They can only be started when their required resources are available. resource pools for defining the available resources.resource roles (with resource cardinality constraints) for defining the required (and admissible) resources, and.Resource-constrained activities are modeled by means of They are composed of a start event and an end event. In DPMN, activities are composite events with some duration. A Resource-Dependent Activity Scheduling arrow, like the one between go to loading site and load activities, means that as soon as an activity of the preceeding activity type has been completed, a new planned activity is added to the queue of planned activities of the succeeding type (and started as soon as all required resources are available).In our example model, this means that one request event is followed by multiple go to loading site activities, one for each truck and each wheel loader assigned to the job. A Multiple Events Scheduling arrow, like the one between requests and go to loading site, means that one instance of the preceeding event type triggers multiple instances of the succeeding event type.Event Scheduling arrows are not part of BPMN, rather they have been proposed by Schruben (1983) for Event Graphs. An Event Scheduling arrow, like the one between load and haul, has the meaning that the succeeding activity is started as soon as the preceeding activity has been completed (there is no need for enqueing a planned activity, since all resources required by the succeeding activity are provided by the preceeding activity).This is described by the following conceptual DPMN process model: The activities haul, dump and go back to loading site are performed by a truck as their only resource, while load activities require both a truck and a wheel loader (with the latter one being the performer). The activities go to loading site and go home have a truck or a wheel loader as their performer, which is generally a special resource of any activity. either go back to loading site, if the job is not yet done, or else go home.The Load-Haul-Dump process can be described as the following sequence of activities: The company has two resource pools: one for trucks and one for wheel loaders. The Load-Haul-Dump ProcessĪ haul service company accepts requests for hauling large quantities of earth from a loading site to a dump site, using dump trucks and wheel loaders.
DPMN can be regarded as a solution to this problem.
It has been an open problem for more than 10 years, if and how BPMN process models can be aligned with the PN paradigm and the Seize-Delay-Release modeling pattern used by all Discrete Event Simulation (DES) software packages, including AnyLogic. My efforts are going to result in the forthcoming book Discrete Event Simulation Engineering with DPMN, OESjs, Simio and AnyLogic, which is already available as a draft.Īs opposed to business process modeling with activity-based flowchart languages like BPMN, process modeling with AnyLogic is based on the Processing Networks (PN) paradigm and the Seize-Delay-Release pattern for modeling resource-constrained activities introduced by the simulation language GPSS (Gordon, 1961). I'm using this (modeling and article writing) project for learning two of the leading Discrete Event Simulation (DES) tools, Simio and AnyLogic, to understand their process modeling concepts, and for comparing their DES approaches with the business process modeling approach of BPMN.
The first part of this article series is AnyLogic Process Models and BPMN&DPMN – Part 1: Pizza Service. In these articles, I will discuss example models like Load-Haul-Dump, Pizza-Delivery, or Diagnostic-Clinic, presented in the book The Art of Process-Centric Modeling with AnyLogic by Arash Mahdavi.
This is the second part of a series of articles on on how to design AnyLogic process models with BPMN and DPMN, the Discrete Event Process Modeling Notation that I have developed as an extension of Event Graphs by adding elements from BPMN.