View
214
Download
0
Category
Preview:
Citation preview
Prof. Dr.-Ing. Bernd Noche
Fakultät für Ingenieurwissenschaften
Abteilung Maschinenbau
Institut für Produkt Engineering
Transportsysteme und -logistik
Keetmanstr. 3-9
47058 Duisburg
Telefon: 0203 379-2785
Telefax: 0203 379-3048
eMail: bernd.noche@uni-due.de
UNIVERSITÄT
D U I S B U R G E S S E N
Campus Duisburg
tul
ABC-/XYZ Analysis
Introduction
Quelle: Powerpoint-Folien: Uta Horstmann
M0000
2 ABC-Analysis
A short definition of ABC-Analysis
The ABC-Analysis represents a simple method
of material classification in respect of value and
quantity. (G. Wöhe)
Expressed in a more general way it is a process in order to identfy
important kinds of customers, suppliers or articles.
M0000
3 ABC-Analysis
The Pareto principle
The so called Pareto principle indicates that for many phenomenons the
following is valid:
80 % of effects are reached by 20 % of causes.
The principle traces back to Vilfredo Pareto (Italian economist) who, related to
Italy, had noticed that 80 % of property belonged to 20 % of the Italian
population.
Vilfredo Federico Damaso
Pareto
1848 - 1923
M0000
4 ABC-Analysis
However, the rule often is misunderstood:
It seems that 80 % + 20 % = 100 %.
But it can also be valid that:
80 % of effects are traced back to 10 % of causes.
The principle can also be applied recursively, and not only used for 20% of the
reasons :
e.g. 64-4 Rule: e. g. (80 – 16) % (20 – 16)%
96-36 Rule: e. g. (80 + 16) % (20 + 16)%
64-4 Rule: e. g. from (80•80/100)% - (20•20/100)%
51,2-0,8 Rule: e. g. from (80•80•80/10000)% - (20•20•20/10000)%
Source: Wikipedia
M0000
5 ABC-Analysis
ABC classification
Cumulated proportion
(percentage)
Cumulated
Value percentage
or
Percentage share
of sales
10 20 30 40 50 60 70 80 90 100
100
90
80
70
60
50
40
30
20
10
A
B
C
M0000
6 ABC-Analysis
ABC classification
B Goods Intermediate materials
C Goods Low value or share of sales percentage,
high proportion
A Goods High value or share of sales percentage,
low proportion
Value Proportion
ca. 80%
(70-80%)
ca. 10%
(gering)
ca. 15%
(15-20%)
ca. 20%
(10-40%)
ca. 5%
(5-10%)
ca. 70%
(> 40%)
Example of values:
M0000
7 ABC-Analysis
Goals of the ABC Analysis
Separation between
essential and non-essential
Avoidance of uneconomical efforts
Identification of starting
points for improvement
M0000
8 ABC-Analysis
Measures for A goods
Disposal Stock avoiding inventory management
Exact determination of (low) safety stock Order based
instead of consumption based management by value
percentages.
Consumption based management by high sales
percentages.
Order processing
Intensive price negotiations
Qualification of alternative suppliers
Fast invoice cycle in order to secure cash discount
periods.
Inventory Permanent inventory
M0000
9 ABC-Analysis
Different kinds of handling of M types regarding
• Purchase market research Global Sourcing e-procurement
• Value analysis necessarily not necessary
• Assessment of demand deterministic stochastic
• Stock-taking permanent Once a year
• Safety stock small big
• Order cycle high -JIT greater cycles
A part C part
M0000
10 ABC-Analysis
Analysis example:
Material
Yearly
demand
(in piece)
Costs
(per piece
in Euro)
Contribu-
tion to total
costs (in
thousand
Euro)
Relative
contribu-
tion to
total costs
Cumulated
contribution
to total
costs
Classifica-
tion
Relative
contribu-
tion to
quantity
percen-
tage
1 300.000 10,00 3.000 3% 30%
2 10.000 3.000,00 30.000 30% 1%
3 90.000 500,00 45.000 45% 9%
4 200.000 100,00 20.000 20% 20%
5 400.000 5,00 2.000 2% 40%
Sum 1.000.000 100.000 100% 100%
1 2 5 6 4
M0000
11 ABC-Analysis
ABC Analysis procedure
1. Determination of absolute total costs
Absolute total costs = yearly demand * piece price
2. Determination of relative proportions of the total costs Relative proportion of total costs = absolute total costs / total costs
3. Sorting according to relative contribution to total costs
(in descending order)
4. Accumulation of relative contributions to total costs
5. Classification of materials into three categories Accumulation of individual relative total costs
6. Determination of relative quantity proportions Relative quantity proportion = yearly demand/ total demand
7. Summation of relative quantity proportions per material class
M0000
12 ABC-Analysis
Analysis example – based on value
Material Yearly
demand
(in piece)
Costs
(per piece
in Euro)
Contribution
to total costs
(in thousand
Euro)
Relative
contribu-
tion to
total costs
Relative
contribu-
tion to
quantity
percen-
tage
Cumulative
contribution
to total
costs
Classifi-
cation
1 300.000 10,00 3.000 3% 30% 98% C
2 10.000 3.000,00 30.000 30% 1% 75%
A
3 90.000 500,00 45.000 45% 9% 45% A
4 200.000 100,00 20.000 20% 20% 95% B
5 400.000 5,00 2.000 2% 40% 100% C
Sum 1.000.000 100.000 100% 100% 100%
M0000
13 ABC-Analysis
Analysis example – based on quantity
Material Yearly
demand
(in piece)
Costs
(per piece
in Euro)
Contribution
to total costs
(in thousand
Euro)
Relative
contribu-
tion to
total costs
Relative
contribu-
tion to
quantity
percentage
Cumulative
value to
total sales
Classifi-
cation
1 300.000 10,00 3.000 3% 30% 70% A
2 10.000 3.000,00 30.000 30% 1% 100%
C
3 90.000 500,00 45.000 45% 9% 99% C
4 200.000 100,00 20.000 20% 20% 90% B
5 400.000 5,00 2.000 2% 40% 40% A
Sum 1.000.000 100.000 100% 100% 100%
M0000
14 ABC-Analysis
Different ABC analyses
Criterion Reasons
Stock value Amount of capital lockup;
Stock reduction potential
Quantity of consumption Order picking; Warehouse organisation;
storage strategies
Turnover ratio Sales volume ; Assignment in
warehouse
Volume of sales Amounts of coverage; Selection of
scheduling methods
Service level Safety stock; customer satisfaction
Reference volume of suppliers Supplier selection
Amount of demand Material requirements planning; Sales
volume
M0000
15 ABC-Analysis
Fields of application
Range Character Key figure
Purchasing
Material / Material
groups Purchasing volume
Supplier Invoice amount
Sales Product Sales
Sales organization Incoming orders
Marketing Clients / Client groups Sales
Sales area Sales
Quality management Supplier Defective products
Inventory management Material Access frequency
M0000
16 ABC-Analysis
Criticism on the methodology of ABC Analysis
The classification into only three categories us very rough.
The determination of limiting values is based on empirical
values and is thus random.
The ABC Analysis offers only a figure of the current
actual situation.
M0000
17 ABC-Analysis
Summary
Characteristics of the ABC Analysis
• General classification of characteristic values in respect of the importance with certain operating figures.
• Concentration by the following trisection:
Advantages of the ABC Analysis
• Analysis of complex problems with justifiable effort (by focussing on the essential factors)
• Simple application (in many fields)
• Very clear and graphical presentation of the results
A important premium top-selling
B less important median average levels of
turnover
C Relatively
unimportant
low-value narrow market
M0000
18 ABC-Analysis
XYZ Analysis
Category Consumption Ability to
schedule
X constant, fluctuations rarely High
Y Wilder fluctuations, often for reasons
of trend or seasonal reasons Middle
Z Completely unsteady Low
The ABC Analysis is often combined with a XYZ Analysis.
M0000
19 ABC-Analysis
Disposal process with a combination of ABC and XYZ
Analysis
(Source: Österreichisches Schulportal des Bildungsministeriums)
227 135 50 42 ∑
111 101 10 0 Z
42 32 8 2 Y
74 2 32 40 X
∑ C B A
Classification of conductor plates according to ABC/XYZ Analysis
Recommended Disposal processes
M0000
20 ABC-Analysis
Determination of scheduling guide lines
Quelle: RWTH Aachen
Delivery of components
from the inventoy buffer
of the supplier
synchronous to
production
Implementation of a supplier
kanban by using a logistics
service provider
Inventory buffer at the
production site
M0000
21 ABC-Analysis
Classification of parts for die program and stock production
Type
A-Parts
Production
release Charakterization
deterministic • Date and lotsize are fixed
• low fluctuations in demand
B-Parts order operated • Date and lotsize depend on current,
deterministically identified demand
C-Parts consumption-driven • Lotsize is fixed
• Dates according to consumption of
parts
M0000
22 ABC-Analysis
…AX good can be planned in more detail than CZ goods…
high value percentage
continuous demand
high predictive value
average value percentage
continuous demand
high predictive value
low value percentage
continuous demand
high predictive value
low value percentage
irregular demand
low predictive value
average value percentage
irregular demand
low predictive value
average value percentage
fluctuating demand
average predictive value
low value percentage
fluctuating demand
average predictive value
high value percentage
fluctuating demand
average predictive value
high value percentage
irregular demand
low predictive value
X
Y
Z
A B C R R
R
{Potential for Rationalization Control complexity }
C C
C
M0000
23 ABC-Analysis
The material portfolio
Provision principles
• Strategical material
• Bottleneck material
• Handle material
• Noncritical material
„Relevance for the result“
vs.
„Exercise risk“
Quelle: „Grundzüge der Beschaffung, Produktion und Logistik“, Pearson Studium
Handle material Strategical
material
Noncritical Bottleneck
material
Relevance
for
the result
Exercise risk
high
high low
M0000
24 ABC-Analysis
The material portfolio
• Strategical material:
close oberservation and exact forecasts, long-term supplier
relations, joint projects
• Bottleneck material:
additionally more suppliers or other material
• Handle material:
intensive discussions about price, order size optimization
• Noncritical material:
rough planning, stockpiling, standardization,
reduction of suppliers
M0000
25 ABC-Analysis
Program-oriented determination of demand
Parts lists:
Parts lists according to
amount
Parts lists according to
structure
Modular parts lists
Quelle: „Grundzüge der Beschaffung, Produktion und Logistik“, Pearson Studium
Upper part complete
Article code Description
Article code 10 Description: gear box
Drag
Axle drive shaft complete
Back gear complete
Screw
Axle drive shaft complete
Axle
Center box
bearing
bearing
Splined key
Axle complete
Screw
Axle
Cope
Gear wheel
Gear wheel
Gear wheel
Gear wheel
Piece
M0000
26 ABC-Analysis
Gozintograph
Quelle: „Grundzüge der Beschaffung, Produktion und Logistik“, Pearson Studium
The Gozintograph is a directed graph which
describes what parts make up one or more
products. Thereby, the production process can
be multi-level, whereas the input consists of raw
materials, semi-finished and finished parts. In
the Gozintograph is listed how these parts are
quantitatively linked. Thereby, the knots describe
the parts and the directed edges specify how
many units of a part incorporate into a unit of a
downstream part. (Wikipedia)
M0000
27 ABC-Analysis
JIT as a total concept
Objective: „Elimination of the enduring waste and delay
at each step from the raw material to the end customer …“
i.e. not only a production synchronous procurement, but also:
Minimization of waiting time (Zero Lead Times)
Minimization of workin time requirement (Zero Handling)
Minimization of set-up times (Zero Set-Up)
Minimal lot sizes (Zero Lot Size)
Minimization of Quality defects (Zero Defects)
Minimization of fluctuations in production (Zero Surging)
Quickest troubleshooting and preventive maintenance (Zero Breakdown)
Quelle: Prof. Dr.-Ing. W. Ullmann
M0000
28 ABC-Analysis
Objective of the JIT logistics is to guarantee a maximum added value in
manufacturing processes:
Minimal material coverages at the place of consumption (max. 120 min)
Frequent delivery (picking at a high variety)
Removal-compatible provision, Tendency to special carriers,
Avoidance of packing material
Minimal number of handling steps, ideally „ship-to-line“ without receiving storage
location; placed on the line directly from the supplier
Route controlled delivery according to schedule, use of logistics hauls instead of
forklifts (bus instead of taxi principle)
Use of Material providers for the constand distribution, maybe separation of
material
Self-controlled Kanban control loops for continuous consumptions
JIT logistics
M0000
29 ABC-Analysis
JIT logistics (cont.)
Trustful partnersip between supplier and consumer because of the
increased uncertainty of the supply due to inventory reduction,
Common continuous improvements in the collaboration between
partners,
Reduction of the number of suppliers („single sourcing“) due to high
handling costs,
The short-term nature of delivery schedules requires a high flexibility of the supplier,
Production without inventory is only possible when the configuraton of the single
delivery schedules occurs with the highest degree of accuracy,
Zero defects quality („100% good parts“),
Integration of efficient logistics service providers,
Integrative, economic levels spanning information supply.
M0000
30 ABC-Analysis
Synchronous processes in single piece flow reduce inventories!
Highly frequent materials handling
in small quantities :
Small load carrier replace bulk containers
Logistics hauls replace forklifts
(Bus instead of taxi-principle)
JIT logistics
M0000
31 ABC-Analysis
The origin of the KANBAN system
The beginnings of the KANBAN system go back to the fifties of this century.
Reasons (Raumknappheit, Kapitalmangel) forced the enterprisers (espcially
in Japan) to particular strains to reduce their inventories and den to rationalize
the material flow withing the production area and also between the plants.
From this rethinking the Just-in-time principle (JIT) was developed and the
KANBAN system as a particular form of realization.
This system can not only be transferred to the area of purchase and
stockkeeping, but it can also be used as a simple self-regulating
manufacturing control.
M0000
32 ABC-Analysis
Objectives of the KANBAN system
Reduction of material stocks
Reduction of lead times
Increase of transparency of the operational process
Increase of working productivity
Increase of flexibility regarding the short-term willingness to
supply
Increase of quality control
A KANBAN system is essentially characterized by a low
amount of control installation and beyond that it pursues the following logistics
objectives :
M0000
33 ABC-Analysis
Functionality of the KANBAN system
Division of production in a system of meshed, self-regulated control circuits,
consisting of each with a parts concsuming area (sink) and the belonging
upstream parts producing area (source).
Setup of an intermediate bearing (buffer) between parts consuming and parts
producing area in order to compensate irregularities or interruptions in the
production process.
Introduction of the pull principle for the each with successive consuming area.
Use of special information carriers that serve as KANBAN route cards for the
actual manufacturing control.
Assignment of the short-termin control responsibility to the executing
employee so that a central manufacturing control is no longer necessary.
The most important elements of the KANBAN system are:
M0000
34 ABC-Analysis
Material and information flow in production
organized as a KANBAN system
Pro
cu
rem
ent
Cut
Mechanical
production
KANBAN control
Welding
shop
Asse
mb
ly o
f p
rod
uct
Cu
sto
mer KANBAN control
External supplier
KANBAN control
Sub-a
sse
mbly
KANBAN control
KANBAN control KANBAN control
Intermediate storage Production area Material flow Control
M0000
35 ABC-Analysis
Kinds of KANBAN control
Transport Kanban
The transport kanbans control the
material flow between the warehouse
and the successive production area.
For this tasks the transport kanbans
are provided with the following
information to each part:
• Article code
• Name
• consuming area
• producing area
• storage location
• kind of box
• box capacity
Production Kanban
Production kanbans control the
information and material flow
between the producing area and the
warehouse and typify the production
orders for the single parts.
Beside all data of the transport
kanban a production kanban
additionally contains information
about kind and quantity of the
dependent requirements for the
production of the semifinished
product respectively the product.
M0000
36 ABC-Analysis
Control questions to the ABC-/XYZ analysis
1. What is your understanding of ABC- und XYZ analysis?
2. What does the principle of Pareto mean?
3. What does the Lorenz curve express?
4. What is the procedure for both methods?
5. What has to be considered with A-articles?
6. Why do you have to perform a combined ABC-/XYZ analysis?
7. What is meant by the material-portfolio?
8. What do you understand by Kanban?
9. Which two types of kanban control do you know?
10. What has to be considered with the JIT concept?
11. What is a parts list?
12. What kind of parts lists do you know?
13. What is a Gozintograph?
M0000
37 ABC-Analysis
Literature
1. T. Gudehus, „Logistik – Grundlagen, Strategien, Anwendungen“, 3.Aufl.,
Berlin: Springer-Verlag, 2005
2. M. Lensing, „Materialwirtschaft und Einkauf“, Gabler Verlag, 2009
3. H. Wannenwetsch, „Integrierte Materialwirtschaft und Logistik: Beschaffung, Logistik,
Materialwirtschaft und Produktion“, 4. Aufl., Springer Verlag, 2010
4. R. Vahrenkamp, „Logistik. Management und Strategien“, 6. Aufl., Oldenbourg Verlag, 2007
5. Kee-hung Lai, T.C.E. Cheng, „Just-in-Time Logistics“, Gower Publishing, Ltd., 2009
6. H. Takeda, „Das synchrone Produktionssystem: Just-in-time für das ganze
Unternehmen“, 7. Auflage, Vahlen Verlag, 2012
7. H. Werner, „Supply Chain Management: Grundlagen, Strategien, Instrumente und
Controlling“, 4. Aufl., Gabler Verlag, 2010
8. R. G. Poluga, „Quistissenz des Supply Chain Managements: Was sie wirklich über Ihre
Prozesse in Beschaffung, Fertigung, Lagerung und Logistik wissen müssen“, Springer
Verlag, 2010
9. R. Koether, „Taschenbuch der Logistik“, 4. Aufl., Hanser Verlag, 2011
Recommended