Comparison of the subject-event approach with existing BPM systems

    The method of analysis and data fixation described in the text “ Subject-event approach to modeling complex systems ” is primarily intended for modeling business systems. The closest in name and, of course, in content to the proposed subject-event approach should be recognized two methods for describing business systems: EPC diagrams (event-driven process chain, event chain of processes) and a subject-oriented approach (s-BPM) of a company Metasonic. Let's try to make a comparative analysis of these enterprise modeling methods.

    EPC Charts


    The subject-event approach diverges from the EPC already at the level of definition of the concept of “event”. In EPC, an event is considered to be a state fixed at the input or output of a certain function and set by a set of certain parameters at some point in time. Although intuitively such a definition of an event seems quite understandable, in the general case it contains a large moment of uncertainty: what state are we talking about? the whole system? some object? subject? On the other hand, many events that clearly affect the course of the business process do not fall into this definition: EPCs include logical connectors, logical relationships, information flows, and other elements that are not described as events, although, in fact, they are.

    A significant advantage of the subject-event approach is the elimination of the multiplicity of types of connections in modeling (control flow, message flow, logical connections, associations, etc.) - all connections are considered exclusively as causal (logical) connections between events. Of course, one chain of related events can be designated as a process of changing a resource, another as a process of management, a third as a performance of a function by a subject, but in the original record all these processes are nothing more than flows of standardly described events connected through execution conditions.

    So, EPC diagrams from the perspective of the subject-event approach should be considered as a convenient and visual form of representing a fragment of an enterprise’s activity, reflecting the sequence of performing a number of functions by one or more single-level entities. Existing diagrams can serve as a data source for the formation of the event flow of an enterprise.

    Subject Oriented Approach (s-BPM)


    From the point of view of developing tools for modeling business processes, the subject-event approach should be considered as the next step after s-BPM. While retaining all the advantages of the latter, the subject-event approach has an important advantage in the form of a unification of the description of subjects and objects. Due to this, the maximum approximation of three aspects of the functioning of the enterprise is ensured: (1) direct activity, (2) its modeling and (3) data handling. In the event stream in one format, both the structure of the enterprise (the relationship between all its elements) and a complete description of all elements (both subjects and objects) are simultaneously recorded.

    The basis of s-BPM is the acts (events) of relations between subjects to which the functioning of the enterprise is reduced, or, more precisely, to the level of which its activities are projected. Moving further in this direction, the subject-event approach as a substantive element of the system suggests considering any act of the subject , all its relations with both subjects and objects, that is, any event that can affect the future state of the enterprise.

    The principle of describing an enterprise in s-BPM and in the subject-event approach are close - many subjects are taken and their relationships are fixed - but in the event approach, the subject is not considered as a system-forming factor. The subject is not intended to be described: like any object, it “emerges”, comes to light during the formation of the event flow as a certain set of events. The main question in the event approach is not “what is this subject doing here?”, But “which subject is performing this event and with which object?”. Attention shifts from a subject to an event, making the latter a fundamental invariant: several human subjects can be combined into one subject, or, conversely, one subject can be divided into several subjects, or even replaced with a program agent, also the object (resource) can be exchanged for another - and the event will remain the same. That is, the description of the enterprise itself through the stream of events is maximally adapted to modification and optimization, without changing the principles of data organization and the formats for their description.

    In response to the principle “process description with only five characters”, put forward by s-BPM, the subject-event approach offers its own: “description with just one character”. What principle follows from the understanding of the organism-enterprise as a stream of events: if we fix all the events, we get a full description of the whole system . And no additional entities.

    Although, of course, “one character” is only a slogan. The event flow of an enterprise in itself cannot be represented as a final modelas a logically isolated scheme with fixed notation. The event flow should be understood as a multidimensional universe of events, which for analysis should be considered from a specific point of view, projected onto a certain plane. Say, if we single out events at the level of “subject-subject” relations, we will get a subject-oriented description (s-BPM). If we fix the events of the beginning and end of a series of functions, we will have an EPC image of a fragment of the system. That is, from the position of the event approach, any of the existing schemes for describing business processes should be considered as a visualization method, as a projection of an organism-enterprise on one of the possible semantic planes. And there can be an infinite number of such projections.

    A significant advantage of the subject-event approach is that it does not offer a certain new scheme, the original model, but states that all existing schemes can, on the one hand, be reduced to the flow of events, and on the other hand, automatically distinguished from it by fixing some parameters , for example, the level of the subject, the movement of a resource, etc.

    conclusions


    1. Let us briefly repeat the basic principles of the subject-event approach:
    2. unification of the description at the lower level: there are only events, everything else - subjects, objects (resources, documents) are described as sets of events;
    3. combination of model and data - the event stream contains complete information about the system (description of objects and subjects, structure of the system);
    4. achievement of description relativity - any object exists only for the specified subject, is described through a variety of events, distinguishable by it;
    5. formalization of the level of description - subjects that distinguish the same objects are assigned to one level, the description has integrity at each level;
    6. coordination of descriptions at the highest level: all possible models (structural, functional, etc.) are reduced to a stream of elementary events that is common to them.

    At its core, the subject-event approach is not a method of organization, management, modernization, optimization, but only a universal platform for describing complex systems with time-distributed complexity. The choice of a particular management and optimization strategy can be proposed after a formal analysis of the structure of the system event flow. But even the fact of an event description without “hanging” any management and optimization strategies on it gives us, on the one hand, a tool for visualizing the system’s work at any levels and from the point of view of any subject, and on the other hand, formalizing all the regulations and tools for their quick modification. Indeed, this regulation is nothing more than a list of events carried out by a certain subject and conditionally related to other events.

    That is, one of the important advantages of the subject-event approach to the analysis of complex systems is the initial separation of the ontological description from management and optimization methods. The system appears before us at several levels:

    1. lower level of events containing complete information about the system;
    2. level of objects and subjects (which are represented as sets of events);
    3. the level of the hierarchy of event systems - processes, actions, activities and their relationship with objects and subjects;
    4. level of management and optimization, represented by schemes, models that reflect the structure of the enterprise from various points of view.

    Each level is ideologically and programmatically built on the lower one as a structure of the elements of the latter, but ontologically all structures at all levels consist of elements of the lower level (events), can be reduced to it. That is, ontologically (and programmatically) the events are not distinguished by levels, they are all elements of the event flow of the system.

    It should be especially noted that the subject-event approach in itself is only a tool for describing complex systems and does not directly determine any methods for optimizing and planning enterprises. (Although the very fact of modeling the event flow of a system can reveal problems in its organization and propose solutions to them.) However, it is the extremely unified and globally connected description that can be considered as the basis for the introduction and automation of any optimization and planning methods in real time.

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