tools based on the principle of separating the planning
logic and describing the domain area of the specific
problem to be solved.
Such an approach should make it possible to tune
the system to the field of application, describing the
enterprise model in a formalized way as an object of
planning with the help of a basic set of concepts and
relations of the domain ontology. Further, this
formalized description, which is an ontological model
of the management object (technical object or
production enterprise), will be uploaded into the
planning MAS for constructing a plan and its further
adaptive adjustment based on events. In this case,
each order or resource will be associated with its own
software agent and a variant of its behavior, which
will be adjusted to the specifics of its owner from the
knowledge base that describes, for example,
qualifications of a worker or specific features of a
technological process.
The knowledge base is used for accumulation and
formalization in planning of those knowledge quanta,
the storage of which in corporate systems is currently
not provided. Such a knowledge base that already
contains instances of objects instead of classes can be
built based on the domain ontology in the form of a
semantic network of classes of concepts and relations.
The scheduling tasks have similar features,
highlighting which, we can create a basis of concepts
and relations sufficient to describe objectives,
preferences and limitations of system agents.
Thus, any work plan of an enterprise is built on
the basis of orders put into production, each of which
is characterized by applicable technological or
business processes, preconditions for starting task
implementation and the expected result (product or
service) for each task, as well as resource preferences,
and time standards for performing the work.
The planning task consists in calculating the
schedule for executing orders, which determines
distribution of resources by tasks and the exact time
of their fulfillment from the point of view of the
following performance indicators:
• fulfillment of orders as early as possible or in
time;
• increasing resource utilization;
• minimizing the average or maximum delays for
orders, etc.
The resulting solution must satisfy the
performance and resource schedule limitations. For
example, an unshared resource can be used by only
one operation at a time. If there are several valid
schedule options, it is necessary to choose the one that
is closest to optimal, since due to dimension of the
solution space or completely different criteria used at
different stages of planning, obtaining the optimal
result can be difficult and unjustified in terms of the
time spent.
Compared to the well-known and closest tasks of
constructing a schedule for Project Scheduling and
Job Shop Scheduling for machines (Shoham, Y.,
2009), the described problem statement has a number
of additional requirements, the most important of
which is growth of the number of individual criteria,
preferences and restrictions for each object, as well as
the need for adaptive schedule recalculation due to
events that change both availability of resources and
materials, and technological processes for execution
of orders.
3.2 Overview of Existing Ontologies of
Production Resources
Creation of ontologies for managing production
resources has been the subject of a number of studies.
One of the first known production ontologies was
the Process Specification Language (PSL) ontology,
which was developed as an independent language of
knowledge representation about the production
process and used for integration of various
applications (Gruninger, M., 2003).
In 2006, the Manufacturing’s Semantics Ontology
(MASON) was published, designed to simulate the
production process and calculate costs associated
with it. The main classes of concepts in it were
resources (including materials and personnel) and
operations (Lemaignan, S., 2006).
Borgo and Leitao (Borgo, S., 2007) proposed their
version of production ontology based on one of the
top-level public ontologies (DOLCE) and expanding
it with domain-dependent concepts. The resulting
ontology determines taxonomy of products and
components, materials, orders, and production
processes.
In the paper (Cândido, G., 2007), the authors were
among the first ones to use the ontological approach
for automating the assembly line management
process, creating a MAS in which resource agents
registered their capabilities in the system, while
agents of processes selected the necessary resources.
Advantages of using ontologies in agent-based
resource management systems have been
demonstrated in (Vrba, P., 2009). The described
ontology focuses on such concepts as order, product,
production process and enterprise structure (grouping
of equipment into production cells, description of
product movement routes between cells).