Conceptual modeling with processes

Abstract

Western philosophy of science has been heavily influenced by the idea that substantials are the main carriers of knowledge. Objects and their attributes and their relations to other objects dominate the world of knowledge representation. Processes play a subordinated role as they are merely seen as the things that create, change, or destroy objects. A recent study has shown that this view is dominant in modeling and simulation as well. The paper presents the (semi-) formal method developed in the doctoral study and its application to conceptual modeling techniques as they are taught in M&S education. The result shows that objects and relations are well captured, but that processes can be used as an alternative viewpoint as well. Using a process driven viewpoint opens new conceptual insights. We show that using the formal method allows to extend legacy conceptual methods to address these new aspects as well. INTRODUCTIONComputer simulations are programs and as such they are influenced by computer engineering methods and tools. Due to their discrete nature, digital computers are closely connected with the idea of finite state machine, which are abstracts machines that can be in one of several finite states. In order to change the state, an event occurs that changes the states. Several useful modeling techniques have been developed in the recent years, and we will have a look at a selected subset in this paper, but we will also show that the entity or the state machine or the substantial is in the canter of all these methods while the events or processes always play a secondary role: the state is, the process or event only exist to change the state. This idea is deeply rooted in Western philosophy, going back Plato and to Aristotle (350BC). In their philosophy, they postulated that substantials are the essence of what is real. What is can be described by properties and relations. As properties and relations can change, processes can be associated with such changes, but a process that doesn't change anything is meaningless. A process can also not create something out of nothing. Processes are agents of change, and the substantials are what are changed, and ultimately substantials are describing what is real. Reality is captured in matter and as such timeless. Processes change matter, but not reality. Aristotle used these basic ideas to constitute the beginnings of classification schemes to categories things and applying scientific methods to gain new knowledge. Ontology describes things and properties and how they are related. Substance has primacy over processes.Only recently, the possibility to look at substantials and processes as different sides of the same coin has been discussed. Process philosophy states that processes have primacy over substantials, as a current stat is just a configuration of the underlying process, and while the processes endure, the substantials are changed by them (Rescher 1996).The perspective of processes having primacy over substance allows for many interesting new perspectives, often ...

Representing the characteristics of modeled processes

“…As presented earlier (Tolk and Turnitsa 2012) (Turnitsa 2012) it is beneficial for a model to have not only components representing the various functional elements of the system it is representing, but also to have defining qualities to explain the differences among, and parameterization of those components. As shown in the earlier works, this is in alignment with (Sowa 2000), showing that the activities in a system model are worth identity and representation on an equal basis with the objects and states in a model.…”

“…Those other two components are the object and the relation. Both of these, as part of OPR method, were introduced to WSC in 2012 (Tolk and Turnitsa 2012).…”

“…Processes, the second component in the method, is the subject of this paper, and its predecessor (Tolk and Turnitsa 2012). As the paper itself is dedicated to the definition of processes for modeling, the only succinct definition given here is that process components, while also retaining identity and definition (as with objects), in addition are each responsible for some change to one or more components in the model.…”

“…It can be whatever the system is intended to perform "work" on, or it can be elements of the system itself, or perhaps just the passage of time -but if a system is dynamic, then something changes. The modeling of systems, including dynamic systems, has been shown (Tolk and Turnitsa 2012) to be most effective when it is based on an understanding of what the system is composed of, and a representation of that composition. With a dynamic system, this has been shown to include a representation of what is changing, and also the means for bringing about that change.…”

“…They are presented here, in order to contribute to the broader study of the theory of modeling, as considerations on the topic. This work follows on the work from WSC 2012 (Tolk and Turnitsa 2012) that established the need for such a system of representation by component description, and this represents the more in depth presentation of the work on the process component from the Object-Process-Relation (OPR) method. The method itself is not presented here in detail, but a brief overview of the three components (objects, processes, and relations) are described below (2.2).…”