b e true » T his ma y me a n ve rifying the fo rmula : □ (A → ◊ B) b ut this do e s no t a llo w the «o b lig a tio n» to B to b e c a nc e lle d la te r: e .g . (o b lig a tio n to se nd g o o ds c a nc e lle d if o rde r c a nc e lle d) We the n ha ve a n e xplic it no tio n o f c o mmitme nt C( α): □ ([o rde r]C(g o o ds_se nt))

Co mplia nc e T he c o mmitme nt ma y b e c a nc e le d: □ ([c anc e l_o rde r] ¬ C(g o o ds_se nt)) a nd it is disc ha rg e d whe n fulfille d: □ ( ○ ¬ C( α ) ← C( α ) , ○ α ) (dyna mic c a usa l rule ) No w, the fo rmula to b e ve rifie d is, fo r a ll C( α ) : □ ( C( α ) → ◊ ¬ C( α ) )