Title:
ARRANGEMENT FOR PLANNING AND MONITORING A PRODUCTION PROCESS
United States Patent 3703630


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
Application Number:
05/072331
Publication Date:
11/21/1972
Filing Date:
09/15/1970
Assignee:
FRANZ GELDER
Primary Class:
Other Classes:
313/510
International Classes:
G07C3/12; (IPC1-7): H01J63/04; G06K15/18; H01J1/63
Field of Search:
340/324,166EL 307
View Patent Images:
US Patent References:
3531795BAR-TYPE DISPLAY1970-09-29Gassler
3469252INTEGRATED BAR GRAPH DISPLAY HAVING INTERRUPT CONTROL1969-09-23Bet
3376452Circular electroluminescent display device1968-04-02Lally
3351937Data-display apparatus1967-11-07Spens
3328790Display devices1967-06-27Rhodes
3327163Electroluminescent bar graph indicator1967-06-20Blank
3205403Electroluminescent display systems1965-09-07Schwertz
3149281Electroluminescent voltage measuring device1964-09-15Lieb



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 X1, X2 . . . Xn with the aid of m production facilities V1, V2 . . . Vm. 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 X1 and X2 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 W1, W2 . . . Wm and n blast furnaces H1, H2 . . . Hn 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.