Forecasting model of manufacturing time at the early design stage of product and process/gaminio ir proceso gamybos laiko prognozavimo ankstyvoje ju kurimo stadijoje modelis.
Bargelis, A. ; Baltrusaitis, A. ; Dubinskas, E. 等
1. Introduction
The survival of manufacturing companies in new modern manufacturing
environment with competition, productivity, globalization and people
cleverness is related. The majority of manufacturers in East Europe are
going to produce the separate parts or small batches orders proposing
similar manufacturing cost, quality and delivery time. These factors
become the main criteria of customers choosing the manufacturer [1]. The
quotation of a new manufacturing order is very responsible work because
it has a short time and must be more as possible precise. Moreover,
customers are very hurry getting proposals for orders cost and delivery
time; therefore, the definition of new orders time and cost requires
advanced statistically based methods for evaluation and definition the
work time and cost at the early every order negotiation stage. The
forecasting model is more suitable for such objective, only one problem
exists--how much it could be reliable and how quickly it could be
developed. The benefit of a suitable forecasting model is as follows: it
helps to make a proper planning of company resources, to keep the good
partnership with customers and partners, to seek a better
competitiveness in markets. On the other hand customers can quickly
estimate the manufacturers' possibilities and attractiveness for
one or another production order and proposal.
The manufacturing engineering is a creative, imperative process and
needs of much specific knowledge, facts and experience, new
technological ideas and collaborative work with products'
designers, marketing managers and producers. Product and process
development must be integrated and overlapped with various job steps
applying concurrent engineering approach. These activities aiming to
increase a new product performance and to upgrade the process decreasing
manufacturing cost. The developers search various solutions of products
and processes design using different design features (DF), quality,
quantitative and functional parameters, materials, surface roughness and
mutating product's work conditions. The classification of products,
their parts and DF has the objective to facilitate and to accelerate
product's process development at the early design stage where is
necessary to create and evaluate some processes' alternatives [2].
The main objective of this research is to create and investigate
the new methodology of manufacturing time forecasting model at the
product and process early development stage. This new methodology on
group technology [3] is based, when DF into separate classes level have
been classified according to their design and manufacturing properties.
The statistical data and equation of distribution separate DF classes in
the mechanical parts have been acquired and created. The product and its
parts development of 3D CAD model in virtual environment (VE) have been
created. It shows how correctly is possible to develop the product
virtual prototype from different and various DF seeking better
manufacturability and least manufacturing cost. Created methodology
considers the contradictions of a product design procedure and created
properties and value and also among the principles of manufacturing
engineering seeking best alternative with minimal cost. The paper
considers described problems in manufacturing of large number product
types and low production volumes in order handled manufacturing systems
(OHMS). The findings and developments slightly can be used in mass
production systems also. The mathematical formalization of a developed
methodology is provided and appropriate techniques are created.
2. The consideration of removed material volume influence to the
part machining time
First variant of such methodology [4] has been created seeking the
definition of machining time at the early process design stage and
applying computer-aided process planning (CAPP) systems. This
methodology on the DF systematization, distribution in parts and
products, and classification is grounded. It was successfully applied
for some CAPP software developments using DF individually and
developments have been implemented in various manufacturing companies.
This methodology, however, has some disadvantages: complicated
extraction of DF from parts and products, and definition of distribution
allowances in various operations, impossible forecasting of
manufacturing resources at the early stage of a new product and process
design.
The second upgraded variant of a mentioned methodology in this
paper is discussed. The consideration of new approach consists of four
stages as follows: 1) part 3D CAD model creation in virtual environment
(VE); 2) DF classes and subclasses attribution to parts and products; 3)
definition of a removed material volume using created part 3D CAD model;
4) development of mathematical formalization for part's machining
time definition.
2.1. Part design in virtual environment
During engineering design the main problem is finding the
innovative ideas and how to keep creativity in designing procedure? The
customers' and clients' requirements and consideration of
markets often are general issue to product type acquisition and best
process choosing. During the past decade the nature protection and
ecological sustainability requirements in manufacturing industry
increase the reliability of engineers' decisions. Mechanical
engineers together with wide range of other people involved in
manufacturing business also with customers and sellers must collaborate
seeking all the best in a new product and process development. It
includes the new ideas and technical solutions generation and
implementation also strategy creation. They develop products and
processes in VE, applying computerized systems and other infrastructure
means and techniques. New ideas can seldom appear suddenly, using
inventions or seeing them in fairs or in competitor's sites. Ideas
can be usually stimulated by customers requirements upgrading already
developed either outdated products and processes or discussing various
possibilities and exchanging by sketches, photographs, virtual and
physical prototypes and deep collaboration in experience and development
[5]. Ideas generated by mechanical engineers often are the result of
thorough and long job in the particular, separated field of development
products and technologies satisfying the customers 'requirements or
solving problems related with products 'performance, properties and
characteristics. The time for this always is short and creativity of
people involved for these tasks are uncompleted.
In modern manufacturing environment dominates minimal production
cost, products' performance and quality. This depends on number of
quality errors and equal consumption of manufacturing resources. The
prevention of product and process development errors and defects at the
early design stage becomes very important. The virtual reality (VR)
technologies and means as design, modeling and simulation systems in VE
are more and more prevalent and useful [6]. The shareholders of
manufacturing companies and organizations make significant investments
for above mentioned techniques and bigger part of engineers from
manufacturing divisions are displaced to work in development of
mentioned means. The traditional and nontraditional ways for this aim is
used. Traditional way with development of new modern machinery and
tooling, materials and manufacturing methods in many cases are related
while non-traditional way is divided for development of infrastructure
systems and techniques that are capable to decrease a manual work level
in shop floor and routine work of engineers in research and development
(R&D) departments. VR technologies award new and innovative
capabilities for humans applying advanced new and innovative products
and processes development systems based on artificial intelligence (AI).
If two - three decades earlier in R&D departments of companies and
organizations dominated human-machine systems as computer-aided design
(CAD), computer-aided process planning (CAPP) and enterprise resources
planning (ERP), so now tendency slightly is going to use the AI based
systems [4] in products and processes development procedures. The
knowledge-based (KB) and expert systems (ES), also VR technologies are
divided for product and process conception and pilot project development
and visualization in virtual environment [7, 8]. Fig. 1 presents the
main functions of part development in VE: 3D dimensions' data
acquisition and sharing among users in computerized development
environment, work piece design, basic surfaces accuracy and roughness,
available customers and partners involvement in process development
aiming high quality and minimal manufacturing cost [9-12].
Engineers' work in VE helps to precisely perceive how it looks in
reality and to estimate the engineering value and incurred cost. This
gives good possibility for optimization of product and process
performance and properties at the early design stage solving tradeoffs
among developers, customers and manufacturers.
[FIGURE 1 OMITTED]
2.2. Parts' design features classification and definition
applying group technology in manufacturing
The engineering value of every part by applied DF type, size and
their quantitative-qualitative parameters and dimensions are defined.
Designer has to understand that each additional DF in product or part
will increase the manufacturing time and cost. This must be strongly
related with checking of value engineering and efforts for minimization
of materials consumptions and manufacturing time. On the other hand, the
increase of product performance and functionality also is contemporized
with DF quantity and concentration in whole part and product.
Every product has many characteristics distinguishing it's
from other products. Such characteristics and properties are result of
including the different DF and requirements of quality and quantity as
well as material, surface roughness, manufacturing conditions, and so
on. Classification of products or their DF is aimed to facilitating and
accelerating the process of developing manufacturing technology. For
easier and more convenient work, all the typical DF is classified into
two classes' level: cylindrical (1.1-1.5) Table 1 and
non-cylindrical (2.1-2.8) Table 2.
[TABLE 1 OMITTED]
[TABLE 2 OMITTED]
There are several areas in which this classification can assist to
engineers at the early design stage of products and processes. In
particular, it helps as integrated valuable tool for creation the
forecasting model of manufacturing time. It allows engineers to use
these unified DF classes without having to use huge data bases and
traditional calculations with many restrictions. This results in the
elimination of the time spent by designers during early phase of the
cost calculation and forecasting the manufacturing time. These data in
nowadays are decisive wining orders and searching cheapest alternatives
of a new product alternative.
2.3. The definition of a part machining time applying removed
material volume in 3D CAD model
The definition of removed material volume applying the part 3D CAD
model in virtual environment for forecasting the machining time at the
early its design stage, or new order engineering stage is used. Together
with this the definition of removed metal volume from all DF that are in
part is carried out. The mentioned procedure is presented in Fig. 2. It
shows a sequence of volume definition of whole part 3D CAD model and
it's every DF applying standard design software Solid Works. An
extraction of the part's DF and data input is performed at the
interactive regime.
[FIGURE 2 OMITTED]
The removed material volume V from part work piece during machining
operation as a main criterion of machining time [T.sub.m] has been used
[4]. The appropriate dependences lg [T.sub.m] and lg V have been created
for every DF. It is said that other factors influencing to the value of
machining time Tm as material ([t.sub.1]), accuracy and surface
roughness ([t.sub.2]), tool material ([t.sub.3]), production volume
([t.sub.4]) and specific peculiarities of a part ([t.sub.5]) are
conditionally constant and are expressed in Eq. (1). The influence of
latter variables to the value of manufacturing time [T.sub.m] is defined
by appropriate correction coefficients.
[T.sub.m] = [f.sub.1]([t.sub.1], [t.sub.2], [t.sub.3], [t.sub.4],
[t.sub.5]). (1)
The typical dependences of lg [T.sub.m] and lg V or nomograms are
presented in Figs. 4 and 5. The data of [T.sub.m] applying theoretical
calculations with optimal cutting speed and various materials, cutting
tools, different qualitative and quantitative parameters and experiments
forming all considered DF have been used. As a result of these
procedures the following equation for definition a theoretical machining
time [T.sup.T.sub.m] estimating the influence of DF complexity and
quantity has been created:
[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (2)
where m is slope of a regression trend line and C is intercept of a
regression trend line. Removed material volume is calculated as follows:
v = [V.sub.WP] - [V.sub.P], (3)
where [V.sub.WP] is part's work piece volume, [mm.sup.3], VP
is a part's volume, [mm.sup.3].
[FIGURE 3 OMITTED]
[FIGURE 4 OMITTED]
[FIGURE 5 OMITTED]
Values of m and C are calculated using appropriate nomograms (Figs.
4 and 5) [13]. The floor-to-floor time [T.sub.vnt.k] of a part
production at the early design or order engineering stage is calculated
as follows:
[T.sub.vnt.k] = ([T.sub.pp]/r) + [T.sub.past] + [T.sub.m], (4)
where [T.sub.pp] is a set up time, h; [T.sub.past] is a part's
gripping time in machine tool, h; [T.sup.c.sub.m] is a machining time
after correction, h; r is a manufacturing batch.
Table 3 presents the value of slope m and intercepts C of all DF
placed in Tables 1 and 2. Employing these data the part's
floor-to-floor or manufacturing time [T.sub.vnt.k] is defined at the
early product and part design stage.
[T.sup.c.sub.m] = [T.sub.m] [k.sub.l] [k.sub.2] [k.sub.3] [k.sub.4]
[k.sub.5], (5)
where [k.sub.1] is a correction coefficient of machining material;
[k.sub.2] is a correction coefficient of cutting tool material;
[k.sub.3] is a correction coefficient of machining accuracy; [k.sub.4]
is a correction coefficient of surface roughness; [k.sub.5] is a
correction coefficient of batch size. These coefficients are defined in
previous our job [4].
2.4. Part's DF statistical repartition and regularity creation
for forecasting of a machining time
The twenty six parts of prismatic class applying their 3D CAD
models have been considered. Table 4 shows parts, work pieces and DF
volumes and their repartition in percents while Table 5 presents
parts' and their DF theoretical and statistical machining times
(whole part theoretical [T.sup.T.sub.m] and statistical
[T.sup.s.sub.m]). [T.sup.s.sub.m] machining time and every DF
statistical repartition P in a part are defined as follows:
[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (6)
where [V.sub.DF] is removed material volume of DF [mm.sup.3];
[V.sub.R] is a removed total material from part work piece, [mm.sup.3];
n is the number of considered parts, i is considered part and j is the
considered DF.
The statistical average pi of removed material for every considered
part and every DF is defined (Table 6). Then knowing [p.sub.i] values
and total removed material volume from work piece [V.sub.R], the
statistical machining time [T.sup.s.sub.m] of the DF is calculated:
[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (7)
The bias P between part's theoretical machining time
[T.sup.T.sub.m] and statistical machining time [T.sup.s.sub.m]), is
computed as follows:
[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (8)
The Fig. 6 presents the bias of theoretical machining time m and
statistical machining time [T.sup.S.sub.m]. The bias fluctuated in
limits of 5 - 22% and for biggest number of considered parts goes to be
equal 18%.
[FIGURE 6 OMITTED]
3. Further research
The developed model partially is implemented in industry of
Lithuania. The implementation results in some companies have shown that
the model is able to forecast manufacturing time at the early stage of
new order engineering. It is planned to investigate and to upgrade of
developed model seeking better accuracy and application for bigger
variety of works and operations. Further research is devoted to the new
products as moulds and dies manufacturing time forecasting at the early
design stage. It could help to the better collaboration among customers,
suppliers, developers and manufacturers aiming lower cost and higher
performance.
4. Conclusions
The research in this paper presents an intelligent forecasting
model of manufacturing time at the early design stage of product and
process. The new product and process design is the essential task of the
manufacturing enterprise, in particular, for order handled manufacturing
system (OHMS). The forecasting model works in virtual environment (VE)
and is created considering products design features. The model is based
on dependence of removed material volume and machining time considering
parts material, accuracy, surfaces roughness and various machines and
tooling. It has been stated that machining time depends on the removed
material volume and type of a part design feature. The achieved
theoretical and statistical research results in close cooperation with
industrial companies have been gotten. Briefly it is concluded as
follows:
1. The basic dependence and regularity among removed material
volume, type of design feature and machining time has been found.
2. The mathematical formulation has been created that is able to
forecast the manufacturing time of a part at the early design or
manufacturing order engineering stage with sufficient accuracy
3. The bias between theoretical machining time
[T.sup.T.sub.m] and statistical machining time [T.sup.S.sub.m]
fluctuated in limits of 5-22% and for biggest number of considered parts
goes to be equal 18%.
Received December 19, 2011
Accepted January 16, 2013
References
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March.
[6.] Gong, Y.D.; Cheng, J.; Jiao, Z.J.; Yang, Y.X. 2009. Research
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5385136&tag=1.
[7.] Gao, Q.; Sun, H.; Lin, S. 2010. The application and
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[8.] Vern, K.; Gunal, A. 1998. The use of simulation for
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[9.] Saunders, M.N.; Seepersad, C.C. 2009. The characteristics of
innovative, mechanical products, Proceedings of the ASME 2009
International Design Engineering Technical Conferences & Computers
and Information in Engineering Conference IDETC/CIE August 30-September
2, San Diego, California, USA, p.1-10.
[10.] Jayaram, S.; Angster, S. 1996. VEDAM-virtual environments for
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A. Bargelis *, A. Baltrusaitis **, E. Dubinskas ***
* Kaunas University of Technology, K?stu?io str. 27, Kaunas,
Lithuania, E-mail: Algirdas.bargelis@ktu.lt
** Kaunas University of Technology, K?stu?io str. 27, Kaunas,
Lithuania, E-mail: alfredas.baltrusaitis@stud.ktu.lt
*** Kaunas Baltec CNC Technologies, Raudondvariopl. 148, Kaunas,
Lithuania, E-mail: edvinas@sebra.lt
http://dx.doi.org/10.5755/j01.mech.19.1.3620
Table 3
The coefficients' values of DF
classifier for prismatic parts
F m lgC
2.1 0.4471 -3.0894
2.2 0.9378 -3.7096
2.3 0.3665 2.3847
2.4 0.5441 -2.7871
2.5 0.8196 -3.9522
2.6 -0.0203 -0,3872
2.7 0.6269 -3.0455
2.8 0.4745 -2.175
Table 4
The considered parts, work pieces and DF volumes and their
repartition
Part [V.sub.WP], [V.sub.P] [V.sub.R]
No. [mm.sup.3] [mm.sup.3] [mm.sup.3]
1 1.1x[10.sup.6] 8.4x[10.sup.5] 2.4x[10.sup.5]
2 4.9x[10.sup.5] 3.4x[10.sup.5] 1.8x[10.sup.5]
3 8.9x[10.sup.5] 5.9x[10.sup.5] 2.9x[10.sup.5]
4 3.2x[10.sup.5] 2.4x[10.sup.5] 1.3x[10.sup.5]
5 2.6x[10.sup.5] 2x[10.sup.5] 5.6x[10.sup.4]
6 1.2x[10.sup.6] 1x[10.sup.6] 2.2x[10.sup.5]
7 5x[10.sup.4] 3.1x[10.sup.4] 3x[10.sup.4]
8 9.8x[10.sup.4] 5.3x[10.sup.4] 1.7x[10.sup.4]
9 2.4x[10.sup.5] 1.7x[10.sup.5] 7.5x[10.sup.4]
10 5x[10.sup.6] 4.7x[10.sup.6] 2.9x[10.sup.5]
11 2.6x[10.sup.6] 2.1x[10.sup.6] 4.6x[10.sup.5]
12 4.4x[10.sup.5] 3x[10.sup.5] 1.3x[10.sup.5]
13 1.1x[10.sup.5] 7.2x[10.sup.4] 3.8x[10.sup.4]
14 1.4x[10.sup.6] 1.3x[10.sup.6] 1.5x[10.sup.5]
15 1.6x[10.sup.6] 1.4x[10.sup.6] 1.2x[10.sup.5]
16 1.7x[10.sup.6] 1.3x[10.sup.6] 4.2x[10.sup.5]
17 6.1x[10.sup.5] 5.4x[10.sup.5] 7.3x[10.sup.4]
18 1.1x[10.sup.6] 9.6x[10.sup.5] 1x[10.sup.5]
19 1x[10.sup.6] 8.4x[10.sup.5] 1.8x[10.sup.5]
20 9.1x[10.sup.6] 7.5x[10.sup.5] 1.6x[10.sup.5]
21 1.4x[10.sup.6] 1.2x[10.sup.6] 2.6x[10.sup.5]
22 1.7x[10.sup.6] 1.4x[10.sup.6] 3.1x[10.sup.5]
23 1x[10.sup.6] 8.1x[10.sup.5] 2.2x[10.sup.5]
24 9.1x[10.sup.6] 7.3x[10.sup.5] 1.8x[10.sup.5]
25 1.4x[10.sup.6] 1.1x[10.sup.6] 2.9x[10.sup.5]
26 1.7x[10.sup.6] 1.6x[10.sup.6] 3.8x[10.sup.5]
27 6x[10.sup.5] 2.5x[10.sup.5] 3.7x[10.sup.5]
28 9.7x[10.sup.5] 4.9x[10.sup.5] 5.3x[10.sup.5]
[p.sub.i]
Part [MATHEMATICAL [MATHEMATICAL
EXPRESSION NOT EXPRESSION NOT
REPRODUCIBLE IN REPRODUCIBLE IN
ASCII] ASCII]
No. [mm.sup.3]/% [mm.sup.3]/%
1 2.2x[10.sup.5]/91.7 1.6x[10.sup.4]/6.7
2 4.3x[10.sup.4]/23.9 2.7x[10.sup.4]/15.1
3 2.7x[10.sup.5]/93.1 2.1x[10.sup.4]/7.2
4 1.2x[10.sup.5]/93.3 2.2x[10.sup.4]/16.9
5 4.6x[10.sup.4]/82.1 5.7x[10.sup.3]/10.2
6 - -
7 2.3x[10.sup.4]/76.7 4.3x[10.sup.3]/14.3
8 1.3x[10.sup.4]/76.5 2.1x[10.sup.3]/12.4
9 3.4x[10.sup.4]/45.3 2.4x[10.sup.4]/32
10 1.8x[10.sup.5]/62.1 6.1x[10.sup.4]/21
11 3.8x[10.sup.5]/82.6 7.1x[10.sup.4]/15.4
12 1.2x[10.sup.5]/89.9 1.1x[10.sup.4]/8.1
13 2.1x[10.sup.4]/55.3 5.9x102/1.6
14 1.3x[10.sup.5]/86.7 2x[10.sup.4]/13.3
15 9.4x[10.sup.4]/80.3 1.7x[10.sup.4]/14.5
16 3.1x[10.sup.5]/75 1.7x[10.sup.4]/4.1
17 6.9x[10.sup.4]/94.5 2.2x[10.sup.3]/3
18 4.9x[10.sup.4]/46.7 1.7x[10.sup.4]/16.3
19 - -
20 - -
21 - -
22 - -
23 - 3.9x[10.sup.4]/17.3
24 - 1.7x[10.sup.4]/9.7
25 - 3.1x[10.sup.4]/10.7
26 - 7.1x[10.sup.4]/18.8
27 1.3x[10.sup.5]/33.5 -
28 1.7x[10.sup.5]/32 -
[p.sub.i] 0.43 0.11
Part [MATHEMATICAL [MATHEMATICAL
EXPRESSION NOT EXPRESSION NOT
REPRODUCIBLE IN REPRODUCIBLE IN
ASCII] ASCII]
[??]
No. [mm.sup.3]/% [mm.sup.3]/%
1 - -
2 - -
3 - -
4 - -
5 - 5.2x[10.sup.3]/9.3
6 - 9.9x[10.sup.4]/45
7 - -
8 - -
9 - -
10 - -
11 - -
12 - -
13 - -
14 - -
15 - -
16 - -
17 - 1.7x[10.sup.3]/2.3
18 - -
19 - 7.9x[10.sup.4]/42
20 - 6.7x[10.sup.4]/42.5
21 - 1.2x[10.sup.5]/45.8
22 - 1.4x[10.sup.5]/45.9
23 - 7.9x[10.sup.4]/35.3
24 - 6.7x[10.sup.4]/38.3
25 - 1.2x[10.sup.5]/41
26 - 1.4x[10.sup.5]/37.2
27 2x[10.sup.3]/0.5 -
28 2.5x[10.sup.3]/0.5 -
[p.sub.i] 0.01 0.16
Part [MATHEMATICAL [MATHEMATICAL
EXPRESSION NOT EXPRESSION NOT
REPRODUCIBLE IN REPRODUCIBLE IN
ASCII] ASCII]
No. [mm.sup.3]/% [mm.sup.3]/%
1 - -
2 - 7.7x[10.sup.4]/42.8
3 - -
4 - -
5 - -
6 - -
7 - -
8 - -
9 - -
10 - -
11 - -
12 - -
13 - 1.5x[10.sup.4]/39.5
14 - -
15 - -
16 - 8.7x[10.sup.4]/21
17 - -
18 - 3.4x[10.sup.4]/33.1
19 - -
20 - -
21 - -
22 - -
23 -P1 -
24 - -
25 - -
26 - -
27 2.1x[10.sup.5]/57 -
28 2.8x[10.sup.5]/52.5 -
[p.sub.i] 0.04 0.05
Part [MATHEMATICAL [MATHEMATICAL
EXPRESSION NOT EXPRESSION NOT
REPRODUCIBLE IN REPRODUCIBLE IN
ASCII] ASCII]
No. [mm.sup.3]/% [mm.sup.3]/%
1 7.2x[10.sup.3]/3 -
2 5.5x[10.sup.3]/3.1 2.5x[10.sup.4]/ 13.9
3 3.4x[10.sup.3]/1.2 -
4 3.5x[10.sup.3]/2.7 -
5 - -
6 - 1.2x[10.sup.5]/ 54.5
7 2.2x[10.sup.3]/7.3 -
8 1.9x[10.sup.3]/11.2 -
9 1.7x[10.sup.4]/22.7 -
10 4.7x[10.sup.4]/16.2 -
11 1.3x[10.sup.4]/2.8 -
12 3.4x[10.sup.3]/2.5 -
13 9.6x102/2.5 -
14 3.9x[10.sup.3]/2.6 -
15 6.2x[10.sup.3]/5.3 -
16 5,3x[10.sup.3]/1.3 -
17 - -
18 4.6x[10.sup.3]/4.4 -
19 - 1.1x[10.sup.5]/58
20 - 9.1x[10.sup.4]/57.5
21 - 1.4x[10.sup.5]/54.2
22 - 1.7x[10.sup.5]/54.1
23 - 1.1x[10.sup.5]/47.4
24 - 9.1x[10.sup.4]/52
25 - 1.4x[10.sup.5]/48.6
26 - 1.7x[10.sup.5]/43.7
27 3.18x[10.sup.4]/9 -
28 8x[10.sup.4]/15 -
[p.sub.i] 0.03 0.18
Table 5
Parts' DF theoretical and statistical machining times
Part No. Part's DF machining theoretical times
[T.sup.T.sub.m], h
[T.sub.2.1] [T.sub.2.2] [T.sub.2.3]
1 0.2 1.7 0
2 0.1 2.8 0
3 0.2 2.2 0
4 0.2 2.3 0
5 0.1 0.7 0
6 0 0 0
7 0.1 0.5 0
8 0.1 0.3 0
9 0.1 2.5 0
10 0.2 6 0
11 0.3 6.9 0
12 0.2 1.2 0
13 0.1 0.1 0
14 0.2 2.1 0
15 0.1 1.8 0
16 0.1 1.8 0
17 0.1 0.3 0
18 0.1 1.8 0
19 0 0 0
20 0 0 0
21 0 0 0
22 0 0 0
23 0 4 0
24 0 1.8 0
25 0 3.1 0
26 0 6.9 0
27 0.2 0 0.1
28 0.2 0 0.1
Part No. Part's DF machining theoretical times
[T.sup.T.sub.m], h
[T.sub.2.4] [T.sub.2.5] [T.sub.2.6]
1 0 0 0
2 0 0 0.3
3 0 0 0
4 0 0 0
5 0.2 0 0
6 0.9 0 0
7 0 0 0
8 0 0 0
9 0 0 0
10 0 0 0
11 0 0 0
12 0 0 0
13 0 0 0.3
14 0 0 0
15 0 0 0
16 0 0 0.3
17 0.1 0 0
18 0 0 0.3
19 0.8 0 0
20 0.7 0 0
21 0.9 0 0
22 1.1 0 0
23 0.8 0 0
24 0.7 0 0
25 0.9 0 0
26 1.1 0 0
27 0 2.6 0
28 0 3.3 0
Part No. Part's DF machining theoretical times
[T.sup.T.sub.m], h
[T.sub.2.7] [T.sub.2.8] [summation]
[T.sup.T.sub.m]
1 0.2 0 2.1
2 0.2 0.8 4.2
3 0.2 0 2.6
4 0,2 0 2.6
5 0 0 0.9
6 0 1.7 2.6
7 0.1 0 0.7
8 0.1 0 0.4
9 0.4 0 3.0
10 0.8 0 6.9
11 0.3 0 7.5
12 0.2 0 1.5
13 0.1 0 0.6
14 0.2 0 2.4
15 0.2 0 2.2
16 0.2 0 2.4
17 0 0 0.5
18 0.2 0 2.4
19 0 1.6 2.4
20 0 1.5 2.2
21 0 1.9 2.8
22 0 2 3.0
23 0 1.6 6.3
24 0 1.5 4.0
25 0 1.9 5.9
26 0 2.0 10
27 0.6 0 3.3
28 1.1 0 4.5
Part No. Part's DF statistical machining times
[T.sup.S.sub.m], h
[T.sub.2.1] [T.sub.2.2] [T.sub.2.3]
1 0.1 2.5 0
2 0.1 1.9 0
3 0.2 3 0
4 0.1 1.4 0
5 0.1 0.6 0
6 0 0 0
7 0.1 0.4 0
8 0.1 1.4 0
9 0.8 0.8 0
10 0.2 3 0
11 0.2 4.6 0
12 0.1 1.4 0
13 0.1 0.4 0
14 0.1 1.6 0
15 0.1 1.2 0
16 0.2 4.2 0
17 0.1 0.8 0
18 0.1 1.1 0
19 0 0 0
20 0 0 0
21 0 0 0
22 0 0 0
23 0 2.3 0
24 0 1.9 0
25 0 3 0
26 0 3.8 0
27 0.2 0 0.1
28 0.2 0 0.1
Part No. Part's DF statistical machining times
[T.sup.S.sub.m], h
[T.sub.2.4] [T.sub.2.5] [T.sub.2.6]
1 0 0 0
2 0 0 0.5
3 0 0 0
4 0 0 0
5 0.2 0 0
6 0.5 0 0
7 0 0 0
8 0 0 0
9 0 0 0
10 0 0 0
11 0 0 0
12 0 0 0
13 0 0 0.5
14 0 0 0
15 0 0 0
16 0 0 0.5
17 0.3 0 0
18 0 0 0.5
19 0.4 0 0
20 0.4 0 0
21 0.5 0 0
22 0.6 0 0
23 0.5 0 0
24 0.4 0 0
25 0.5 0 0
26 0.6 0 0
27 0 0.3 0
28 0 0.4 0
Part No. Part's DF statistical machining times p
[T.sup.S.sub.m], h
[T.sub.2.7] [T.sub.2.8] [summation]
[T.sup.S.sub.m]
1 0.3 0 2.9 0.8
2 0.3 0.2 3.6 1.2
3 0.4 0 3.4 0.8
4 0.2 0 1.7 1.6
5 0 0 0.9 1
6 0 1.0 1.5 1.7
7 0.1 0 0.5 1.4
8 0.2 0 1.7 0.3
9 0.1 0 1.0 2.9
10 0.3 0 3.4 2.1
11 0.4 0 5.1 1.5
12 0.8 0 1.7 0.9
13 0.1 0 1.1 0.5
14 0.2 0 1.9 1.3
15 0.2 0 1.5 1.4
16 0.3 0 5.2 0.5
17 0 0 1.2 0.4
18 0.1 0 1.9 1.3
19 0 1 1.4 1.7
20 0 0.9 1.3 1.7
21 0 1.1 1.6 1.7
22 0 1.2 1.8 1.7
23 0 1. 3.8 1.7
24 0 0.9 3.2 1.3
25 0 1.2 4.7 1.3
26 0 1.3 5.8 1.7
27 0.3 0 0.8 4.2
28 0.4 0 1 4.5
Table 6
The statistical average [p.sub.i] of DF
DF Statistical
average [p.sub.i]
2.1 0.42
2.2 0.11
2.3 0.01
2.4 0.16
2.5 0.04
2.6 0.05
2.7 0.03
2.8 0.18