U.S. patent number 3,703,630 [Application Number 05/072,331] was granted by the patent office on 1972-11-21 for arrangement for planning and monitoring a production process.
Invention is credited to Franz Gelder.
United States Patent |
3,703,630 |
Gelder |
November 21, 1972 |
ARRANGEMENT FOR PLANNING AND MONITORING A PRODUCTION PROCESS
Abstract
An indicator board for visually displaying values obtained by
linear programming, such as the degree of utilization of
facilities, production output of different units, etc., comprises a
board having luminescent strips activated by input signals to
extents corresponding to values to be displayed. Symbols
designating products and operating units are provided in different
fields of the board adjacent to the corresponding strips.
Inventors: |
Gelder; Franz (Salzburg,
OE) |
Family
ID: |
3608069 |
Appl.
No.: |
05/072,331 |
Filed: |
September 15, 1970 |
Foreign Application Priority Data
|
|
|
|
|
Sep 15, 1969 [OE] |
|
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A8732/69 |
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Current U.S.
Class: |
700/83;
313/510 |
Current CPC
Class: |
G07C
3/12 (20130101) |
Current International
Class: |
G07C
3/00 (20060101); G07C 3/12 (20060101); H01j
063/04 (); H01j 001/63 (); G06k 015/18 () |
Field of
Search: |
;340/324,166EL ;307/311
;313/108 ;250/217 ;235/151.3 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Morrison; Malcolm A.
Assistant Examiner: Wise; Edward J.
Claims
That which is claimed is:
1. A system for planning and monitoring a production process
comprising an indicator board having a first and a second field,
each of said fields including light-emissive signal strips having
an area of emission of controllable extent responsive to input
signals, programmed computer means adapted to derive output signals
in response to production data and a computer program composed in
accordance with a production plan, a control unit connected to
receive said output signals and to derive said input signals for
controlling the various strips, a plurality of product symbols in
said first field designating predetermined products of said
process, said strips in said first field including a group of
strips corresponding to each of said symbols, first means connected
to said control unit for applying to a first strip of said group an
input signal representing the quantity of the corresponding product
multiplied by the marginal cost thereof and to a second and a third
strip of said group input signals representing the nominal and the
real marginal costs, respectively, of said corresponding product, a
plurality of production unit symbols in said second field, a signal
strip in said second field corresponding to each of said production
unit symbols, and second means connected to said control unit for
supplying to the signal strips of said second field signals
characterizing the planned operation of said production units.
2. A system according to claim 1, in which said signal strips
extend parallel to a predetermined direction, and said fields have
graduations therein indicating distance along said direction.
3. A system according to claim 2, comprising an exchangeable scale
and means for attaching said scale to said board in coordination
with said graduation.
4. A system according to claim 1, comprising an auxiliary signal
strip for optically designating predetermined ones of said product
symbols.
5. A system according to claim 4, comprising a linear identifying
means extending parallel to said signal strips and adjustable
perpendicularly thereto.
6. A system according to claim 4, comprising an auxiliary signal
strip extending perpendicularly to the signal strips of said first
field for identifying selected ones thereof.
7. A system according to claim 6, in which said auxiliary signal
strip is a signal strip having an area of emission of controllable
extent.
8. A system according to claim 1, for a plant comprising a
plurality of shifts, in which the strips of said second field are
combined to form groups having a plurality of strips corresponding
to said shifts.
9. A system according to claim 1, in which the individual strips of
a group are distinguished by different physical structure.
10. A system according to claim 1, in which the individual strips
of a group are distinguished by different colors.
11. A system according to claim 1, comprising a linearly extending
identifying means in said second field extending perpendicularly to
said strips and adjustable parallel thereto.
12. A system according to claim 1, comprising means for digitally
indicating the value of at least one of the digitally displayed
signals.
13. A system according to claim 1, in which said light-emissive
signal strips are electroluminescent strips.
Description
FIELD OF THE INVENTION
This invention relates to the planning and monitoring of production
processes.
BACKGROUND OF THE INVENTION
It is imperative in modern industrial enterprises that the
production can be planned in advance and monitored on a more or
less long-term basis to enable optimal adherence to production
schedules and rapid adaptation to the marketing situation. This is
usually done with the aid of known operation plans, which can be
produced with the aid of computers. Also, it is desirable to have a
clear representation of the results and of the degree of conformity
with the plans so as to make possible monitoring in a simple
manner.
Production data are reproduced or displayed by several known
methods in use at the present time. One method consists in cutting
paper strips corresponding to the magnitudes of the data to be
represented and to attach them to an indicator board. Another
method uses magnetic rings which are attached to a metal sheet
board. The representation of a magnitude by a strip of
corresponding length may also be obtained with the aid of strips
wound onto drums and which are pulled out to the required length
into guide rails provided on an indicator board. However, none of
these methods is suitable for cooperation with computers, which are
extensively used nowadays for production planning, cost calculation
and the like. Specifically, the use of paper strips cut to
different lengths is time-consuming and complicated, and in
addition, all the methods referred to are liable to errors
resulting from the manual steps contained therein.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the invention to make possible a clear and
simple optical display of industrial production data on an
indicator board which may be controlled directly from a computer. A
computer may be programmed to obtain any desired functions of input
data supplied thereto. The program fed to the computer may include
a mathematic model for optimizing the production process involving
various production data, such as product types and quantities,
marginal cost of each product, data describing production
facilities and so on. This is achieved according to the invention
by means of an indicator board divided into a pair of fields, one
field having therein product symbols designating products to be
obtained and corresponding to each symbol a group of light-emissive
signal strips, for instance, differently colored strips, such as
electroluminescent strips, adapted to be activated for emitting
light over variable lengths thereof. One of the strips of the group
is adapted for indicating the quantity of the corresponding product
multiplied by its marginal cost including the fixed cost and a pair
of further strips are adapted for indicating the nominal or desired
and the actual marginal cost. The other field has therein
production unit symbols designating different production units and
for each such symbol at least one strip for indicating the planned
degree of utilization thereof in production. The strips are
controlled by a computer which has been fed with a program for
solving said mathematical model for optimizing the production
process obtained by so-called linear programming including the
available data characterizing the production plant and equipment
and other facilities and economical conditions for deriving output
signals indicative of the operation of a production unit, e.g.,
representing quantities of products, utilization of production
facilities, etc. These output signals are derived in the computer
from the input data supplied thereto by the solving of a system of
equations in accordance with the program. A switching means may be
interposed between the computer and the strips. The luminescent
strips may be of different types and be arranged for comparison
with exchangeable scales. Means may be provided for indicating a
grouping together of pluralities of luminous strips.
The computer can be integrated with the arrangement but may also be
provided at an entirely different location of a production plant or
even at appreciable distance therefrom and connected therewith via
a data transmission system.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows an indicator board representing an embodiment of the
invention; and
FIG. 2 shows a part of a modified form of the board.
DESCRIPTION OF EMBODIMENTS
The indicator board shown in FIG. 1 is subdivided into a pair of
fields 1 and 2. Provided in the left-hand field 1 are symbols 6
designating different products and corresponding to each product
symbol a group of three light-emissive strips, such as luminescent
strips 3a, 3b, 3c having an area of emission which is controllable
by means of input signals applied to the strips, the extent or
length of the portion of the strip which emits light being, for
example, proportional to the intensity of an applied input voltage.
To facilitate identification, the lowermost strip 3c, which is
adapted to indicate the value of product quantity multiplied by the
marginal cost including the fixed costs is of greater width and/or
differently colored from the other two 3a, 3b, which indicate for
the corresponding product the nominal or desired value and the
actual value of the marginal cost, preferably in per cent of the
price quotations. The field is provided with graduation lines 13 to
make possible easy evaluation of the representation with the aid of
a scale 8. To make possible the application of the arrangement for
all sorts of products, a plurality of scales are provided, from
which a suitable one is selected corresponding to the product in
question. Often it is required to group together several products
or their corresponding represented values and to this purpose a
ruler 7 or an auxiliary light-emissive strip 12 may be
provided.
The right-hand field has provided therein symbols 5 designating
production units, such as production plant locations, shops,
offices, or the like, as well as light-emissive strips such as 4a,
4b, and 4c coordinated therewith. For an enterprise which works in
shifts, such as three shifts, a subdivision into a corresponding
number of strips representing the individual shifts is suitable.
These light-emissive strips indicate the degree of utilization of
the production facilities of the enterprise, for instance, of
machines or manually operating units, preferably in per cent. For
greater clarity, a further ruler 9 may be provided, which can be
adjusted in a position corresponding to a certain percentage, or a
number of luminescent strips may be provided in spaced arrangement,
one or more of which can be energized to designate desired
percentage values. The luminescent strips may be of the
electroluminescent type referred to in the magazine "Flugwelt" 19
(1967), No. 9, page 638, published by Krausskopf-Flugwelt-Verlag
GmbH, Mainz, Germany, or in the magazine
"Luftfahrttechnik-Raumfahrttechnik," Vol. 13 (1967), No. 11, pp.
276-279, published by VDI Verlag, Duesseldorf, Germany.
The output signals from computer 11 are supplied to a control unit
10, which controls the various luminescent strips of the board.
The control unit 10 may be of any known type suitable for adapting
the output signals of the computer to the kind of input signal
required by the luminescent strips, and has therefore been
indicated only schematically in block form. By way of example, if
the strips require an analog input voltage, the digital output from
the computer may be converted by the control unit into analog form.
Also, the computer may feed address information along with an
output signal indicating to which strip the signal in question
should be supplied and causing the control unit to establish
connection with the corresponding strip.
All types of production data referred to above, as well as a
computer program which has been composed in accordance with the
known rules of production planning and/or a mathematical model for
optimum planning, may be supplied to a computer 11 in which they
are processed to derive output signals.
The production planning of an enterprise gives rise to a problem of
the following type:
The enterprise produces n products X.sub.1, X.sub.2 . . . X.sub.n
with the aid of m production facilities V.sub.1, V.sub.2 . . .
V.sub.m. The term "production facilities" is to be taken in its
broadest sense and includes machines, personnel, raw materials,
intermediate products, electric energy, storage space, transport
vehicle, etc.
Normally, the most important facilities are machines and workers,
which may form organized production units. The capacity of such a
unit is the maximum amount produced in a certain interval.
Usually, it is desired to maximize the overall profit of the
enterprise, which is a function of the quantities and types of
products. For different products, the price includes different
values of the components which together constitute the price
quotation: variable cost, fixed cost and profit. The first two
together form the prime cost and the last two the marginal
cost.
Variable cost includes, for example, the cost of electric energy,
raw materials, proportionate wages, etc. Fixed cost, which
includes, for example, depreciation of equipment, rents,
insurances, fixed wages, etc., remains unchanged regardless of
whether equipment or labor is used productively or not.
As a simple example, assume that two products X.sub.1 and X.sub.2
are manufactured in quantities (so far unknown) of x and y and the
corresponding profits per unit are a and b, respectively. The total
profit is then expressed by the linear equation Z = ax + by; since
the production capacity is limited, both x and y are limited and if
further factors are taken into account, such as the fixed and
variable costs of the products, marketing considerations, etc.,
additional conditions are to be met and new variables are
introduced, such as the degree of utilization of different
facilities. These additional conditions may also be expressed by
equations, e.g., of linear character.
The totality of these equations constitutes an optimum model,
especially a maximum profit model or minimum cost model indicating
how the production should be planned. It is possible to arrive at
values for the several variables by solving the usually very large
number of equations of the optimum model obtained by known linear
programming methods, preferably by means of a computer, to which
there is fed the mathematical program for solving the system of
equations as well as the input data representing the known
properties of the production, such as capacities, profits of
products, fixed costs, marketing considerations, etc.
The methods of obtaining the optimum models and solving the same by
means of computers may be, for instance, of the types described in
one of the following well-known textbooks:
Dorfman-Samuelson-Solow: Linear Programming and Economic Analysis,
New York, 1958
Ferguson-Sargent: Linear Programming, New York, 1958
Manne-Markowitz: Studies in Process Analysis, New York, 1963
The theoretical value of the quantity of a product which has been
obtained by the computer may now be multiplied with the
corresponding marginal cost. This operation can be performed by the
computer, which has already been supplied with information about
the marginal costs of different products. The resulting value may
be represented on a luminescent strip.
The marginal cost value supplied to the computer is, on the one
hand, the so-called planned marginal cost obtained from the planned
cost accounting or from a roughly estimated production program and,
on the other hand, the actual marginal cost which is obtained as
the difference between the effective net product sales and the
product-variable costs. This is done since the quotation prices of
the product arrived at by the cost accounting (with the product
costs calculated by the cost accounting) usually do not correspond
to the established actual product market prices which may differ
also because of competitive grounds. Since, as a general rule, the
product line formed of a number of different products is not
permanent but, because of numerous influencing factors may be, and
rationally should be, varied, it is advantageous--as contemplated
by the invention--to indicate the actual marginal cost per product
as well as its planned marginal cost not only as a mathematical but
also as an optical (i.e., visual) magnitude. If the actual marginal
costs are shown visually to be larger than the planned marginal
cost of the products, an immediate overall visual survey
meaningfully indicates not only the particularly profitable
products, but also those products which, as a general rule, may be
sold cheaper by the difference between the actual marginal cost and
the planned marginal cost or those which, with their already
well-established prices, particularly contribute to the profit
buildup of the enterprise and therefore their production and sale
should be encouraged. The same, but converse considerations apply
for those products whose actual marginal cost is smaller than their
planned marginal cost; a condition which is also visually
recognizable according to the invention. These indications, which
may thus also be represented visually, have a great significance
for the determination of the product line and for market and price
policy considerations. This significance of such indications is
even more intensified by the fact that--based on the marginal cost
values per product supplied to the computer and based on the work
plan per product and further, based on data which are also fed to
the computer and which relate to available production capacities
pertaining to equipment and labor per work station--according to
the invention, it may also be visually shown next to the visual
indication of the production capacity, whether and to what measure
does in a planned production program the production capacity
fulfill the requirements in its entirety and also per operating
work stations for both a single shift and a multiple shift
operation (it is noted that a work plan discloses which work
station is used to make the product and what average production
times are needed for equipment and labor). In this manner, again,
important indications are obtained for future investment policies
since the operational bottlenecks are immediately visually
recognizable in a positive manner. Since on the opposite side of
the exemplarily described arrangement of the invention, not only
the planned and actual marginal cost per product (and thus its
meaningful difference) may be recognized, but there are also
visually shown the absolute magnitudes of each planned product
quantity or actual marginal costs derived from product quantities
calculated and proposed by the computer based on a given optimal
model. Such indications may furnish the management with further
important keys for decision making. Since previously the computer
also calculated from the given program the entire sum of the fixed
costs relating to the operation (that is, the so-called actual
total fixed cost), there is immediately shown not only digitally
but also in a meaningful manner visually, with what type of product
and product quantities (and the marginal costs resulting therefrom)
will the actually present total fixed costs be fully covered. As a
further result, the apparatus described by way of example, visually
and digitally shows to what extent does the total profit of the
enterprise increase if the available production capacities are
fully balanced. Such result is obtained principally because,
subsequent to covering the total actual fixed cost, the excess of
the marginal cost values of the products gives the actual profit of
the enterprise for the planned or computer-calculated optimal
production program. These data are also optically and digitally
visible. Thus, as a result, the invention assists in a particular
manner the product line planning and production planning for a
maximum profit.
The aforenoted considerations thus show the importance of a rapid
indication of the actual and planned marginal cost as well as the
magnitude obtained by multiplying the product quantity by its
marginal cost. It is similarly important to show rapidly the
utilization of operational capacity of the production program which
is either planned in a conventional manner or is calculated by a
computer based on an optimum model.
If the computer, based on the optimum model, calculates the
quantities of the individual products, then, since the
manufacturing steps of the individual products and the production
factors necessary therefor are fixed, the utilization of the
production capacity is determined. The speed of calculation and
also a rapid visual indication of the results is of great
importance since it is then possible to obtain various simulated
programs which are close to reality. In practice, the determination
of the production program is never left solely to the computer, not
even if it works with mathematical optimum models. The reason is
that there are constantly changes in the magnitudes of the
influencing variables so that only a cooperation of the human
spirit (usually taking effect as a result of teamwork of
management), sales and operational leadership, cost accounting and
further operational units, may result in a determination of the
optimum product line and production program by utilizing the
calculating speed and capacity of the computer and further
utilizing suitable rapid visual indicator devices to illustrate the
results automatically which is the purpose and the subject of the
present invention.
In practice, there are thus preponderantly variable simulated
situations which are "played through" mostly as a result of the
teamwork of the departments in charge around the conference table
utilizing a continuously changing quantity of operational data and
accordingly, supplying different data quantities to the computer
(which may be located on or off the premises). Thus, continuously
changing products are often preplanned for production in determined
quantities, because the sales department may have already fixed
orders which have to be fulfilled in any case irrespective of
whether these products are particularly profitable or not. Since
such fixed planned product species and quantities (which may be
determined for example in the course of a conference) are supplied
as a so-called condition in an optimal model, the problem is thus
always to optimize the remainder of the production program, that
is, to optimize the still undecided product species and product
quantities. In such cases, from the product line some preplanned
individual products, based on definite sales considerations are
included in the mathematical model as conditions and thus have an
effect on the remainder of the optimized calculated results.
Thus, since such product line planning and production planning take
place mostly as a teamwork and usually around a conference table,
it is particularly important that a rapid calculating process and
also a rapid optical indication of the results take place. The
speed of obtaining results is not only dependent upon the
calculating speed of the computer, but first of all, upon the type
and extent of the program which, in turn, is dependent upon the
number of the individual calculating steps which are necessarily
tied with the basic mathematical optimum model. By weighing all
circumstances, it may be said that a larger tolerance in the
accuracy of the results is of lesser importance than a smaller
tolerance which latter, however, gives rise to unproportionately
longer calculating times of the computer.
For a solving process in case of a practically still representation
or visual display, a somewhat greater tolerance of the calculator
results. The so-called "transporting method" and thereamong
preferably the so-called "Hungarian Method" is very rapid and may
be relied upon. It requires only one-tenth of the calculating
period compared with other solving processes. The so-called
Hungarian Method, as a variant of the so-called "transporting
method" is described in detail particularly in H. C. Joksch:
Lineares Programmieren, Tubingen, 1965, pp. 159-167.
These considerations illustrate the importance of a rapid display
of nominal and actual marginal costs.
If the computer calculates optimal values of the quantities of
different products, it may be programmed to derive therefrom the
degree of utilization of the corresponding production facilities.
This makes it possible to ascertain if adjustments of the running
program should be made, e.g., it may turn out that one production
unit can do the job originally envisaged for two units.
A visual inspection of the board may indicate that a correction
should be made in the data or the program supplied to the computer,
and the result of such an alteration will then be immediately
visible.
It is clear from the above that not only the maximum profit but
other optimal conditions may be obtained in similar manner. In many
enterprises, such as base material industries, oil shipping and
other transport companies, the counterpart of maximum production
would be optimum transportation of goods. Assume, for instance,
that a company possesses m mines W.sub.1, W.sub.2 . . . W.sub.m and
n blast furnaces H.sub.1, H.sub.2 . . . H.sub.n at different
locations, and the maximum output of the mines and the capacities
of the furnaces are known, as well as the cost of transport from
any mine to any furnace. It is then of importance to find a
transportation plan representing a minimum of cost.
The solution of a model of this type of problem can be found
preferably by means of the aforenoted Hungarian Method, described
in the cited reference. The result is a set of output values from
the computer that may be represented on the indicator board of the
present invention.
The term "production process," as used in the present specification
and claims, is, therefore, to be taken in its broadest sense to
include the production not only of material products but of any
kind of effort or work, such as transportation work.
Since it is possible to feed into a computer programs of widely
varying types, it is easily possible to plan a production program
at short notice and to optimize it in a largely automatic manner
and then to survey the planning process. Specifically, during
important conferences, data of a most varied character can be made
available at short notice and in clearly represented form. In view
of the storage capabilities of the computer, older data can be
obtained easily. All these characteristic features make the
arrangement particularly suitable for conferences, particularly in
view of the fact that it can easily be supplemented with means for
indicating digital values, mechanically or electronically, for
instance, for separate representation of particularly interesting
values, such as the profit.
* * * * *