CHAPTER 4
Activity Modeling Constructs

The SIMPROCESS Activities that were not covered in Chapter 2, "SIMPROCESS Basics," beginning on page 63, can be divided into two categories: Entity Related and Resource Related.

Entity Related

These Activities coordinate groups of Entities and includes:

· Assemble. Receives two or more Entities and assembles them into a single Entity that is released.

· Branch. Routes Entities through different Connectors of the model network.

· Merge. Routes Entities from different Connectors onto one Connector.

· Batch. Stores Entities until conditions set by the user are met, and then releases the Entities in one batch. The Entities emerge as a single unit, but retain their individual Entity identification.

· Unbatch. Separates a batched Entity into its constituent parts (Entities).

· Split. Divides an Entity into parent and child Entities that can undergo parallel processing.

· Join. Reunites families of Entities that were created in Split Activities

· Transform. Transforms an arriving Entity into a different Entity type, and releases one or more Entities of the new type.

· Transfer. Routes an entity from one model layout to another model layout without using a connector.

· Clone. Makes duplicate copies of Entities.

· Gate. Accumulates Entities until a condition is met and then releases a specified number of them.

· Assign. Assigns values to global Entity and Model Attributes and sets Entity priorities.

· Synchronize. Coordinates the release of various Entities.

Resource Related

Unlike other SIMPROCESS Activities, these Activities affect Resources, not Entities:

· Replenish Resource. Adds capacity to consumable Resources.

· Get Resource. Obtains a Resource and holds on to it across several Processes and Activities.

· Free Resource. Releases Resources obtained by Get Resource Activities.

Resource-related Activities are described in Chapter 5, "Resource Modeling Constructs," beginning on page 147. The Entity-Related Activities are covered in this chapter.

Entity-Related Activities

Activities that are used to coordinate grouping of Entities are addressed here. The type of coordination to be done is specified at the Activity. Entities are queued up in these Activities (except for Unbatch and Split) until the conditions are met. This queueing time is reported as "Hold for Condition" in the reports. This is reported separately from the "Wait for Resource" queueing time which can accumulate at any Activity for which a Resource requirement has been specified.

· Assemble Activity

· Batch Activity

· Unbatch Activity

· Gate Activity

· Synchronize Activity

· Split Activity

· Join Activity

Assemble Activity

The Assemble Activity is used to build several Entities into a single output Entity. Consider a case where two approvals and a check are required to form one "approved loan." An Assemble Activity can be used to model this process.

Assemble has two input Pads (Component and Trigger) and two output Pads (Out and NoMatch) that determine Entity behavior. The Component Pad places incoming Entities into a queue until all Entities to be assembled have arrived. An Entity entering the Component Pad not on the component Entity list will immediately leave the Assemble Activity through the NoMatch Pad.

The Trigger Pad is only relevant if Hold for Trigger is selected as one of the Activity's options. Entities entering the Trigger Pad can trigger the release of the assembled Entities. Assembled Entities are only released when an Entity, such as a Customer Order, arrives at the Trigger Pad. The trigger can be released by using the FireTrigger System Method instead of having an Entity enter the Trigger Pad. The name of the Activity must be unique within the model for the system method to work properly. See "SIMPROCESS System Methods" on page 521.

Dialog Field Definitions

Rank Method sets the rank method of the queue for the Entities to be assembled. There is a separate queue for each component Entity type. The rank method is the same for all queues. The default is First In First Out. The rank methods are:

· First In First Out

· First In Last Out

· Earliest Created First

· Latest Created First

· Highest Priority Value First

· Lowest Priority Value First

· Highest Attribute Value First

· Lowest Attribute Value First

Selecting Highest Attribute Value First or Lowest Attribute Value First will cause the Attribute field to be active. Select the desired attribute from the list. If the selected attribute is a local Entity instance or Entity type attribute, a run time error will occur if an Entity enters that does not have the selected attribute defined.

Component Entities is a list of component Entities to be converted to assembled Entities. Entities on the list are queued until the specified quantity of each Entity type has entered the Assemble Activity.

· Add: Opens a dialog to define component Entities

· Edit: Opens a dialog to modify the component Entity definition

· Remove: Removes the selected component Entity

· Batch Components: When selected, the assembled Entity batches the component Entities. When not selected, component Entities are disposed when the assembled Entity is released.

· Hold for Trigger: Holds output Entities until an Entity enters the Trigger Pad.

Assembled Entity shows the Entity type to be released after all component Entities have entered the Activity. A combo box provides a list of defined Entity types.

Duration specifies the delay time of the Activity. The time set in the Duration will be applied after the Assembled Entity has been created. Thus, the Duration will be reflected in the Cycle Time of the Assembled Entity.

· Value: The amount of time required to perform this Activity. Use the combo box to select a statistical distribution or enter a constant value directly in this field.

· Units: Determines if the Duration entered is measured as nanoseconds, microseconds, milliseconds, seconds, minutes, hours, days, weeks, months, or years.

Batch Activity

The Batch Activity combines several Entities into one Entity while retaining the identities of the original Entities. The resultant Entity travels throughout the process as a single Entity. It can be disassembled into its constituent Entities using an Unbatch Activity at some later time.

The Batch Activity is useful when combining several Entities (e.g., merchandise ordered by various customers) into a parent Entity for transportation. After the transportation Activities, the parent Entity can be broken down into the Entities that comprised it. Statistics can be collected for the batched Entity separately from its constituent members.

Dialog Field Definitions

Batched Entity is the type of Entity that will serve as the container or parent Entity. An Entity of this type is created and all other Entities become children of the parent.

Quantity to Batch is the maximum number of Entities that fit in one batch.

Maximum Hold Time: is the maximum amount of time to hold before a batch that has met the Minimum Quantity requirement is released.

Minimum Quantity is the minimum number of Entities that must be in a batch before it can be released.

Duration is the time specified for a Batch Activity that will be applied after the Batched Entity has been created. It will be reflected in the Cycle Time of the Batched Entity.

Rank Method sets the rank method of the queue for the Entities to be batched. The default is First In First Out. The rank methods are:

· First In First Out

· First In Last Out

· Earliest Created First

· Latest Created First

· Highest Priority Value First

· Lowest Priority Value First

· Highest Attribute Value First

· Lowest Attribute Value First.

The Attribute field will be active if Highest Attribute Value First or Lowest Attribute Value First is selected. Select the desired attribute from the list. If the selected attribute is a local Entity instance or Entity type attribute, a run time error will occur if an Entity enters that does not have the selected attribute defined.

Unbatch Activity

An Unbatch Activity separates a batch Entity into its constituents (children) and then destroys (Disposes) the parent Entity. Many levels of batching are possible, i.e., batches can be composed of batches. The Unbatch Activity defaults to only disaggregate one level of batch at a time. Unbatch Nested Batches must be selected to disaggregate all levels.

The time specified in the Duration will be applied before the unbatching occurs. It will be reflected in the Cycle Time of the Batched Entity.

The Unbatch Activity defaults to disposing the Batched Entity that enters the Activity. Retain Batched Entity must be selected for the Batched Entity to not be disposed,. The Batched Entity will continue through the simulation with no child Entities.

Gate Activity

The Gate Activity accumulates Entities until some number of Entities have been received or until a signal is received to release Entities. It then sends a designated number of Entities out into the model. Entities can be batched in a Gate Activity.

A Gate Activity has two Pads that determine Entity behavior, the Hold Pad and the Trigger Pad. The Hold Pad, located on the lower left of the Gate icon, is a queue for incoming Entities. Entities that arrive at that Pad are stored here. The Trigger Pad, located on the upper left of the Gate icon, signals release of Entities.

A Gate Activity has two gating policies that can be effective concurrently. The first gating policy is called Trigger Release. An Entity is disposed of when it arrives at a Trigger Pad, and it triggers the release of the number of Entities as specified in the Trigger Release Quantity field. A Trigger Pad can synchronize the flow of Entities between different Activities.

The Gate Activity can be used as a buffer or queue to hold material from one section of the model until a condition is met in another part of the model. A Trigger Entity is sent to the Trigger Pad of the Gate Activity when that condition is met.

An example of this would be if customer orders are printed out and sent on to the shipping department on an hourly basis. This could be reflected in the model by a Gate Activity, which is triggered when it receives an Entity that is generated hourly by a Generate Activity.

The second gating policy is called Threshold Release. It allows the release of some number of Entities once a threshold number of Entities have arrived. This policy is useful, for example, in cases where a truck must wait until it is full before it departs.

Gating policies can be effective concurrently, so this Activity can implement a truck leaving when it is full or on the hour, even if it is not full.

Note that Entities can be released from Gate Activities using Expressions. See Chapter 10, "Customizing a Model with Attributes and Expressions," beginning on page 237 for information on Expressions. Also, see "Methods ReleaseEntity, Gate, GetEntity, EntityExists:," beginning on page 568.

Dialog Field Definitions

Batch Entities will batch the Entities before leaving the Activity.

Batched Entity is the type of Entity that will serve as the container or parent Entity. An Entity of this type is created, and all other Entities become children of the parent.

Rank Method sets the rank method of the queue for the Entities waiting at the Gate. The default is First In First Out. The rank methods are

· First In First Out

· First In Last Out

· Earliest Created First

· Latest Created First

· Highest Priority Value First

· Lowest Priority Value First

· Highest Attribute Value First

· Lowest Attribute Value First

The Attribute field will be active if Highest Attribute Value First or Lowest Attribute Value First is selected. Select the desired attribute from the list. If the selected attribute is a local Entity instance or Entity type attribute, a run-time error will occur if an Entity enters that does not have the selected attribute defined.

Threshold Release

· On/Off: Enables/disables the Threshold Release feature. Threshold Release is on when the check box is selected.

· Threshold Quantity: The threshold number of Entities to accumulate and release when the Threshold Release is checked on.

Trigger Release

· Release All: Releases all the accumulated Entities when a Trigger Entity has been received on the Trigger Pad.

· Quantity: The number of Entities to release when a Trigger Entity has been received on the Trigger Pad. This is used with the Trigger Release policy. The value can be a constant integer or can be derived from a statistical distribution.

The Trigger can be released by using the FireTrigger System Method instead of having an Entity enter the trigger Pad. The name of the Activity must be unique within the model for the system method to work properly. See "SIMPROCESS System Methods" on page 521.

Duration is the time specified for a Gate Activity that will be applied when the Entities are released. Each Entity released will have a duration, unless the Entities were batched. In that case there is only one duration for the Batched Entity.

Synchronize Activity

A Synchronize Activity coordinates the release of many Entities, which may be of various types. The number of input/output Pads for a Synchronize Activity is specified. Entities arriving at each Pad are stored in separate queues. Each queue releases one Entity to its corresponding output Pad when each queue has at least one Entity.

A project may require four jobs to be done in parallel, with the work kept in step at various tasks within the process. All others must be at the same stage of completion before work can proceed on one job. Synchronize Activity may be used with four Pads to model the wait time and release of the parallel tasks.

Dialog Field Definitions

Number of Pads is the number of pairs of input and output Pads required by this Activity.

Rank Method sets the rank method of the queues for each input Pad. Each queue will have the same rank method. The default is First In First Out. The rank methods are:

· First In First Out

· First In Last Out

· Earliest Created First

· Latest Created First

· Highest Priority Value First

· Lowest Priority Value First

· Highest Attribute Value First

· Lowest Attribute Value First

The Attribute field will be active if Highest Attribute Value First or Lowest Attribute Value First is selected. Select the desired attribute from the list. If the selected attribute is a local Entity instance or Entity type attribute, a run time error will occur if an Entity enters that does not have the selected attribute defined.

Duration is the time specified for a Synchronize Activity that will be applied to each Entity when the Entities are released.

Entity Control Activities

This section discusses Activities that are used in the control of Entities through the process model:

· Assign Activity

· Transform Activity

· Branch Activity

· Merge Activity

· Transfer Activity

· Clone Activity

Assign Activity

The Assign Activity is one method used to assign values to attributes. The Assign Activity can also be used to change the priority of an Entity.

The Assign Activity is covered in detail in "Assign Activity," beginning on page 250.

Dialog Field Definitions and Buttons

Set Entity Priority sets or changes the Priority of an Entity. The priority defaults to None, which means the Entity priority is not changed. Entity priority must be within the range 1 to 100. If a value less than 1 is returned from the distribution, then the Entity priority is not changed. If a value greater than 100 is returned from the distribution, then a warning is displayed, and the Entity priority is set to 100.

NOTE: Entities with a higher priority use available Resources first.

Set Attributes lists existing attribute assignments:

· Use Add... to set values for Entity attributes.

· Use Edit... to modify existing assignments. Select the attribute assignment you want to modify from the Set Attributes list.

· Use Remove to delete a previously defined assignment.

Duration is used as in other SIMPROCESS Activities.

Transform Activity

The Transform Activity changes one type of Entity into another type. A single arriving Entity can be changed into many output Entities (all of the same type.)

Dialog Field Definitions and Buttons

Output Entities

· Quantity is the number of new Entities to create. This number of each Entity arriving will be generated for every Connector exiting the Activity.

· Entity Type is the type of Entity to be released. Select the type from the pull-down list.

· The time specified in the Duration will be applied before the transform occurs, thus it will be reflected in the Cycle Time of the incoming Entities. The outgoing Entities will not have accrued any Cycle Time.

Copy Attributes tab is where attributes of the arriving Entity can be selected to be transferred to the new output Entity. Examples of attributes that can be copied include User Defined Attribute values, creation time, etc. Time Stamps and Entity Priority can also be copied.

Specifying Attributes to Copy

Selecting the Copy Attributes tab displays the following:

The following options on the Copy Entity Fields and Attributes tab can be selected:

· Copy Creation Time copies the simulation creation time of the original Entity to the transformed Entities.

· Copy Time Stamps applies the list of predefined timestamps carried by the arriving Entity to transformed Entities.

· Copy Entity Priority applies the priority of the arriving Entity to transformed Entities.

The transformed Entity receives the default Priority value defined in the Entity Type unless it is copied.

User Defined Entity Attribute values associated with the incoming Entity may also be copied. During simulation, different variable types (Integer, Real, Boolean, and String) can be added to an Entity.

Click on OK when finished to leave the dialog, confirming your current selections. The Cancel button cancels the current dialog selections.

Branch Activity

A Branch Activity routes Entities to different paths of the process model. It allows modelling decision processes, with alternative pathways selected depending on the result.

In the Branch Activity detail dialog, you select the type of branching criteria to use: Probability, Entity Type, Attribute value, or Priority. The precise criteria are specified on the Connectors associated with the Branch.

Consider the case where the order fulfillment process for new customers requires a step that is not needed for repeat customers, such as creating a customer profile. Use different Entities for new customers and repeat customers and branch on Entity Type.

Or use a single Customer Order Entity and assume that a certain percentage of customers are new and a certain percentage are repeats. Select Branch Type Probability and then set the probability of each event on the Connectors leading from the Branch output Pad:

Dialog Field Definitions and Buttons

Select Branch Type

· Probability. Entities routed based on a probability specified on each Connector leading from the Branch. All probabilities must sum to 1.0, or one of the Connector's should have the Otherwise field set to True. Stream is the random number stream to use for the probabilities.

· Attribute. Route Entities to the appropriate Connector based on values of User Defined Attributes or System Attributes. (See "Using Attributes in SIMPROCESS," beginning on page 241 for more information on User Defined and System Attributes.)

· Entity Type. Route Entities based on type, e.g., send Orders one way and Bills another. Set the Entity Type on the Connectors emanating from the Branch.

· Priority. Ability to route higher priority items on one path, lower on another. The priorities are specified on the Connectors.

Branch Connectors

Connectors link Activities and Processes together. Connector names can assist in labeling a model, e.g., the Entity type that flows. SIMPROCESS will automatically label Connectors emanating from Branch Activities. (See "Connectors and Branch Activities" on page 135 for details.)

The Branch Connector Properties dialog contains the Name of the Connector, Comment, the Line Width and Line Style, Branching Parameters, Duration, Collect Connector Statistics, and Collect Connector by Entity Statistics.

To display the Connector Properties, either double-click on the Connector, right click on the Connector and choose Properties, click to select the Connector and click the Properties button on the tool bar, or click to select the Connector and choose Properties on the Edit pull-down menu.

Connector Names

A default Connector name, e.g., Conn44 is assigned. To change the Connector Name, edit the Name field in the Connector properties. The AutoLabel check box is discussed below.

Displaying Connector Names

The Edit Preferences option, on the Edit pull-down menu, determines if Connector names are displayed in the model. However, individual Connector dialogs have Show Name check boxes that will override the model default.

The Name field is displayed across the middle of the Connector if Show Name is selected.

The Auto Label check box applies only to Connectors from Branch Activities. The Name will be generated by SIMPROCESS. SIMPROCESS uses entries in the Connector Detail dialog box depending on the Entity Type.

Connectors and Branch Activities

There are additional fields that appear in the Connector detail dialog box when the Connector is connecting a Branch Activity to another Activity or Process. When a Connector emanates from a Branch Activity, use the Branch Connector Properties dialog box to specify the branching parameters.

The corresponding Connector Properties are based on the type of Branch selected in the Branch Activity Properties dialog.

Entity Type - Select the type of the Entities that should flow along this Connector from the combo box.

Probability - Enter the probability (a number between 0 and 1.0) that the Entity will flow on this Connector.

Priority - Enter the Entity priority number to branch on. Values are from 1 to 100.

Attribute - The first line shows the name of the Attribute selected in the Branch Properties box. Branching can be based on the equality of numbers, strings, booleans, or on ranges of numbers. If the selected Attribute is a local Entity instance or Entity Type attribute, a run time error will occur if an Entity enters that does not have the selected Attribute defined.

Otherwise - If Otherwise is selected, this Connector becomes the default branching Connector. This means all Entities pass through this Connector if none of the criteria in any other Connectors are satisfied.

Branch Activity Type	Connector Properties Used	Display Example
Probability	Probability (between 0 and 1.0) Otherwise (True or False)	0.75 Otherwise
Attribute	Branch If Attribute Is (value) Otherwise, (True or False)	Displays User Defined Attribute Name on Connector with IF or AND conditions, e.g. My Attr1 = 5, or 4 < My Attr1 < 7 Otherwise
Entity Type	Type (from Entity type combo box) Otherwise (True or False)	Request for Quote Otherwise
Priority	Priority (Entity Priority 1-100) Otherwise (True or False)	1 Otherwise

Merge Activity

A Merge Activity routes Entities from different Connectors into one Connector. Merge can be used to TimeStamp all Entities or to reduce the number of "to and from" Connectors to create a more visually appealing model. Also, a Merge Activity is useful if groups of Activities will be copied and pasted. By using a Merge Activity, Connectors are not lost during the copy and paste.

Transfer Activity

A Transfer Activity routes entities without the use of a Connector. Entities can be routed within the same model (Local) or to other models (Remote) with theTransfer Activity. (NOTE: Although, the Remote capability is discussed, this capability has not yet been implemented.) The Transfer Type for a Transfer activity can be Send or Receive. A sender routes entities to a receiver. Thus, Transfer Activities should be used in pairs. Every sender should have an associated receiver. A sender can only connect with one receiver, but a receiver can have multiple senders connected to it. Each Transfer Type designates a Connection Type of Local or Remote. Local means the entity transfer will occur within the same model. A Send Transfer Activity that is designated Local can only connect with a Receive Transfer Activity in the same model that has also been designated Local. Remote means the entity transfer will occur between models. A Send Transfer Activity designated Remote can only connect with a Receive Transfer Activity in a different model that is also designated Remote.

When the activity is placed on the layout, it does not have an input pad or output pad. Selecting Send causes an input pad to be added to the activity. Selecting Receive causes an output pad to be added to the activity. Once the combination of Send or Receive and Local or Remote has been set, it cannot be changed. The activity must be deleted and recreated if either option needs changing. The default combination for a new Transfer Activity is Send and Local.

Dialog Field and Button Definitions

Transfer Type sets the Transfer Activity as Send or Receive. Both Send and Receive have a Connection Type (Local or Remote). The Connection Type options enable based on the selection of Send or Receive.

Connection Type sets the Transfer Activity as Local or Remote. The Local option has a Connection button associated with it, and the Remote option has a Protocol button associated with it. The Connection button is active when Local is selected, and the Protocol button is active when Remote is selected.

The Connection button for the Send option operates differently from the Connection button for the Receive option. Clicking the Connection button associated with Send/Local brings up a modified version of the Activity Browser dialog. (See "Activity Browser..." on page 35 for more information on using the Activity Browser.) This version includes a Cancel button.

All the functions of the dialog are the same as the Activity Browser dialog. Select the receiving Transfer Activity. (The Find Activity/Process section of the dialog can be used to search for Transfer activities.) The activity selected when Close is clicked must be a Transfer Activity with Receive and Local selected. An error will occur if the activity selected is not a Transfer activity with Receive and Local selected. Click Cancel to not make a selection or to keep the current selection. Although the selection of Send or Receive and Local or Remote cannot be changed once selected, the Connection can be changed once set.

The Connection button associated with the Receive option displays a list of the Send Transfer Activities routing entities to that Receive Transfer Activity. No editing of the connections is allowed. The dialog is for informational purposes only.

The Protocol buttons will set the sending and receiving protocols for Remote transfers when the Remote capability is implemented.

Clone Activity

The Clone Activity generates duplicate Entities. Note that this activity is only available from the Create menu. This is because the Clone activity exists primarily to support pre-SIMPROCESS version 4.0 models. Since the cloned entities leaving the Clone activity are of the same type as the entity entering the activity, the entity statistics for the type of the entering activity are affected by the creation of the cloned entities. The entity statistics are skewed by the Clone activity. The Split activity is the recommended activity for entity cloning since the cloned entity can be a different type of entity. Thus the statistics for the original entity are not affected by the creation of cloned entities.

Dialog Field Definitions

· Number of Copies per Connector is the number of Entities that will come out the Clones Pad into each Connector.

· If a Duration is defined for the Activity, the time specified in the Duration will be applied before the cloned Entities are created. In other words, it will be reflected in the Cycle Time of the incoming Entities.

· If Time Stamps are defined for the incoming Entity, those values can be passed to the Clones by selecting Copy Time Stamps.

Split and Join Activities

The Split and Join Activities work together to temporarily split the processing of an Entity among parallel Activities.

At the Split Activity, an Entity is converted into two or more Entities, each of which follows a different path before (optionally) reuniting at a Join Activity.

The Split Activity generates child Entities from the parent Entity. The children and the parent Entity belong to the same family. After going their separate ways, the family is reunited at the Join Activity, where a single Entity, the parent, exits for continued processing.

In the order fulfillment process, Split and Join might come into play in the handling of rush orders. To speed up processing of rush orders, the work might be divided among several clerks at some point:

The figure above shows how a Split Activity takes a customer order Entity and releases three Entities, the original and two children (or clones). Each Entity goes to a different Activity, where a different task is performed on the order.

Defining a Split Activity

When you add a Split Activity to the SIMPROCESS layout, it has one input Pad and two output Pads attached:

The upper output Pad is named Clones; the lower Pad is named Original (if you double-click on the Pads, you will see their names in the Pad Detail dialog).

Use the Original Pad to route the original Entity to the next Activity in its path. Use the Clones Pad to route each of the split Entities to their next Activities. An unlimited number of split Entities of different Entity types can be released at a Split Activity, but all Entities emerge from the same Pad.

Dialog Field Definitions

The unique attribute of the Split Activity is:

Family Name. This names the family of Entities being created. The original Entity and its children can be identified by their common family name. Family Name is used at a Join Activity to identify the Entities to be joined. Family names must be unique within a model.

Identifying Split Entities

Split Entities are Attributes of the Connector: a Split Entity is defined for each Connector linking a Split Activity to a connecting Activity.

A single Connector is drawn from the Original output Pad to an adjoining Activity's input Pad. Then, the Split output Pad is connected to the other adjoining Activities.

As an example, the figure below shows the distribution of rush order processing into three simultaneous Activities: paper work, retrieval of an item from inventory, and updating of the inventory database.

The Original Pad of the Split Activity is connected to the input Pad of the Update Database Activity, so the original customer order Entity flows through Update Database.

Double-clicking on one of the Connectors emanating from the Split Pad opens the Split Connector properties.

Dialog Field Definitions

The unique attributes of the Split Connector are:

· Entity Type is the field where the Split Entity type that will flow along this Connector is selected.

· Quantity specifies how many of the split Entities will flow along this Connector for each original Entity that enters the Split Activity.

· Copy Attributes opens a dialog where Global Entity Instance attributes to copy from the original Entity to each of the Split Entities are selected. Entity Priority and Time Stamps can also be copied from the original Entity to each of the Split Entities.

· New Entity button opens the Entity definition dialog for modifying Entity-type definitions.

Clicking on the Entity Type pull-down box displays a list of the Entities in the model. The Entity to flow along this Connector is selected here.

For analysis purposes, consider using a different name for the children. For example, if the original Entity type Customer Order is used for each of the paths leading from the Split Activity, distortions in the statistics for the Customer Order Entity could occur. When all split Entities meet again at the Join Activity, the two split Entities are destroyed at the Join, while the original Entity continues on. When total cycle time for Customer Order Entities is calculated at the end of a simulation, those split Entities skew the statistics.

Cycle times for the split Entities are measured from generation in the Split Activity to termination in the Join Activity, while the original Entity's cycle is measured from a Generate to a Dispose Activity.

An Entity named Temp is defined and used on the Split Connectors in the case of Rush Order Processing in order not to skew the cycle time or Entity count statistics for Customer Order Entities.

Note that using an Entity named Temp for split Entities is adequate if the simulation statistics of these Entities is not important. Define a different Entity type for each Split path if the number of each split Entity generated during a simulation is important, or any other Entity statistic is important.

Select the Auto Label option if you want SIMPROCESS to display the Entity name on the Connector. The name will be displayed unless Show Name on the Connector is turned off.

Click on OK when you finish defining the Connector.

Defining a Join Activity

Entities released from a Split Activity are reunited at a Join Activity.

The Join Activity icon has one input Pad and two output Pads. The upper output Pad is named Join; after reuniting with their family, the original Entity exits through this Pad. The lower Pad is named NoMatch; Entities that are not members of the Join family leave through this Pad. An Entity that is not a member of the Rush Order family that enters the Join Activity will pass through the Join Activity and exit through the NoMatch Pad. Note that no processing time will apply even if a delay duration is specified.

Dialog Field Definitions

Family Name identifies the Entity family to be joined. The pull-down list for Family Name contains the names of all families that have been defined in the model. Family names do not have to be unique in Join Activities, i.e., two Join Activities could use the same family name. This would be done if the same split Entities needed to be joined twice. The exiting Entity could be a batch that could be later unbatched and joined again after further processing.

Batch Family Members tells SIMPROCESS to batch the child Entities with the original Entity. The Entity could be separated into its components at an Unbatch Activity. Otherwise, all the child Entities are disposed in the Join Activity. SIMPROCESS releases the original Entity through the Join Pad.

By default, All Family Members Required is not selected. When the original Entity enters a Dispose Activity or is otherwise destroyed before it reaches a Join, SIMPROCESS releases one of the child Entities at the Join Activity. Which child Entity is released cannot be specified; SIMPROCESS selects it.

Note that if any of the child Entities are disposed before they reach their Join Activity, the rest of the family still reunites at the Join; if the rest of the family is already at the Join Activity at the moment the child Entity is destroyed, SIMPROCESS processes and releases the original.

If All Family Members Required is selected, then no Join will occur until all family members (children and parent) arrive at the Join Activity. Thus, if any members of the family are disposed before the Join, then the remaining family members will remain queued in the Join Activity.

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