<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
	<!-- Global -->
	<xsd:element name="NetworkModel" type="GNMType"/>
	<!-- Complex Type Definitions -->
	<xsd:complexType name="GNMType">
		<xsd:sequence>
			<xsd:element name="Node" type="NodeType"/>
			<xsd:element name="Arc" type="ArcType" minOccurs="0" maxOccurs="unbounded"/>
			<xsd:element name="Workload" type="WorkloadType"/>
			<xsd:element name="ServiceRequest" type="ServiceRequestType"/>
		</xsd:sequence>
		<xsd:attribute name="Name" type="xsd:string" use="optional"/>
		<xsd:attribute name="Description" type="xsd:string" use="optional"/>
		<xsd:attribute name="Date-Time" type="xsd:dateTime" use="optional"/>
	</xsd:complexType>
	<xsd:complexType name="WorkloadType">
		<xsd:choice maxOccurs="unbounded">
			<xsd:element name="OpenWorkload" maxOccurs="unbounded">
				<xsd:complexType>
					<xsd:sequence>
						<xsd:element name="Transit" type="TransitType" maxOccurs="unbounded"/>
					</xsd:sequence>
					<xsd:attribute name="WorkloadName" type="xsd:ID" use="required"/>
					<xsd:attribute name="ArrivalRate" type="nonNegativeFloat" use="optional" default="1"/>
					<xsd:attribute name="ArrivalRateVar" type="xsd:string" use="optional"/>
					<xsd:attribute name="TimeUnits" type="TimeUnitsType" use="optional"/>
					<xsd:attribute name="ArrivesAt" type="xsd:IDREF" use="required"/>
					<xsd:attribute name="DepartsAt" type="xsd:IDREF" use="required"/>
				</xsd:complexType>
			</xsd:element>
			<xsd:element name="ClosedWorkload" maxOccurs="unbounded">
				<xsd:complexType>
					<xsd:sequence>
						<xsd:element name="Transit" type="TransitType" maxOccurs="unbounded"/>
					</xsd:sequence>
					<xsd:attribute name="WorkloadName" type="xsd:ID" use="required"/>
					<xsd:attribute name="NumberOfJobs" type="xsd:nonNegativeInteger" use="required"/>
					<xsd:attribute name="ThinkTime" type="nonNegativeFloat" use="optional" default="0"/>
					<xsd:attribute name="ThinkTimeVar" type="xsd:string" use="optional"/>
					<xsd:attribute name="TimeUnits" type="TimeUnitsType" use="optional"/>
					<xsd:attribute name="ThinkDevice" type="xsd:IDREF" use="required"/>
					<!-- <xsd:attribute name="NumberOfJobsVar" type="xsd:string" use="optional"/> -->
				</xsd:complexType>
			</xsd:element>
			<xsd:element name="ExternalTrigger" maxOccurs="unbounded">
				<xsd:complexType>
					<xsd:attribute name="WorkloadName" type="xsd:ID" use="required"/>
					<xsd:attribute name="ArrivalRate" type="nonNegativeFloat" use="optional" default="1"/>
					<xsd:attribute name="ArrivalRateVar" type="xsd:string" use="optional"/>
					<xsd:attribute name="TimeUnits" type="TimeUnitsType" use="optional"/>
					<xsd:attribute name="ArrivesAt" type="xsd:IDREF" use="required"/>
				</xsd:complexType>
			</xsd:element>
			<xsd:element name="InternalTrigger" maxOccurs="unbounded">
				<xsd:complexType>
					<xsd:attribute name="WorkloadName" type="xsd:ID" use="required"/>
				</xsd:complexType>
			</xsd:element>
		</xsd:choice>
	</xsd:complexType>
	<xsd:complexType name="NodeType">
		<xsd:choice maxOccurs="unbounded">
			<xsd:element name="Server" maxOccurs="unbounded">
				<xsd:complexType>
					<xsd:attribute name="Name" type="xsd:ID" use="required"/>
					<xsd:attribute name="Quantity" type="xsd:nonNegativeInteger" use="required"/>
					<xsd:attribute name="SchedulingPolicy" type="SchedulingType" use="required"/>
				</xsd:complexType>
			</xsd:element>
			<xsd:element name="WorkUnitServer" maxOccurs="unbounded">
				<xsd:complexType>
					<xsd:attribute name="Name" type="xsd:ID" use="required"/>
					<xsd:attribute name="Quantity" type="xsd:nonNegativeInteger" use="required"/>
					<xsd:attribute name="SchedulingPolicy" type="SchedulingType" use="required"/>
					<xsd:attribute name="TimeUnits" type="TimeUnitsType" use="optional"/>
					<xsd:attribute name="ServiceTime" type="nonNegativeFloat" use="optional" default="0"/>
					<xsd:attribute name="ServiceTimeVar" type="xsd:string" use="optional"/>
				</xsd:complexType>
			</xsd:element>
			<xsd:element name="SourceNode" maxOccurs="unbounded">
				<xsd:complexType>
					<xsd:attribute name="Name" type="xsd:ID" use="required"/>
				</xsd:complexType>
			</xsd:element>
			<xsd:element name="SinkNode" maxOccurs="unbounded">
				<xsd:complexType>
					<xsd:attribute name="Name" type="xsd:ID" use="required"/>
				</xsd:complexType>
			</xsd:element>
		</xsd:choice>
	</xsd:complexType>
	<xsd:complexType name="ServiceRequestType">
		<xsd:choice maxOccurs="unbounded">
			<xsd:element name="TimeServiceRequest" type="TimeServType" maxOccurs="unbounded"/>
			<xsd:element name="DemandServiceRequest" type="DemandServType" maxOccurs="unbounded"/>
			<xsd:element name="WorkUnitServiceRequest" type="WorkUnitServType" maxOccurs="unbounded"/>
		</xsd:choice>
	</xsd:complexType>
	<xsd:complexType name="DemandServType">
		<xsd:sequence>
			<xsd:element name="Transit" type="TransitType" maxOccurs="unbounded"/>
		</xsd:sequence>
		<xsd:attribute name="WorkloadName" type="xsd:IDREF" use="required"/>
		<xsd:attribute name="ServerID" type="xsd:IDREF" use="required"/>
		<xsd:attribute name="TimeUnits" type="TimeUnitsType" use="optional"/>
		<xsd:attribute name="ServiceDemand" type="nonNegativeFloat" use="optional" default="0"/>
		<xsd:attribute name="ServiceDemandVar" type="xsd:string" use="optional"/>
		<xsd:attribute name="NumberOfVisits" type="xsd:nonNegativeInteger" use="optional"/>
	</xsd:complexType>
	<xsd:complexType name="TimeServType">
		<xsd:sequence>
			<xsd:element name="Transit" type="TransitType" maxOccurs="unbounded"/>
		</xsd:sequence>
		<xsd:attribute name="WorkloadName" type="xsd:IDREF" use="required"/>
		<xsd:attribute name="ServerID" type="xsd:IDREF" use="required"/>
		<xsd:attribute name="TimeUnits" type="TimeUnitsType" use="optional"/>
		<xsd:attribute name="ServiceTime" type="nonNegativeFloat" use="optional" default="0"/>
		<xsd:attribute name="ServiceTimeVar" type="xsd:string" use="optional"/>
		<xsd:attribute name="NumberOfVisits" type="xsd:nonNegativeInteger" use="optional"/>
	</xsd:complexType>
	<xsd:complexType name="WorkUnitServType">
		<xsd:sequence>
			<xsd:element name="Transit" type="TransitType" maxOccurs="unbounded"/>
		</xsd:sequence>
		<xsd:attribute name="WorkloadName" type="xsd:IDREF" use="required"/>
		<xsd:attribute name="ServerID" type="xsd:IDREF" use="required"/>
		<xsd:attribute name="NumberOfVisits" type="xsd:nonNegativeInteger" use="optional"/>
	</xsd:complexType>
	<xsd:complexType name="TransitType">
		<xsd:attribute name="To" type="xsd:IDREF" use="required"/>
		<xsd:attribute name="Probability" type="nonNegativeFloat" use="optional" default="1"/>
		<xsd:attribute name="ProbabilityVar" type="xsd:string" use="optional"/>
		<xsd:attribute name="NewWorkloadName" type="xsd:IDREF" use="optional"/>
	</xsd:complexType>
	<xsd:complexType name="ArcType">
		<xsd:attribute name="Description" type="xsd:string"/>
		<xsd:attribute name="FromNode" type="xsd:IDREF" use="required"/>
		<xsd:attribute name="ToNode" type="xsd:IDREF" use="required"/>
	</xsd:complexType>
	<!-- Simple Type Definitions -->
	<xsd:simpleType name="nonNegativeFloat">
		<xsd:restriction base="xsd:float">
			<xsd:minInclusive value="0.0"/>
		</xsd:restriction>
	</xsd:simpleType>
	<xsd:simpleType name="TimeUnitsType">
		<xsd:annotation>
			<xsd:documentation>
				If time units are omitted, all specifications are assumed to be the same relative units.
			</xsd:documentation>
		</xsd:annotation>
		<xsd:restriction base="xsd:string">
			<xsd:enumeration value="day"/>
			<xsd:enumeration value="Day"/>
			<xsd:enumeration value="hr"/>
			<xsd:enumeration value="Hr"/>
			<xsd:enumeration value="min"/>
			<xsd:enumeration value="Min"/>
			<xsd:enumeration value="sec"/>
			<xsd:enumeration value="Sec"/>
			<xsd:enumeration value="ms"/>
			<xsd:enumeration value="Ms"/>
			<xsd:enumeration value="ns"/>
			<xsd:enumeration value="Ns"/>
		</xsd:restriction>
	</xsd:simpleType>
	<xsd:simpleType name="SchedulingType">
		<xsd:restriction base="xsd:string">
			<xsd:enumeration value="FCFS"/>
			<xsd:enumeration value="IS"/>
			<xsd:enumeration value="PS"/>
		</xsd:restriction>
	</xsd:simpleType>
	<xsd:annotation>
		<xsd:documentation>
		Entities (Elements):
			Arc: An Arc connects two Nodes in a QueueingNetworkModel. Traversal of an Arc represents completion of a service request at the FromNode and a new request for service at the ToNode.
			ClosedWorkload: A ClosedWorkload is a Workload with a fixed population that circulates among the Servers.
			DemandServiceRequest: A DemandServiceRequest specifies the average service demand (service time multiplied by number of visits) provided for each workload that visits the Server.
			Node: A Node represents an entity in the QueueingNetworkModel of the execution environment that either provides service or designates model topology.
			Non-ServerNode: A Non-ServerNode represents a Node of the execution environment that designates model topology but does not provide processing service.
			OpenWorkload: An OpenWorkload is a workload with a potentially infinite population where transactions or jobs arrive from the outside world, receive service, and exit. The population of the OpenWorkload at any one time is variable.
			QueueingNetworkModel: A QueueingNetworkModel represents a network of connected servers that provides processing service for Workloads.
			Server: A Server represents a Node of the execution environment that provides some processing service.
			ServiceRequest: A ServiceRequest specifies either the average TimeService or DemandService provided for each workload that visits the Server.
			SinkNode: A SinkNode represents a Node of the execution environment that designates where OpenWorkloads terminate.
			SourceNode: A SourceNode represents a Node of the execution environment that designates where OpenWorkloads originate.
			TimeServiceRequest: A TimeServiceRequest specifies the average service time and number of visits provided for each workload that visits the Server.
			Workload: A Workload represents a collection of transactions or jobs that make similar service requests from servers in the QueueingNetworkModel.
			WorkUnitServer: A WorkUnitServer represents a Server that has the same ServiceTime for all Workloads.
			WorkUnitServiceRequest: A WorkUnitServiceRequest specifies the number of visits to a WorkUnitServer.

		Attributes:
			ArrivalRate: The average rate at which transactions or jobs arrive from the outside world, receive service, and exit.
			ArrivesAt: The Name of the SoruceNode of an OpenWorkload.
			DepartsAt: The Name of the SinkNode of an OpenWorkload.
			FromNode: The Name of the origin Node of an Arc.
			NumberOfJobs: The fixed population that circulates among the Nodes.
			NumberOfVisits: The average number of visits to a Server in a ServiceRequest.
			Quantity: The number of instances of a given Server. Multiple servers have one queue for service requests.
			SchedulingPolicy: The policy used to select the next ServiceRequest to be served from a queue.
			ServiceDemand: The total demand for a service request. Demand is the product of ServiceTime and NumberOfVisits.
			ServiceTime: The amount of time required for a server to perform one unit of service. A unit of service is the amount provided for each visit to the Server.
			ThinkTime: The average interval of time that elapses between the completion of a transaction or job and the submission of the next transaction or job.
			TimeUnits: The unit of time specified in a ServiceRequest or Workload intensity. If time units are omitted, all specifications are assumed to be the same relative units.				
			ToNode: The Name of the destination Node of an Arc.
		</xsd:documentation>
	</xsd:annotation>
</xsd:schema>