Extending BPMN for Modeling Complex Choreographies. Gero Decker and Frank Puhlmann Hasso Plattner Institut Potsdam, Germany

Transcription

1 Extending BPMN for Modeling Complex Choreographies Gero Decker and Frank Puhlmann Hasso Plattner Institut Potsdam, Germany

2 !"77"(!"#$%+./01'#% /("+01'#%("45 <#&.//"&&9.7% /'*675%#'0195 ;'*67"01'#% #'0191/+01'# =+)*"#0!"#$%6('$./0 -./01'#1#,%!"(31/" -./01'#% /("+01'#%("4."&0 -./01'#% 2",1#& >"/"13" %21$% -./01'#% '3"( -#)% 21$&? )"& #'!"#$%.#&.//5% /'*67"01'#% #'0195!"7"/0% 2.)"(!"#$%/'*67"8 01'#%#'0195%!"#$%&'(()% *"&&+,"%!"#$%/'*67"8 01'#%#'0195% :1$$"(!"#$%21$% -./01'#% '3"(!'(()%*&, ;'*67"01'#% #'0191/+01'#!"#$% 6+)*"#0% =('$./0 Auctioning Scenario 2

3 Open Aspects Multiplicity of participants We need to distinguish the buyers Correlations Between auctioning service and bidders Participant reference passing The winning bidder needs to contact the seller 3

4 Proposed BPMN Extensions Participant sets to represent multiple participants Correlations via references Reference passing 4

5 Participant Sets Participant A participant set represents a set of participants of the same type Allows distinction between scenarios where at most one or more participants are involved in a conversation 5

6 References name name Task Task A reference is a special data element connected to a flow element It can either be written or read Write: If the flow object is a receive activity, the reference will point to the sender upon receipt Read 1: If the flow object is a send activity, the message will be sent to the participant the reference points to Read 2: If the flow object is a receive activity, the message is only awaited from the referred participant 6

7 Reference Sets name names Covers sets of participants involved in one conversation A reference set can be modified or read Modify: If the flow object is a receive activity, a reference to the sender will be added to the set Read: If the flow object is a looped activity, the reference set determines the number of repetitions or instances Looped send: A message is sent to each participant of the reference set 7

8 References Passing!"#$ %&$'(."/0 References can be passed to other participants This is done via an association between a reference (set), a message flow and a flow object 8

9 Seller Send auction creation req. Unsuccessful compl. notif. Completion notification Payment Send product bidders buyer Auctioning Service Auction creation request seller Auction begins Receive bid Auction over bids Any bids? yes no Send unsucc. completion notif. Select buyer Send completion notif. Send sorry message Send completion notif. others seller Bidder Send bid Auction over Sorry msg Completion notification Send payment Product Enhanced Auctioning Scenario 9

10 Validation Pattern BPMN ext. BPMN Send + + Receive + + Send/Receive + + Racing Incoming Messages + + One-to-many Send - + One-from-many Receive - + One-to-many Send/Receive - + Multi-reponses + + Contingent Request - +/- Atomic Multicast Notification - - Request with a Referral - + Relayed Request - + Table 1. BPMN vs. extended BPMN 10

11 X A y X A X A X A (a) Send (b) Send to Reference (c) Receive (d) Receive from Reference y y X A X A B X A B (e) Receive Reference (f) Send/Receive (g) Send/Receive from/to Reference Example: Single Transmission Bilateral Interaction Patterns 11

12 Discussion Informal style of the extensions "Heavy use" of Data Objects Not clearly specified in BPMN Related to BPEL4Chor Limited set of supported reference passing scenarios Only minor extensions to BPMN 12

13 Conclusions We showed weaknesses of the BPMN regarding choreography modeling We proposed participant sets, reference (sets) and reference passing as extensions Using only these few extensions, 11 out of 12 service interaction patterns are supported (instead of 5 out of 12) 13

14 Thank you! 14

15 ! " # )! # $%&'( )! " # $%&'( " (a) Racing incoming messages (b) One-to-many send re- (c) One-from-many ceive X y y A B (d) One-to-many send/receive Appendix I: Single Transmission Multilateral Interaction Patterns 15

16 ! " # $ % & '! " /0 1+$,2 #$%$&'( )$*'(+$,- / 1+$,2. 3 (a) Multi-responses (b) Contingent requests Appendix II: Multi Transmission Interaction Patterns 16

17 ! * %&'()! " ' +,-./0 * % & ) # $ ", # $ ( (a) Request with Referral (b) Relayed Request Appendix III: Routing Patterns 17