Doctor of Technical
Sciences V.M. Kurganov
Tver State University,
Russia
Candidate of Technical
Sciences M.V. Gryaznov
Magnitogorsk State
Technical University named after of G.I. Nosov, Russia
Reservation in Providing of Automobile Transportation Reliability
Abstract
The definition of reliability and
failure of the transportation process in automobile transport is provided. It
is proposed to improve the reliability of the transportation process due to use
reservation. Types of reserves that are used to improve the reliability of
technical systems and the transportation process are compared. The approach to
optimization of the reserves of in automobile transport that is minimization of
total expenses for the reserves of material, technical and working resources, expenses
of forming functional reserves of management and expenses caused by consequences
from failures in transportation process is given.
Keywords:
Reliability, failure, transportation process,
reservation, redundancy of reserves, material resources, functional reserves of
the control, automobile transport.
Guaranteed accomplishment of treaty obligations and
getting profit from automobile transportation are impossible without high
automobile transportation reliability. Existing economical situation increases
the sensitivity of transportation process participants to failures in schemes
of cargo deliver and passengers. In cargo transportation even a small deviation
in time or cost of dispatch increases essentially probability of cancelling the contract for production delivery.
It will negatively reflect on economic activities of a seller and a consumer.
That is why recently more and more users of transportation service put in the
forefront the requirement to it’s guaranteed and reliable execution.
Reliability of
transportation process in automobile transport means a complex characteristic
which includes observance of the requirements transporting cargo quantity and
quality, safety of passengers and their luggage, timeliness of the delivering
objects, repairing of the set service level after a failure . This definition gives an opportunity of quantitative
reliability estimation through of infringement number the made by a transporter
transportation process options agreed with the customer. If one such an
infringement is associated with a failure, then reliability of the
transportation process can be defined as the ability of a transporter to
guarantee the quantity of failures on the set level.
Every autocarrier
should constantly work on decrease of failure quantity to the set level to keep
competitiveness. Reservation is one of the ways to increase reliability which
gives fast and significant effect in practice. According to the State Standard
27.002-89 “Industrial product dependability. General concepts. Terms and
definitions” reservation is the way to provide the object reliability by
attracting of additional resources and abilities which are superfluous in relation
to the minimal necessity of the required for the functions execution. Despite
the fact that concerns definition technical processes and systems in general it
can be used in transportation systems for the transportation process
reliability increase.
In technics the
problem of the object reliability increase can be solved by enlarged redundancy
of the reserves in its structure and redundancy of the requirements for the
production quality and exploitation. As a result the higher technical object
reliability level is the higher expenses for its manufacturing, repairing,
maintenance and exploitation. Improvement of the transportation process
reliability is largely based on the use of analogy in reservation of technical
objects – build excess reserves they hold. Two kinds of reserves can be
identified in transportation process. The first kind of reserves are obvious
reserves (by quantity or number) and latent reserves (by productivity) of material,
technical and working resources used in transportation process. Reserves of the
second kind are the functional reserves of control. Comparisation of kinds of
technical system and transportation process reserves are presented on (Fig.1).
Functional
reserves of control present the existence of additional functional abilities in
elements of transportation process providing the choice and switching of the
reserve working modes in unexpected situations during the transportation
process. Such kind of reserves often takes place in work of a transporter line
personal, e.g. when drivers work as forwarding agents, cashier-controllers,
loaders with the access to work on
cranes.
Fig. 1 - Kinds of the system (process) reserves
Functional
reserves of control are also involved in using of autodump truck with an
onboard platform which gives ability of the side or back unloading, in
exploitation of tractors with replaceable semitrailers for transportation of
different cargos, in equipping of cars with power supply systems working on
combined fuel and, in application of cars-self-loaders and in using of various
hinged equipment for increase of functional interchangeability of a rolling
stock.
The
transportation process reliability can be increased in such modes: reservation
(redundancy increase) of material,
technical and working resources in main and auxiliary operations of
transportation process; escalating of functional
reserves redundancy of steering by elements of transportation process (table).
Table – Reservation modes in maintenance of reliability of automobile
transportations
|
The mode name |
Features of
realization |
|
1.
Redundancy increase of material, technical and labour resources |
- Leads to growth of charges of reserves that negatively
affects cost of autotransportations; - There is no possibility of an operational administration
redundancy of reserves according to a casual stream of failures. |
End of the table
|
The mode name |
Features of
realization |
|
2.
Formation of functional reserves steering by elements of transportation
process redundancy |
- Allows to provide reliability of
autotransportations without an efficiency damage; - The methodical base of an estimation reserves size
on motor transport is not studied in details. |
Productivity of
the first mode is obvious - probability of manufacturing plan execution for
transportation with big reserves of quantity and productivity of a rolling
stock, work of drivers and repair personnel increases sharply. However this
mode is ineffective, as its realization is connected with increase in charges
of reserves that negatively affects transportations costs.
Increase of
transportation process reliability without an efficiency damage is possible
with escalating of "stocks" of functionality by its elements. By
increasing these stocks, it is possible to adjust non-failure operation of
transportation process in astable environment, without serious consequences
overcoming, for example, deviations in delivered fuel, breakage of loading equipment, seasonal falling of
demand for transportations, other crisis situations. The ways of formation and
escalating of functional reserves of steering are based on organizational
decisions and don't demand big capital investments. Therefore expenses for
realization of the given mode reliability increase are considerably lower than
charges on superfluous reserves of material, technical and working resources,
and the more so than expenses are caused by consequences from failures in
transportation process.
Use of the
offered approach to reservation allows to optimize reliability level of
transportation process in automobile transport. The solution of this problem is
based on minimization of the cumulative expenses received by summation of
charges on reserves material, technical and working resources, expenses on
functional reserves steering formation
and the expenses caused by consequences from failures in transportation process
(Fig.2).
Fig. 2 - The offered approach to optimization of reserves
Levels of
transportation process reliability shown on the pic.3.4 are charactarised by:
-
quantity criteria that is by
redundancy of obvious and latent reserves of material, technical and working
resources in main and auxiliary operations of technological process of
transportation.
-
quality sign that is by ability of
the transportation executor to form resource links and to switch reserve working
modes.
The size (
) which is optimum or critical point, showing economic
non-efficiency of further investment of facilities in the increase of
functional reserves of management, redundancy is marked on Fig. 2.