PETROV / Russel, N., et al. Workflow Control-Flow Patterns. A Revised View

Pattern

Score

Motivation

41

(tm)

+

Supported by including a weighted edge after the MI

activity to any subsequent activity.

42

(ts)

+

Supported by linking multiple outgoing arcs from an

activity (one for each execution thread required) to

a MergeNode which then directs the various initiated

threads of control down the same branch.

43

(exp-t)

+

Supported via the ActivityFinalNode construct.

Pattern

Score

Motivation

1

(seq)

+

Directly supported, i.e., events can be used to connect

functions in a sequence.

2

(par-spl)

+

Supported by the AND-split connector.

3

(synch)

+

Supported by the AND-join connector.

4

(ex-ch)

+

Supported by the OR-split connector. However, no

language is given to describe the conditions for taking

a branch.

5

(simple-m)

+

Supported by the XOR-join connector.

6

(m-choice)

+

Supported by the OR-split connector.

7

(s-sync-m)

+

Supported by the OR-join connector. However, as de-

scribed in [Kin06], the OR-join connector creates a

paradox when combined with loops (i.e. the \vicious

circle"). The desirable semantics would be to wait un-

til no new folder can reach the OR-join. However, one

connector may depend on the other and vice versa.

The ARIS simulator uses a rather odd solution for

this dilemma: the OR-join connector has a time-out

mechanism attached to it. The join waits for a pre-

speci¯ed time and then consumes all folders that are

there.

8

(multi-m)

{

Not supported. When using an XOR-join connector

only one incoming folder is expected. Most papers

and books on EPCs state that the XOR-join should

block if multiple folders arrive. However, the ARIS

simulator implements this in a slightly di®erent way.

If multiple folder arrive at exactly the same time, they

are ignored. Otherwise, each folder is passed on.

9

(s-disc)

{

Not supported as there is no notion of ignoring subse-

quent folders and then resetting.

10 (arb-c)

+

Directly supported as there are no limitations on the

graph structure.

11 (impl-t)

+

Directly supported. Note that there may be many end

events and only if no element is enabled for a given

instance does the instance terminate.

12 (mi-no-s)

{

This is not supported. There is no explicit notion

of instances and there is no notation for inter-process

connections.

13 (mi-dt)

{

Not supported. The only way to realize this is by

making copies and putting them in parallel.

14 (mi-rt)

{

Not supported.

15 (mi-no)

{

Not supported.

Pattern

Score

Motivation

16

(def-c)

{

Not supported. The split and join connectors are exe-

cuted when they become enabled. Therefore, an XOR-

split makes an immediate decision and this choice can-

not be deferred.

17

(int-par)

{

Not supported.

18

(milest)

{

Not supported. Although EPCs contain events, it is

not possible to check states and act accordingly.

19

(can-a)

{

Not supported. There is no cancellation feature.

20

(can-c)

{

Not supported.

21

(str-l)

{

Not supported. There are only arbitrary cycles.

22

(recur)

{

Not supported.

23

(t-trig)

{

Not supported.

24

(p-trig)

+/{

EPCs allow for multiple input events and these could

be interpreted as persistent triggers. However, since

it is not possible to di®erentiate between the creation

of an instances and subsequent events and there is no

implementation of this concept, we rate this as partial

support.

25

(can-r)

{

Not supported. There is no cancellation feature.

26

(can-mi)

{

Not supported.

27

(comp-mi)

{

Not supported.

28

(b-disc)

{

Not supported.

29

(c-disc)

{

Not supported.

30

(s-pjoin)

{

Not supported.

31

(b-pjoin)

{

Not supported.

32

(c-pjoin)

{

Not supported.

33

(g-and-join)

+/{

Most papers and books on EPCs assume that joins

block if multiple folders arrive. However, the ARIS

simulator implements this more like in a Petri net.

34

(st-pjoin-mi)

{

Not supported.

35

(c-pjoin-mi)

{

Not supported.

36

(dyn-pjoin-mi)

{

Not supported.

37

(a-sync-m)

+

See pattern 7. The language allows for this. How-

ever, we know of no work°ow management systems

that implement this. Note that the ARIS simulator

uses a rather odd solution: the OR-join connector has

a time-out mechanism attached to OR-joins, i.e., the

join waits for a pre-speci¯ed time and then consumes

all folders that are pending.

38

(g-sync-m)

{

See pattern 7. The language allows for this. How-

ever, we know of no work°ow management systems

that implement this. Note that the ARIS simulator

uses a rather odd solution: the OR-join connector has

a time-out mechanism attached to OR-joins, i.e., the

join waits for a pre-speci¯ed time and then consumes

all folders that are pending.

Pattern

Score

Motivation

39

(crit-sec)

{

Not supported. There is no way to create a kind of

mutual exclusion state.

40

(int-rout)

{

Not supported.

41

(tm)

{

Not supported. It is impossible to merge a speci¯ed

number of threads into one.

42

(ts)

{

Not supported. It is impossible to merge a speci¯ed

number of threads into one.

43

(exp-t)

{

Process instances complete only when no remaining

element are enabled.