overall efficiency of economic activity are economic
efficiency, realized/planned performance, product
competitiveness, or company excellence.
The competitiveness of an enterprise is
determined by various factors that have a decisive
influence on the competitive power of the company,
such as production factors, managerial and
marketing capabilities, and financial, technical, and
creative resources.
The internal conditions available to an enterprise
contribute to its ability to obtain an advantage over
competitors, both in terms of costs and diversity,
quality, and renewal of the offer.
Any enterprise is made up of manufacturing
sections which, in turn, are divided into workshops.
This structure forms the manufacturing system of an
enterprise. Structurally, the workshop is made up of
independent manufacturing machines. To order a
product, manufacturing machines are grouped in the
manufacturing system specific to the product.
In industry, the manufacturing operations on
CNC machines (machine tools with numerical
control) allow controllable processing times, [4]. For
example, for a CNC turning machine, there is a
nonlinear relationship between the cost of the
manufacturing and the time of required processing,
[7]. The simultaneous objectives on a single CNC
machine are considered total manufacturing cost
(F1) and total weighted completion time (F2). Also,
the decisions for processing time are as critical as
decisions for job sequencing. F1 subject to a given
F2 level, is given an effective model for the problem
of minimizing. For this problem, in [7], it is deduced
some optimality properties and then, it is proposed a
heuristic algorithm to generate an approximate set of
efficient solutions.
In [8], the authors show that they can generate
alternative reactive schedules considering the
manufacturing cost implications in response to
disruptions if they have the flexibility to control the
processing times of the jobs. They consider that
processing times of the jobs are compressible at a
certain manufacturing cost which are represented
with a convex function of the compression on the
processing time in a non-identical parallel
machining environment. By reassigning the jobs to
the machines and compressing their processing
times, in rescheduling, it is highly desirable to catch
up with the original schedule as soon as possible.
3 Economic Modelling Method
Proposed
Currently, the machines of manufacturing systems
are controlled by the programs of the machine tools
with the program command that composes the
system, [10]. Management is exclusively technical,
because there is no economic variable, although this
would represent the final goal of the processing
processes. The dynamics of the changes and the
general progress of the society are translated at the
company level through orders many in number,
small in volume, very varied, obtained through
frequent auctions with answers in short terms, which
do not provide time for the pertinent analysis of the
orders. As a result, it is no longer possible to manage
in the long term. A fluctuating type of management
(just like the market), online, with prompt, quick
reaction, but still ephemeral, must be imposed.
The manufacturing system receives contracts
following auctions (competitions) generated by
market requests. Obtaining maximum
competitiveness through instructions and
intervention on how to develop the manufacturing
process. The evaluation of competitiveness generates
a competitive management system. This competitive
management must enable the development of
competitive offers that will enter the auction. This is
done by using two learning techniques:
reinforcement learning technique to learn about the
market and unsupervised learning technique to learn
about the manufacturing system.
3.1 Modeling Algorithm
Starting from the contractual specifications, based on
the monitoring of the operation of the technological
systems, the consumption and costs of the
technological operations are established. A set of
data is formed and, through data-mining, the process
of discovering relationships and combinations,
generally knowledge, is carried out, and the results
found can be included in an automatic decision
support system.
The data mining methods that will be used are
unsupervised learning and supervised learning.
Through unsupervised learning, using the Principal
Components Analysis (PCA) technique, the pattern
of state variables of technological systems will be
discovered. According to the causal relationships
between variables, they are grouped using the
Cluster Analysis (CA) technique through
unsupervised learning. For each group of variables,
through supervised learning, knowing the data, on
the one hand, regarding the dimensions of the part,
the working regime, the precision characteristics,
and, on the other hand, those regarding the
consumption of time, materials, energy, the model
will be built econometric of the manufacturing
system. For example, cost and productivity could be
WSEAS TRANSACTIONS on ADVANCES in ENGINEERING EDUCATION
DOI: 10.37394/232010.2024.21.4
Daschievici Luiza, Ghelase Daniela