Karolina PROBIERZ[1]
Analiza zakłóceń w przepływach logistycznych w przedsiębiorstwie Branży MasZYN Górniczych
Streszczenie. W artykule zidentyfikowano i przeanalizowano zakłócenia, które występują w trakcie realizacji zadań transportowych i magazynowych. Wybrano zakłócenia występujące najcześciej w realizowanych procesach transportowych i magazynowych. W pracy przedstawiono także możliwe sposoby usprawnień występujących zakłóceń. Artykuł ma charakter praktyczny.
Słowa kluczowe: Przepływy logistyczne, analiza zakłóceń, procesy transportowo-magazynowe.
Analysis
of disturbances in logistic flows in MINING MACHINERY company
Summary. Disturbances that occur in the course of
transportation and storage tasks has been identified and analyzed. Disturbances
occurring the most frequently in the ongoing processes of transport and storage
have been selected. The article also shows possible ways of improvements of
occurring disturbances. The
article is of a practical nature.
Keywords: Logistics flows, analysis of
disturbances, transportation and warehousing processes.
1. INTRODUCTION
The internal warehouse transport
plays an important role in manufacturing companies (unit and small series
production) operating in the machine industry, as it is directly related to the
manufacturing logistics. This transport, in particular, involves movement of
products over small distances that are dependent on the spatial distribution of
the company as well as the so-called components of the infrastructure of the
production process and their locations. This transport includes movements both
within the area of warehouse facilities and between various facilities located
on the premises of the production plant.
The main elements of the transport
process in a warehouse facility and outside of the warehouse facilities that
support the production process include:
Fig. 1. Major components of the transport process
Rys. 1.
Główne składowe procesu transportowego
Source: Own study based on [5].
The concept of transport processes
(internal) is meant as a transportation process from one place of the company
to another (production site, warehouse) [4,7].
Internal transport is closely related to the flow
paths of raw materials, finished products within a specific organizational unit
[6].
The shaping and selection of the
transport solution constitutes the key element of the management-related
issues, since the internal transport process within a company is one of the
main processes of logistical activity [1, 2]. Internal transport system [ITS]
is thus a binder that keeps together all the logistical processes in the
warehouse facility. Should such a system lose efficiency, the warehouse can be
paralyzed (stock shortages, delays, congestions, etc.), which may lead to a
shutdown of the entire supply chain. Therefore this system must be properly
designed and then monitored and evaluated. To that end, it is necessary to
develop appropriate ITS assessment methods in the warehouse facilities that
support production processes.
The internal transport is one of the most important additional processes in all the companies (service, manufacturing and production as well) Internal transport in all of these companies is responsible for the implementation of information and material flow. The implementation of information and material flows may be hindered by an interruption. The analysis of the interruptions in the implementation of the flows within production plants is a complex process consisting of several stages. It includes, among others, the identification of [3]:
-
the
location where the interrupting factor appears (e.g. the production line, a
particular workstation, a supplier, the transport system),
-
the
elements which cause interruptions (e.g. an employee, transport equipment,
machinery),
-
the
sources of interruption (e.g. shortages in the personnel or equipment, a malfunction,
shortages of materials, missing information, new urgent orders, late receipt of
materials),
-
the
deviations as the results of the interruptions,
-
the
losses related to the occurrence of the deviation (e.g. the lengthening of the
production cycle, excessive stock amounts).
The interrupting factors also
include all the unexpected events that have a destructive influence on the
implementation of the flows and which cause the balance or the goal of the
production plant activity to change. In order to identify interruptions in the
flows, one can take advantage of daily flow examinations within the company
using sheets in which the employees make notes about the interruptions on the
daily basis or e.g. the fish-bone diagram. For the search of the root causes of
the identified interruptions, one can use the 5Why approach.
2.
IDENTIFICATION
OF INTERRUPTIONS IN THE SELECTED COMPANY – DESCRIPTION OF THE METHOD
As a result of ongoing research
based on observation, interviews and interruption sheets, information on the
interruptions in the internal transport and warehousing systems were obtained.
For this reason, field studies aimed at identification of the most significant
interruptions were conducted in the selected company. The study used
interruption measurement sheets. The deviations in material flows were
categorized on a 3-step scale:
-
group
1: occurs rarely (once every a few months),
-
group
2: occurs occasionally (at least once a month),
-
group
3: occurs frequently (at least once a week).
The study was conducted over the
period of 3 months. Every day the internal transport and warehousing employees
got interruption measurement sheets, in which they took notes on the
interruptions. At the end of the shift, a researcher collected the sheets.
The interruption measurement sheet
is shown in table 1.
Table 1 Interruption measurement sheet |
|||
|
Date: |
Equipment utilization level during
the shift |
||
|
Factors No. |
Name of a factor |
Was there an interruption? (if
yes, put X) |
Number of occurrences (put an X
whenever there was an interruption) |
|
1 |
|
|
|
|
2 |
|
|
|
|
3 |
|
|
|
|
4 |
|
|
|
|
5 |
|
|
|
|
N |
|
|
|
|
Source: Own
elaboration |
|||
Two types of interruption
measurement sheets were developed. The first sheet applied to the interruptions
that occur in the transport between the warehouse facilities and the production
/ assembly halls as well as between the production halls and the assembly
halls), while the other applied to the transport directly in the warehouse.
Throughout the period of the study, 420 measurement sheets were handed out for
warehouse transport equipment and 480 measurement sheets were handed out for
the equipment used in transport outside of the warehouse.
3.
IDENTIFICATION
OF INTERRUPTIONS IN THE SELECTED COMPANY
Based on the observation and
interviews, groups of interruption factors were identified. For warehouse
transport, such a group consists of 44 factors that may influence the transport
in the warehouse facilities.
For the system of transport between
the company facilities, 38 transport interruptions were identified.
As a result of the research, the key
bottlenecks (interruptions) were identified in the internal and warehouse
transport process. The major bottlenecks were selected on the basis of an
analysis of the interruption measurement sheets. The major interruptions were
the ones that are most frequently mentioned, that is to say the ones that were
categorized within group 3 (interruptions that occur at least once a week). The
major interruptions that occur in the internal transport within a warehouse
facility include the interruptions presented in Table 2.
Table 2 The major interruptions that occur
in the internal transport in a warehouse facility |
|
|
Interruption type |
Interruptions |
|
Human realted |
Late notification about the demand
for a load unit leading to material handling equipment being occupied and the
incapacity to perform the order on time. |
|
Organizational |
Lack of planning for supplier
arrivals. It is only agreed that deliveries are to be performed before 12
noon. |
|
The necessity to wait for an MHE
that performs transport to the production or assembly hall. |
|
|
No direct access to a single load
unit (moving or unpacking) |
|
|
Technical and technological |
Lack of regularity in the
warehousing tasks (leading to accumulation of orders) as a result of the lack
of regularity in the production, |
|
Production cycle variability that
causes the completed orders to not be received. |
|
|
The need to use a ladder to
retrieve small-sized load units. |
|
|
The necessity to manually enter
data into a computer system |
|
|
Source: own elaboration |
|
These interruptions belong to group
3, so they occur frequently – at least once a week.
Identical studies were conducted for
the internal transport outside of the warehouse facilities. The findings of the
studies are as follows. The most frequent interruptions (bottlenecks) are the
interruptions presented in Table 3.
Table 3 The
major interruptions that occur in the internal transport of the warehouse
facilities |
|
|
Interruption type |
Interruptions |
|
Organizational |
Excessive number of routes from
the initial part assembly hall to semi-finished product warehouse facility
for the purpose of transporting into the unit assembly hall. |
|
Waiting with the material for a
warehouse MHE. |
|
|
Technical and technological |
The production cycle variability |
|
Lack of regularity in the
warehousing tasks (leading to accumulation of orders) as a result of the lack
of regularity in the production |
|
|
The size of the load makes unloading
the material more difficult, which causes waiting for the material handling
equipment |
|
|
The weight or dimension that makes
it impossible to transport more than one load unit at a time |
|
|
Exhausted transport infrastructure |
|
|
Source: own elaboration |
|
As can be seen, a large number of
interruptions are the same for both warehousing and internal transport tasks.
The employees of the company pointed to the same factors. The study also
determined the average utilization level for the internal transport and warehousing equipment, which was 83% and 85% for
warehouse transport and internal transport, respectively.
4. SUMMARY
As part of the study based on the
interruption measurement sheets, the most frequent interruptions were
identified, which were then discussed among experts in order to attempt to
address the identified problems. The final rationalization and improvements
applied to these interruptions that can be considered controllable from the
point of view of internal and warehouse transport and do not entail production
changes.
Some of the identified interruptions
are closely related to the nature of the company, more specifically to the
characteristics of the production process that takes place in it. The timing
and parameters of the internal / warehouse transport process are results of the
type of production. Unit and small series production is characterized by a high
level of randomness, thus it is impossible to eliminate interruptions, such as:
-
lack
of regularity in the warehousing tasks as a result of the irregularity in the
production,
-
production
cycle variability that causes the completed orders to not be received,
-
late
notification about the demand for a load unit leading to material handling
equipment being occupied and the incapacity to perform the order on time.
Additionally, due to the character
of the devices produced in the studied company, it is similarly impossible to
eliminate the following interruption: weight or dimension that makes it
impossible to transport more than one load unit at a time.
The last of the most frequent
interruptions for which no improvements were attempted to be made is the
exhausted transport infrastructure. The current state of the transport
equipment, according to the maintenance department, does not constitute a major
issue that could cause the bottlenecks to appear in the process. Any
malfunction that takes place in the equipment is repaired very quickly.
Furthermore, the plant has some additional transport equipment, which can be
used to replace the existing equipment in the event of a major failure that
could render a quick repair impossible. In the current situation, the
investment in a new transport infrastructure is not supported by a business
necessity and the profitability of the investment. The company plans to replace
the transport infrastructure in the future, though, in line with the adopted
strategy and performance supervision plan for these devices. All the
interruptions that were not discussed are very poorly controllable from the
viewpoint of the internal and warehouse transport.
The following was proposed to help
resolve the existing interruptions:
-
elimination
of the manual data insertion into the IT system during the goods-in or
goods-out process in the warehouse facilities through application of bar codes,
-
elimination
of the manual labor during the warehousing tasks (a ladder in the closed
purchasing warehouse facility),
-
implementation
of the Kanban system for warehousing processes for the standard products of the
company (universal – without the implemented structural and technological
changes of the product),
-
introduction
of appointments for suppliers in order to eliminate the accumulation of the
warehousing tasks,
-
authorizations
for internal transport operators in the semi-products warehousing facility to
unload semi-products in the goods-in area,
-
installation
of a hoist in the production halls to enable unloading of heavy items without
waiting for overhead cranes.
Bibliography
1. Abt S. 2001. Logistyka w teorii i praktyce. [In Polish: Logistics in theory and practice]. Poznań: Wyd. AE.
2. Abt
S., H. Woźniak. 1993. Podstawy logistyki.
[In Polish: Fundamentals of logistics]. Gdańsk: Wyd.
Stella Maris
3. Kramarz
W. „Model sterowania przepływami materiałowymi w sieci produkcyjnej”. [In Polish: “Model control the
material flows in the production network”]. In ZN Politechniki Śląskiej, seria: Organizacja i Zarządzanie 60:
153-163.
4. Kozłowski
R. (red.). 2009. Podstawowe zagadnienia współczesnej logistyki. [In Polish: Basic issues of modern
logistics]. Polska, Kraków: Wolters Kluwer.
5. Lissowska
E. (red.). 1975. Technologia procesów
przewozowych w transporcie samochodowym. [In Polish: Technology of
transport processes in road transport]. Warszawa: WKŁ.
6. Ładoński W. 1994. Podstawy towaroznawstwa ogólnego. [In Polish: Fundamentals of general commodities]. Wrocław: Wydawnictwo Akademii Ekonomicznej.
7. Probierz
K., A. Sładkowski. 2014. „Use
of the internal transport systems in the process of warehousing”. In Современный город: проектирование, строительство и развитие. Материалы международной научно-практической конференции по строительству и архитектуре: 158-166. УрФУ. Екатеринбург. [Sovremennyjj gorod:
proektirovanie, stroitelstvo i razvitie. Materialy mezhdunarodnojj
nauchno-prakticheskojj konferencii po stroitelstvu i arkhitekture: 158-166.
UrFU. Ekaterinburg].