Activity Modeling Constructs

Activity modeling constructs are the objects at the lowest level of the SIMPROCESS hierarchy and they are used for modeling the behavior of a process. Activities are non-decomposable. The SIMPROCESS Model Toolbar contains 19 built-in activity blocks; however, re-usable activity templates can be created and added to the Library Toolbar. Below is a basic overview of the SIMPROCESS activity modeling constructs.


A GENERATE activity generates the arrival of entities into the model. Arrivals may be random, deterministic or conditional. An example of a GENERATE activity is the arrival of patients in a clinic. A GENERATE activity may have values for arrival time, quantity, frequency and occurrences.


A DISPOSE activity disposes of the entities when they are finished with processing. A DISPOSE activity can be used for collecting customized statistics for throughput or throughput time.


A DELAY activity defines value added or non value added activity times. It is one of the most commonly used activities in SIMPROCESS. A DELAY activity with resource constraints provides queue statistics that can be used for analyzing wait times.



An ASSEMBLE activity assembles multiple entities coming from multiple sources to create a single entity. For example, the development of a business proposal may contain three documents that are merged using an assembly activity.


A BRANCH activity allows for defining alternative routings for flow objects. Branching may be based on a probability or a condition. For example, the outcome of an inspection process may be modeled using probabilistic branching.


A MERGE activity provides a mechanism for merging a number of connectors into a single connector.


A BATCH activity combines a given quantity of entities into a single batch. An example of a batching activity is the accumulation of mail for delivery.


An UNBATCH activity splits a previously batched entity into individual entities. For example, unloading of a truck that results in multiple loads may be modeled with an unbatch activity.


A SPLIT activity takes an incoming entity and creates clones of that entity as well as providing an output of the original entity. For example, clones of a purchase order may be created with a SPLIT activity and sent to accounts payable and shipping.


A JOIN activity takes the clones and original entity that were split up, and matches them to produce the original one. For example, a JOIN activity may be used for matching the paperwork with the shipment.


A TRANSFORM activity converts an incoming entity into another entity. For example, a prospective buyer is transformed into a customer when an order is placed. This activity can be modeled using the transform construct.


A TRANSFER activity routes entities from one portion of a model to another without using a connector or routes entities to another model.


A CLONE activity makes multiple copies of the original entity. Note that this activity is not on the Model Toolbar. It is only on the Create menu in order to support pre-SIMPROCESS version 4 models.


A GATE activity holds entities in a queue, until a signal is received. For example, a GATE activity would be used to model orders held in inventory until a signal is received from the distributor to fulfill the demand.


An ASSIGN activity provides a mechanism for defining or changing attributes values.


A SYNCHRONIZE activity takes inputs that arrive at different times and outputs them in a synchronized fashion. For example, passengers and their baggage must be synchronized at a terminal.

Replenish Resource

This activity allows for replenishment of consumable resources.

Get Resource

This activity provides a mechanism for capturing resources that may be used for a number of downstream activities.

Free Resource

This activity provides a mechanism for releasing resources that were captured by a GET RESOURCE activity.