None Forward Backward Both None One Both Unspecified Converging Diverging Mixed Information Physical None Private Public Parallel Sequential None One All Complex Exclusive Parallel None Standard MultiInstanceSequential MultiInstanceParallel all The referenced file must be present in the given location and must be compatible to the defined type in order to be processed. implicit all The ID must be unique. implicit all An ID must be present if the element may be referenced. ``The id is REQUIRED if this element is referenced or intended to be referenced by something else. all The Value of the attribute must be a valid mime-type. ``It MUST follow the mime-type format. The default is 'text/plain.''' all Any non-standard artifact must respect the standard flow connection rules. ``A modeler or modeling tool MAY extend a BPMN diagram and add new types of Artifacts to a Diagram. all An Artifact MUST NOT be a target for a Sequence Flow. ``An Artifact MUST NOT be a target for a Sequence Flow.'' all An Artifact MUST NOT be a source for a Sequence Flow. ``An Artifact MUST NOT be a source for a Sequence Flow.'' all An Artifact MUST NOT be a target for a Message Flow. ``An Artifact MUST NOT be a target for a Message Flow.'' all An Artifact MUST NOT be a source for a Message Flow. ``An Artifact MUST NOT be a source for a Message Flow.'' all The Value of the attribute must be a valid mime-type. ``It MUST follow the mimetype format. The default is 'text/plain.''' proc An escalationCode must be present if the escalation is used in an EndEvent or in an intermediate Event if the trigger is an Escalation. process is defined as executable ``For an End Event: If the Result is an Escalation, then the escalationCode \newline MUST be supplied [...] For an Intermediate Event within normal flow: If the trigger is an Escalation, then the escalationCode MUST be entered [...] For an Intermediate Event attached to the boundary of an Activity: proc If natural-language expressions are used the process is not executable. ``The Expression class is used to specify an Expression using natural-language text. These Expressions are not executable.'' ``The Expression class is used to specify an Expression using natural-language text. These Expressions are not executable and are considered underspecified.'' all body - all Value must conform to URI format specification. ``The language MUST be specified in a URI format.'' chor Choreographies and SubChoreographies must not contain LaneSets ``LaneSets are not used for Choreographies or Sub-Choreographies.'' all A unspecified Gateway may have any number of incoming and outgoing sequence flows. Value of attribute is ``Unspecified'' ``Unspecified: There are no constraints. The Gateway MAY have any number of incoming and outgoing Sequence Flows.'' (Table 8.46) ``A Gateway with a gatewayDirection of unspecified MAY have both multiple incoming and outgoing Sequence Flows.'' all A converging Gateway must not have more than one outgoing Sequence Flow. Value of attribute is ``Converging'' ``Converging: This Gateway MAY have multiple incoming Sequence Flows but MUST have no more than one (1) outgoing Sequence Flow.'' (Table 8.46) ``A Gateway with a gatewayDirection of converging MUST have multiple incoming Sequence Flows, but MUST NOT have multiple outgoing Sequence Flows.'' all A diverging Gateway must not have more than one incoming Sequence Flow. Value of attribute is ``Diverging'' ``Diverging: This Gateway MAY have multiple outgoing Sequence Flows but MUST have no more than one (1) incoming Sequence Flow.'' (Table 8.46) ``A Gateway with a gatewayDirection of diverging MUST have multiple outgoing Sequence Flows, but MUST NOT have multiple incoming Sequence Flows.'' all A mixed Gateway must have more than one incoming and outgoing Sequence Flow. Value of attribute is ``Mixed'' ``Mixed: This Gateway contains multiple outgoing and multiple incoming Sequence Flows.'' (Table 8.46) ``A Gateway with a gatewayDirection of mixed MUST have both multiple incoming and outgoing Sequence Flows.'' all A CollectionItem must be used if the ItemDefinition is declared as a Collection Value of attribute is ``true'' ``In cases where the data structure represents a collection, the multiplicity can be pro\-jec\-ted into the attribute isCollection. proc chor Only FlowNodes are allowed as source of a Sequence Flow. (REF.019; additional Restrictions see quotation) ``For a Process: Of the types of FlowNode, only Activities, Gateways, and Events can be the source. For a Choreography: Of the types of FlowNode, only Choreography Activities, Gateways, and Events can be the source.'' (Table 8.51)\\ proc chor Only FlowNodes are allowed as target of a Sequence Flow. (REF.020; additional ``For a Process: Of the types of FlowNode, only Activities, Gateways, and Events can be the target. For a Choreography: Of the types of FlowNode, only Choreography Activities, Gateways, and Events can be the target.'' (Table 8.51)\\ proc chor The source and target element of the sequence flow must reference the SequenceFlow definition using their incoming/outcoming attributes. implicit proc The optional attribute must not be ``false'' for executable processes. process is defined as executable ``An optional boolean value specifying whether Activities or Choreography Activities not in the model - For an executable Processes no value has the same semantics as if the value were true. - For executable Processes, the attribute MUST NOT be false.'' (Table 8.51)\\ all An Activity must not have only one outgoing conditional sequence flow. conditionExpression is present. ``If a conditional Sequence Flow is used from a source Activity, then there MUST be at least one other outgoing Sequence Flow from that Activity.'' all If an activity or gateway references a sequenceFlow as default flow - the referenced sequence Source Activity or Gateway is using the default attribute. implicit proc chor A choreography or a GlobalConversation must not reference a choreography. ``Note that this attribute is not applicable for Choreography or GlobalConversation proc chor A Sequence Flow must not cross the border of a Pool (i.e., a Sequence flow must link to elements of a single process) ``The Sequence Flows can cross the boundaries between Lanes of a Pool [...], but cannot cross the boundaries of a Pool. proc chor int value >= 0 implicit proc chor minimum ``The value of maximum MUST be one or greater, AND MUST be equal or greater than the minimum value.'' proc chor A message flow must connect 'InteractionNodes' from different Pools. ``A Message Flow MUST connect two separate Pools. They connect either to the Pool boundary or to Flow Objects within the Pool boundary. proc chor see quotation ``A GlobalConversation is a restricted type of Collaboration, it is an 'empty Collaboration'. A GlobalConversation MUST NOT contain any ConversationNodes. proc chor The value of isClosed must be equal in the collaboration and its contained choreography. Collaboration contains a Choreography. ``If a Collaboration contains a Choreography, then the value of the isClosed attribute MUST be the same in both.'' proc chor Flow Elements contained in a Lane which represents a A Lane is used to represent a Conversation. ``When a Lane (in a Process) represents a Conversation, the Flow Elements in the Lane (or elements nested or called in them) proc A Public process may not be marked as executable. ``For public Processes, no value has the same semantics as if the value were false. The value MAY not be true for public Processes.'' proc A Process must not contain Choreography Activities (derived rule from FlowElementsContainer) ``Choreography Activities MUST NOT be included as a flowElement for a Process.'' proc int value >= 1 ``The default value is 1. The value MUST NOT be less than 1.'' proc int value >= 1 ``The default value is 1. The value MUST NOT be less than 1.'' proc Either a resourceRef XOR a resourceAssignmentExpression should be used. ``resourceRef: Should not be specified when resourceAssignmentExpression is provided. [...] resourceAssignmentExpression: Should not be specified when a resourceRef is provided.''\\ proc resourceParameterBindings are only allowed if a resourceRef is specified. ``Is only applicable if a resourceRef is specified.'' proc A Task must not have a Loop and a Multi-Instance marker. ``BPMN specifies three types of markers for Task: a Loop marker or a Multi-Instance marker and a Compensation marker. The loop Marker MAY be used in combination with the compensation marker. [...] The multi-instance marker MAY be used in combination with the compensation marker. [...] The Compensation Marker MAY be used in combination with the loop marker or the multi-instance marker.''\\ proc Exactly one SubElement <ioSpecification><InputSet> must be present operationRef is present ``The Service Task has exactly one inputSet [...]'' proc At most one Subelement <ioSpecification><OutputSet> operationRef is present ``The Service Task has [...] at most one outputSet.'' proc Referenced item must be declared as InputMessage item operationRef is present ``It has a single Data Input with an ItemDefinition equivalent to the one defined by proc Referenced item must be declared as OutputMessage item. operationRef is present; operation has output message ``If the Operation defines output Messages, the Service Task proc At most one SubElement <ioSpecification><InputSet> must be present messageRef is present ``[...] constraints apply when the Send Task references a Message: The Send Task has at most one inputSet and one Data Input.'' (p.160) ``If the Send Task is associated with a Message, there MUST be at most [one] inputSet set and at most one Data Input on the Send Task.'' (p.217)\\ proc At most one SubElement <ioSpecification><DataInput> must be present messageRef is present ``[...] constraints apply when the Send Task references a Message: The Send Task has at most one inputSet and one Data Input.'' ``If the Send Task is associated with a Message, there MUST be at most [one] inputSet set and at most one Data Input on the Send Task.'' proc An Item must be referenced which must be declared in referenced Message definition messageRef (of ReceiveTask) and a dataInput is present ``If the Data Input is present, it MUST have an ItemDefinition equivalent to the one defined by the associated Message.'' proc A ReceiveTask with attribute instantiate set to true must not have any incoming sequence flow. ``This attribute MAY be set to true if the Task is the first Activity (i.e., there are no incoming Sequence Flows).'' (p.162) ``In order for the Receive Task to instantiate the Process its instantiate attribute MUST be set to true and it MUST NOT have any incoming Sequence Flow.'' proc At most one SubElement <ioSpecification><OuputSet> must be present messageRef is present ``The Receive Task has at most one outputSet'' proc At most one SubElement <ioSpecification><DataOutput> must be present messageRef is present ``The Receive Task has [...] at most one Data output.'' proc An Item must be referenced which must be declared in referenced Message definition messageRef (of ReceiveTask) and a dataOutput is present ``If the Data output is present, it MUST have an ItemDefinition equivalent to the one defined by the associated Message.'' proc If a script is present the script type must be defined. The scriptTask contains a Script subelement. ``[...] And it MUST be specified if a script is provided.'' proc At most three Markers (SubProcess Marker, Loop, Multi-Instance, Compensation, Ad-Hoc) may be used. ``A collapsed Sub-Process MAY have one to three of these other markers, in all com\-binations except that loop and multi-instance cannot be shown at the same time.'' proc Loop and MultiInstance markers must not be used in the same SubProcess. ``A collapsed Sub-Process MAY have one to three of these other markers, in all com\-binations except that loop and multi-instance cannot be shown at the same time.'' proc A Process must not contain Choreography Activities (derived rule from FlowElementsContainer) ``Choreography Activities MUST NOT be included as a flowElement for a Process.'' proc An Event Sub-Process MUST NOT have any incoming or outgoing Sequence Flows. the process is an EventSubProcess, e.g., triggeredByEvent=true ``An Event Sub-Process MUST NOT have any incoming or outgoing Sequence Flows.'' proc An Event Sub-Process MUST have exactly one Start Event. the process is an EventSubProcess, e.g., triggeredByEvent=true ``An Event Sub-Process MUST have one and only one Start Event.'' proc An Event Sub-Process MUST define at least of the following EventDefinitions: the process is an EventSubProcess, e.g., triggeredByEvent=true ``The Start Event of an Event Sub-Process MUST have a defined trigger. \textbf{problematic:parallel multiple also allowed on pg. 260} \\ proc The Transaction method SHOULD refer to a concrete technology using a specific URI. process is defined as executable ``For executable Processes, it SHOULD be set to a technology specific URI'' proc At least one Activity must be contained in an AdHocSubProcess ``The list of BPMN elements that MUST be used in an Ad-Hoc Sub-Process: Activity.'' proc Start Event, End Event, Conversations, Conversation Links ``The list of BPMN elements that MUST NOT be used in an Ad-Hoc Sub-Process: proc see quotation callableElement is referenced ``A Call Activity MUST fulfill the data requirements, as well as return the data proc At least one InputOutputBinding must be defined as the Callable Element is exposed as a Service. element is exposed as a Service; i.e. an Interface is referenced ``When a CallableElement is exposed as a Service, it has to define one or more InputOutputBinding elements.'' proc see quotation ``An InputOutputBinding element binds one Input and one Output of the InputOutputSpecification to an Operation of a Service Interface.'' proc Constraints defined for Tasks must also be fulfilled by the corresponding global variants. ``Only GlobalUserTask,GlobalManualTask, GlobalScriptTask, and GlobalBusinessRuleTask are defined in BPMN. proc Either a loopCardinality or a loopDataInputRef must be present. process is defined as executable (interpretation of 'in order to initialize a valid [...]') ``In order to initialize a valid multi-instance, either the loopCardinality Expression or the loopDataInput MUST be specified.'' proc Reference must be resolvable to a DataInput defined in the InputOutputSpecification of the Task. MultiInstanceLoopCharacteristics element is used within a Task. ``For Tasks it is a reference to a Data Input which is part of the Activity's InputOutputSpecification.'' proc Type of DataInput must be the scalar of the loopDataInput type. ``The type of this Data Input MUST the scalar of the type defined for the loopDataInput.'' proc Type of DataOutput must be the scalar of the loopDataOutput type. ``The type of this Data Output MUST the scalar of the type defined for the loopDataOutput.'' proc Expression must evaluate to a boolean. ``This attribute defines a boolean Expression [...]'' proc Expression must evaluate to a boolean. ``This attribute defines a boolean Expression [...]'' proc DataObjects may not be used outside of a (Sub-)Process. ``Data Object elements MUST be contained within Process or Sub-Process elements.'' proc DataObjects cannot specify states. \emph{\textbf{Issues:XSD allows that explicitly, sections States on p.206 also mentions the ability of defining ``Data Objects cannot specify states.'' proc Data Object Reference cannot specify item definitions \emph{\textbf{Issues:XSD allows that explicitly, sections States on p.206 also mentions the ability of defining ``Data Object Reference cannot specify item definitions'' proc Naming Convention: name = <Data Object Name> [<Data Object Reference State>] ``The names of Data Object References are derived by concatenating the name of the referenced Data proc The value of isCollection must be equal to the value in the referenced ItemDefinition. an ItemDefinition is referenced (e.g. attribute itemSubjectRef is present) ``If an itemDefinition is referenced, then this attribute MUST have the same value as the isCollection attribute of the referenced itemDefinition.'' proc A Property is only allowed within a Process, Activity or Event. ``Certain flow elements MAY contain properties, in particular only Processes, Activities, and Events MAY contain Properties. [...] Property elements MUST be contained within a FlowElement.''\\ proc InputOutputSpecifications are not allowed in SubProcesses. ``Certain Activities and CallableElements contain a InputOutputSpecification element to describe their data requirements. proc DataInputs of a top-level process must not be target of a DataAssociation. ``Data Inputs MAY have incoming Data Associations: proc The value of isCollection must be equal to the value in the referenced ItemDefinition. an ItemDefinition is referenced (e.g. attribute itemSubjectRef is present) ``If an itemDefinition is referenced, then this attribute MUST have the same value as the isCollection attribute of the referenced itemDefinition.'' proc DataOutputs of a top-level process must not be source of a DataAssociation. ``Data Outputs MAY have outgoing DataAssociations. proc The value of isCollection must be equal to the value in the referenced ItemDefinition. an ItemDefinition is referenced (e.g. attribute itemSubjectRef is present) ``If an itemDefinition is referenced, then this attribute MUST have the same value as the isCollection attribute of the referenced itemDefinition.'' proc A DataInput must be referenced by at least one InputSet. ``A single DataInput MAY be associated with multiple InputSet elements, but it MUST always be referenced by at least one InputSet.'' proc An optionalInputRef must be listed as dataInputRef. ``This association MUST NOT reference a DataInput that is not listed in the dataInputRefs.'' proc A whileExecutingInputRef must be listed as dataInputRef. ``This association MUST NOT reference a DataInput that is not listed in the dataInputRefs.'' proc Definition of an Input/Output rule: cross referencing between InputSet and OutputSet ``Specifies an Input/Output rule that defines which OutputSet is expected to be created by the Activity when this InputSet became valid. proc A DataOutput must be referenced by at least one OutputSet. ``A single DataOutput MAY be associated with multiple OutputSet elements, but it MUST always be referenced by at least one OutputSet.'' proc An optionalOutputRef must be listed as dataOutputRef. ``This association MUST NOT reference a DataOutput that is not listed in the dataOutputRefs.'' proc A whileExecutingOutputRef must be listed as dataOutputRef. ``This association MUST NOT reference a DataOutput that is not listed in the dataOutputRefs.'' proc sourceRef and targetRef must have the same ItemDefinition or a transformation must be present. ``The ItemDefinition from the souceRef and targetRef MUST have the same ItemDefinition or the DataAssociation MUST have a proc A single sourceRef must be present. no Transformation defined ``If there is no transformation defined or referenced, then only one source MUST be defined [...]'' proc For each eventDefinition a DataInput or DataOutput must be defined (depending on the type of the event) ``If the Event is associated with multiple EventDefinitions, there MUST be one Data Input (in the case of throw Events) proc An itemDefinition must be present for each eventDefintion with its corresponding Data Input/Output. ``For each EventDefinition and Data Input/Output pair, if the Data Input/Output is present, it MUST have an ItemDefinition proc EventDefinitions defined in a throw event are only valid within these element. ``These EventDefinitions are only valid inside the current Event.'' proc A Start Event must not have an incoming sequence flow. ``[...] the Start Event [...] will not have any incoming Sequence Flows'' ``A Start Event MUST NOT be a target for Sequence Flows'' proc A Start event must be present when an End event is used in the same process level. EndEvent used in process. ``If there is an End Event, then there MUST be at least one Start Event.'' proc Only messageEventDefininitions, timerEventDefinitions, conditionalEventDefinitions and signalEventDefinition are allowed for top-level process start events. StartEvent is used in a top-level process definition. ``There are seven (7) types of Start Events for top-level Processes in BPMN (see Table 10.84): None, Message, Timer, proc Referenced process must have at least one None Start Event. ``A top-level Process that has at least one None Start Event MAY be called by a Call Activity in another Process. proc No EventDefinition is allowed for Start Events in Sub-Process definitions. StartEvent is used in a sub-process definition. ``There is only one type of Start Event for Sub-Processes in BPMN (see Figure 10.82): None.'' proc A Start Event MUST be a source for a Sequence Flow. ``A Start Event MUST be a source for a Sequence Flow.'' proc A Start Event MUST NOT be a source for a message flow. ``A Start Event MUST NOT be a source for a Message Flow; it MUST NOT have outgoing Message Flows.'' proc If a Start Event is target of a MessageFlow definition, at least one messageEventDefinition must be present. The start event is target of a message flow definition. implicit proc An End Event must not have an outgoing sequence flow. ``[...] the End Event [...] will not have any outgoing Sequence Flows'' (p.246) \& \newline An End Event MUST NOT be a source for Sequence Flows; that is, there MUST NOT be outgoing Sequence Flows. An exception to this is when an End Event is used in an Expanded Sub-Process and is attached to the boundary of that Sub- Process. In this case, a Sequence Flow from the higher-level Process MAY connect from that End Event in lieu of connecting from the actual boundary of the Sub-Process. proc An end event must be present when a start event is used in the same process level. StartEvent used in process. ``If there is a Start Event, then there MUST be at least one End Event.'' proc A cancel EndEvent is only allowed in a transaction sub-process. ``This type of End is used within a Transaction Sub-Process.'' ``The Cancel End Event MUST only be used within a Transaction Sub-Process and, thus, MAY NOT be used in any other type of Sub-Process or Process.'' proc An End Event MUST have at least one incoming Sequence Flow. ``An End Event MUST be a target for a Sequence Flow. An End Event MAY have multiple incoming Sequence Flows.'' proc An End Event MUST NOT be a target for a message flow. ``An End Event MUST NOT be the target of a Message Flow; it can have no incoming Message Flows.'' proc If an end event is source of a MessageFlow definition, at least one messageEventDefinition must be present. The end event is source of a message flow definition. ``The Result attribute of the End Event MUST be set to Message or Multiple if there are any outgoing Message Flows. proc omg2011bpmn Table 10.92 proc The Transaction attribute of a Sub-Process with an attached CancelBoundaryEvent must be true. BoundaryEvent type is cancel and is attached to a Sub-Process. ``An Intermediate Event with a Cancel trigger MAY be attached to a Sub-Process boundary only if the Transaction attribute of the Sub-Process is set to true.'' proc A boundary event must not be target of a Sequence Flow. ``If the Intermediate Event is attached to the boundary of an Activity: proc A boundary event must be a source of at least a SequenceFlow. BoundaryEvent type does not contain a compensateEventDefinition. ``[If the Intermediate Event is attached to the boundary of an Activity:] An exception to this: an Intermediate Event with a Compensation trigger MUST NOT have an outgoing Sequence Flow (it MAY have an outgoing Association).''\\ proc A compensation boundary event MUST NOT have an outgoing Sequence Flow (it MAY have an outgoing Association). BoundaryEvent contains a compensateEventDefinition. ``[If the Intermediate Event is attached to the boundary of an Activity:] The Intermediate Event MUST be a source for a Sequence Flow. [...] An exception to this: an Intermediate Event with a Compensation trigger MUST NOT have an outgoing Sequence Flow (it MAY have an outgoing Association).''\\ proc Intermediate Events MUST be a target of at least a Sequence Flow. IntermediateEvent does not contain a link. ``If the Intermediate Event is used within normal flow: Intermediate Events MUST be a target of a Sequence Flow. [...] proc Intermediate Events MUST be a source of at least a Sequence Flow. IntermediateEvent does not contain a link. ``An Intermediate Event MUST be a source for a Sequence Flow. Multiple Sequence Flows MAY originate from an Intermediate Event. proc A Link Intermediate Event MUST NOT be both a target and a source of a Sequence Flow. IntermediateEvent contains a link. ``A Link Intermediate Event MUST NOT be both a target and a source of a Sequence Flow.'' \newline proc For each source Link there must exist a correspondig target. There may be multiple sources for one target. IntermediateEvent contains a "link". ``If there is a source Link, there MUST be a matching target Link (they have the same name). proc A Message Intermediate Event MAY have an incoming Message Flow or an outgoing Message Flow, but not both. Intermediate Event contains a message ``- A Message Intermediate Event MAY be the target for a Message Flow; it can have one incoming Message Flow. - A Message Intermediate Event MAY be a source for a Message Flow; it can have one outgoing Message Flow. - A Message Intermediate Event MAY have an incoming Message Flow or an outgoing Message Flow, but not both.'' proc A cancel Intermediate Event must be attached to a Transaction Sub-Process. BoundaryEvent contains a cancelEventDefinition ``The catch Cancel Intermediate Event MUST only be attached to the boundary of a Transaction Sub-Process and, thus, MAY NOT be used in normal flow.'' proc A compensation start event is only allowed for Event Sub-Processes. StartEvent contains a compensateEventDefinition ``The Compensation Start Event MAY NOT be used for a top-level Process. The Compensation Start Event MAY be used for an Event Sub-Process.'' proc The catch Compensation Intermediate Event MUST only be attached to the boundary of an Activity and, thus, MAY NOT be used in normal flow. The throw Compensation Intermediate Event MAY be used in normal flow.\\ BoundaryEvent contains a compensateEventDefinition ``The catch Compensation Intermediate Event MUST only be attached to the boundary of an Activity and, thus, MAY NOT be used in normal flow. The throw Compensation Intermediate Event MAY be used in normal flow.''\\ proc For executable Processes (isExecutable = true), if the trigger is Conditional, then a FormalExpression MUST be entered. process is defined as executable ``For executable Processes (isExecutable = true), if the trigger is Conditional, then a FormalExpression MUST be entered.'' proc A LinkEventDefinition in a Catch Event must have at least one source Element. LinkEventDefinition is used in an IntermediateCatchEvent http://www.omg.org/issues/bpmn2-rtf.open.html\#Issue15739) proc A LinkEventDefinition in a Throw Event must have exactly one target Element. LinkEventDefinition is used in an IntermediateThrowEvent http://www.omg.org/issues/bpmn2-rtf.open.html\#Issue15739) proc Links are only allowed to a target in the same process and process level. ``The use of Link Events is limited to a single Process level (i.e., they cannot link a parent Process with a Sub-Process).'' proc A messageRef must be present if the process should be executable. process is defined asexecutable ``The Message MUST be supplied (if the isExecutable attribute of the Process is set to true).'' proc An operationRef must be present if the process should be executable. process is defined as executable ``It MUST be specified for executable Processes.'' proc The None Start Event MAY NOT be used for an Event Sub-Process. (i.e. there must exist at least one EventDefinition) StartEvent is used in an Event Sub-Process. ``The None Start Event MAY NOT be used for an Event Sub-Process.'' proc A catch None BoundaryEvent is not allowed. BoundaryEvent is of type catch ``The catch None Intermediate Event MUST only be used in normal flow and, thus, MAY NOT be attached to the boundary of an Activity.'' proc Timer attributes are mutually exclusive, i.e., only one of the Attributes timeDate, timeCycle and timeDuration might be set for executable processes. process is defined as executable ``Timer attributes are mutually exclusive [...] (if the isExecutable attribute of the Process is set to true)'' proc The return type of the attribute timeDate MUST conform to the ISO-8601 format for date and time representations. ``The return type of the attribute timeDate MUST conform to the ISO-8601 format for date and time representations.'' proc The return type of the attribute timeCycle MUST conform to the ISO-8601 format for date and time representations. ``The return type of the attribute timeCycle MUST conform to the ISO-8601 format for date and time representations.'' proc The return type of the attribute timeDuration MUST conform to the ISO-8601 format for date and time representations. ``The return type of the attribute timeDuration MUST conform to the ISO-8601 format for date and time representations.'' proc A Gateway MUST have either multiple incoming Sequence Flows or multiple outgoing Sequence Flows. ``A Gateway MUST have either multiple incoming Sequence Flows or multiple outgoing Sequence Flows (i.e., it MUST merge or split the flow).'' proc An Event Gateway MUST have two or more outgoing Sequence Flows. ``An Event Gateway MUST have two or more outgoing Sequence Flows.'' proc The outgoing Sequence Flows of the Event Gateway MUST NOT have a conditionExpression. ``The outgoing Sequence Flows of the Event Gateway MUST NOT have a conditionExpression.'' proc An eventBasedGateway may only be connected to an ReceiveTask or one of the following intermediate Events: ``Event-Based Gateways are configured by having outgoing Sequence Flows target an Intermediate Event or a Receive Task in any combination proc If Message Intermediate Events are used in the configuration, then Receive Tasks MUST NOT be used in that configuration and vice versa. ``If Message Intermediate Events are used in the configuration, then Receive Tasks MUST NOT be used in that configuration and vice versa.'' proc Receive Tasks used in an Event Gateway configuration MUST NOT have any attached Intermediate Events. ``Receive Tasks used in an Event Gateway configuration MUST NOT have any attached Intermediate Events.'' proc Targets of an EventBasedGateway must not have any other incoming SequenceFlow. ``Target elements in an Event Gateway configuration MUST NOT have any additional incoming Sequence Flows (other than that from the Event Gateway).'' proc When an EventBasedGateway is used to instantiate a process instance no Incoming Sequence Flow is allowed. Attribute instantiate is true ``In order for an Event Gateway to instantiate a Process, it MUST not have any incoming Sequence Flows.'' proc A compensateBoundaryEvent must be connected with an Association to a Compensation Activity. BoundaryEvent has a compensateEventDefinition ``This compensation is modeled with a specialized Compensation Activity, which is connected to the boundary Event through an Association'' proc The associated Activity must be a Task or a Sub-Process which is marked for compensation (i.e., isForCompensation=true) BoundaryEvent has a compensateEventDefinition ``The Compensation Activity, which can be either a Task or a Sub-Process, has a marker to show that it is used for compensation only and is proc The value must be in mime-type format. ``This attribute value MUST be specified with a mime-type format.'' proc Only messageEventDefininitions, escalationEventDefinitions, errorEventDefinitions, cancelEventDefinitions, compensationEventDefinitions, signalEventDefinitions and terminateEventDefinitions are allowed for end events. ``There are nine types of End Events in BPMN: None, Message, Escalation, Error, Cancel, Compensation, Signal, Terminate, and Multiple.'' \& Table 10.88 proc Only messageEventDefininitions, timerEventDefinitions, escalationEventDefinitions, errorEventDefinitions, (Table 10.90) proc Only messageEventDefininitions, timerEventDefinitions, conditionalEventDefinitions, (Table 10.89) proc Only messageEventDefininitions, escalationEventDefinitions, compensationEventDefinitions, linkEventDefinitions and (Table 10.89) proc If a start event is used to initiate a process, all flow nodes (besides start events, boundary events and catching Link events, compensation activies and event subprocesses) must have an incoming sequence flow. StartEvent is used in a process level. ``A Start Event is OPTIONAL: a Process level [...] MAY (is NOT REQUIRED to) have a Start Event.'' (p.238) \newline proc If end events are used, all flow nodes other (besides end events, throwing Link events, compensating activities and event subprocesses) must have an outgoing sequence flow. EndEvent is used in a process level. ``An End Event is OPTIONAL: a given Process level [...] MAY (is NOT REQUIRED to) have this shape [...] proc A Sequence Flow must not cross the border of a SubProcess, but must link to the SubProcess itself (i.e., a Sequence flow must not to elements within a subprocess) Silver2011