JP3301122B2 - Leveling production control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production management method for leveling production varieties, and more particularly to a line instruction for leveling a production ratio when a lot is produced in a line for multi-product production. It relates to a suitable production management method.

[0002]

2. Description of the Related Art In general, in a processing line for an engine or the like that performs multi-product production, a production management method is employed in which a target production amount, that is, a production ratio is controlled and an overall production ratio is leveled.

In such a case, a leveling table as shown in FIG. 7 is used. In the figure, the leveling table for producing parts of three types, A, B, and C, such that the target production amount is A: B: C = 102: 206: 297 (1) is shown. An example is shown. By the way, in the figure, A = 1... (2) B = 2... (3) C = 3... In the order given, the line designation of the production type is performed. When the line reaches the rightmost column, the line is changed to return to the leftmost column, and this is repeated. A line instruction is issued to return to the top row and left column again. In this line instruction, the production quantity is one for each instruction of a part type, and as long as the production is performed according to this leveling table, the cumulative production ratio is calculated by the formula ( It is designed to approximate the ratio of 1). In other words, as long as this leveling table is used, it is possible to surely produce the product or part at the target ratio by protecting and instructing the specified product type as it is.

[0004]

Since the conventional production management method is configured as described above, the production ratio can be efficiently leveled when individual products are produced. However, depending on the parts that are produced in multiple types, it is more efficient to perform lot production in which a plurality of the same parts are produced together.In some cases, it is necessary to equalize the production ratio of multiple types while producing lots. is there. In the case of performing lot production, since production is performed for each predetermined number of lots, the number of productions needs to be managed by a multiple of this number of lots. Therefore, it is impossible to use a leveling table in the conventional production management method, and a leveling method of a production ratio suitable for lot production has been required.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a production management method capable of leveling the production ratio of products to be produced in lots.

[0006]

In order to achieve the above object, the present invention provides a first step of determining a target ratio of a target production amount of a plurality of types to be produced in lots to a target total production amount; A second process of obtaining a first approximate production amount smaller than the target production amount and a second approximate production amount larger than the target production amount when lot production is performed; A third step of obtaining an approximate total production amount in each of all combinations of the second approximate production amounts as combination candidates, and an approximate ratio of the approximate production amount to the approximate total production amount for each of the approximate production amount combination candidates. A fourth step of obtaining, a fifth step of obtaining a deviation of the approximate ratio from the target ratio for each combination candidate of the production amount, and a sixth step of obtaining a maximum value of the deviation for each combination candidate If, there is provided a leveling method of production control and a seventh step of selecting a combination candidates of each cultivar maximum value of the difference is minimum as the optimum approximation production.

[0007]

In the above means, the target total production amount of the target production amounts of a plurality of types produced in lots in the first step, that is, the target ratio to the total production amount of all types, is determined for each type. When each kind is produced in lots in the process, a first approximate production quantity smaller than the target production quantity and a second approximate production quantity larger than the target production quantity are obtained. All combinations of the approximate production amount and the second approximate production amount are determined as the combination candidates of the respective varieties, and the approximate total production amount is calculated for each combination. In the fourth step, the approximate production amount In a fifth step, an approximate ratio with respect to the approximate total production amount is determined, and in a fifth step, a deviation of the approximate ratio with respect to the target ratio for each product type for each combination of the production amounts is determined. Said combination candidate obtains a maximum value of the deviations for each, selecting a combination candidates of each cultivar maximum value of the deviation in the seventh step is minimum as the optimum approximation production in.

That is, first, an approximate production amount that is close to the target production amount and a multiple of the number of lots is selected for each product type. Then, in the combination of these approximate production amounts, the production amount in the case of performing the leveled production is compared with the production amount based on the target production amount, and the production instruction is performed at the approximate production amount closest to the target production amount. I do.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a flowchart for realizing a production management method according to one embodiment of the present invention.

As shown in FIG. 1, in order to equalize the production ratio in lot production, first, in step S
It is necessary to set the number (N) of types of parts to be produced in 1.

Next, in step S2, a target production amount S (i) of each component is set. Where i
Represents the type of component, i = 1, 2, 3,..., N. In addition, the production quantity R (i) per lot of each component is set as the number of lots. Again, i represents the type of component. When the initial setting is completed as described above, the process proceeds to the next step S3.

Before starting the description of step S3, an outline of production management in this embodiment will be described.

In general, the production amount used for leveling the production ratio can be obtained from the least common multiple of the number of lots of each production type. It is rare that practically used numbers can be obtained. Therefore, it is actually necessary to use each production amount as an approximate value.

Therefore, first, it is necessary to first find the optimum approximate production amount, and based on this, the production amount is leveled in production management.

In this case, it is necessary to determine that the approximate production amount that has been proposed as a candidate is the optimal approximate production amount. In this embodiment, the “MIN-MAX principle” is applied, and the optimal candidate value S1 (i , K *) are set as approximate production quantities. This is the lot production volume that is closest to the target production volume.
* Indicates a candidate value smaller than the target production amount by 1, and a candidate value larger than the target production amount by 2.

Then, each candidate value S1 (j, k
Regarding *), the approximate total production amount TT (j) is obtained for j (= 2 Nth ways) of all the combination candidates. This can be obtained by adding the candidate values of each type for all types.

Further, the approximate ratio SD (i, k) of each approximate production amount S1 (i, k *) to the approximate total production amount TT (j).
*) This is executed based on the following formula: SD (i, k *) = S1 (i, k *) / TT (j) (5)

The difference is compared with the target ratio of the actual target production amount S (i) to the target total production amount T. As a result, the target ratio of the approximate ratio when the approximate production amount is performed for each combination candidate Is obtained.

Next, the maximum deviation MAX (j) is searched for among the combinations, and the maximum deviations MAX (j) among the j combinations are compared.

There are a total of 2 N powers. The smallest one of these is SMIN = MIN (MAX
(J)), the number j of the selected combination candidate is j *, and the approximate production amount S1 (i, k *) of the j * -th combination candidate is the optimal approximate production amount, that is, the final production ratio. To

From the above viewpoint, the processing after step S3 will be described. In step S3, the target total production amount T is obtained from the sum of the target production amounts S (i) of the i types.

Further, for each type, the target production amount S (i)
Is determined as an integer value with respect to the lot production amount R (i). This is performed based on the following formula: X (i) = int (S (i) / R (i)) (6) Incidentally, int defines an integer.

Next, based on the obtained magnification, approximate production amounts S1 (i, 1) and S1 (i, 2) are obtained for each product type. Incidentally, the approximate production amount S1 (i, 1) corresponds to a production amount smaller than the target production amount S (i), and S1 (i, 2) corresponds to a production amount larger than the target production amount S (i). This is represented by the following equation: S1 (i, 1) = X (i) * R (i) (7) S1 (i, 2) = X (i) * R (i) + R (i) (8) It is performed based on. Then, the search proceeds with the approximate production amounts S1 (i, 1) and S1 (i, 2) as candidates for the optimal approximate production amount of each type i. By the way, the approximate production amounts S1 (i, 1) and S1
It goes without saying that the following relationship has been established between (i, 2).

S1 (i, 1) ≦ S (i) ≦ S1 (i, 2) (9) Now, for each of the i types, S (i) = X (i) * R (i) + Y (I) ... (10) Here, Y (i) is a deviation between the target production amount and the approximate production amount. This is, of course, in the relationship of 0 ≦ Y (i) <R (i) (11).

When 0 ≦ Y (i) <R (i) / 2 (12), the following equation is satisfied: SS (i) = X (i) * R (i) (13) When (i) / 2 ≦ Y (i) <R (i) (14), SS (i) is such that SS (i) = (X (i) +1) * R (i) (15) ). Where SS
(I) is one of the candidates for the optimal approximate production amount, which is an intuitively conceivable production amount. By the way, this SS (i)
Are obtained for the purpose of comparison, and are items that do not necessarily need to be obtained in implementing the present invention.

Next, the target ratio ST (i) of the target production amount S (i) of each type to the target total production amount T is calculated based on the following calculation: ST (i) = S (i) / T (16) Ask. Then, when the above processing ends, the flow shifts to step S4.

In the next step S4, the approximate production amounts S (i, 1), S (i, 2) corresponding to each of the i kinds of varieties.
TT (j) = S1 (1, k *) + S1 (2, k *) +... + S (N) for all combinations (j = 2 to the Nth power) , K *) (17). Here, k * is 1 or 2.

Next, depending on the combination candidate of each type, S
2 (j, i) is replaced with S1 (i, 1) and S1 (i, 2), and approximate production amount S corresponding to j possible combinations
2 (j, i) can be formed, and then the ratio of the approximate production amount S2 (j, i) to the approximate total production amount TT (j) is defined as the approximate ratio SD (i, k *). , K *) = S2 (j, i) / TT (j) (18) Further, the obtained approximate ratio S
Deviation SD of D (i, k *) with respect to target ratio ST (i)
T is calculated based on the following equation: SDT (i, k *) = ABS (ST (i) -SD (i, k *)) (19) Incidentally, ABS indicates an absolute value.

Then, the processing shifts to the next step S5, in which the maximum value of the deviation SDT (i, k *) in the combination candidates (j ways) of the approximate production amounts of all varieties is searched, and this is defined as MAX (j). I do.

Next, the process proceeds to step S6 to select the smallest one of MAX (j) among the combination candidates of all varieties. This is performed by a search of SMIN = MIN (MAX (j)) (20). In this case, j is j *, and the combination number is the optimal approximate production amount. As a result, it is required that the optimum approximate production amount of each type is obtained from the j-th combination candidate. This optimum approximate production amount is represented by S2 (j *, i).

When the above processing is completed, the process proceeds to step S7, where the data (integer) of the optimum approximate production amount S2 (j *, i) / R (i) obtained for each product type is the same as the conventional one. Leveling is performed based on the method, and a leveling table for each lot of each product is created.

Then, the process goes to step S8 to multiply the lot in the lot leveling table by the lot R (i) to obtain the production quantity corresponding to the type i of each kind, that is, the production quantity for each kind. A final leveling table that is continuous for a number R (i) is obtained.

A specific procedure in the case where the above embodiment is specifically implemented will be described with reference to FIG. In this example, there are three types of products, i = 1
~ 3.

Here, the target production amounts corresponding to the respective production ratios are S (1) = 102 (21) S (2) = 206 (22) S (3) = 297 (23) It is assumed that the total production amount is T = 605 (24). Further, it is assumed that each production lot of each production type is R (1) = 10 (25) R (2) = 8 (26) R (3) = 10 (27)

Under the above conditions, approximate production amounts, that is, optimum candidate values are obtained. First, X (i) is obtained based on equation (5).

X (1) = int (102/10) = int (10.2) = 10 (32) X (2) = int (206/8) = int (25.75) = 25 ... (33) X (3) = int (297,10) = int (29.7) = 29 (30) Then, based on this X (i), the approximate production is calculated according to the equations (6) and (7). S (1,1) = 10 × 10 = 100 (31) S (2,1) = 8 × 25 = 200 (32) S (3,1) = 10 × 29 = 290 (33) Is obtained as an approximate production amount S (i, 1), and S (1, 2) = 10 × (10 + 1) = 110 (34) S (2, 2) = 8 × (25 + 1) = 208 (35) S (3,2) = 10 × (29 + 1) = 300 (36) is obtained as the approximate production amount S (i, 2). The above results naturally satisfy Expression (8). That is, 100 ≦ 102 ≦ 110 (37) 200 ≦ 206 ≦ 208 (38) 290 ≦ 297 ≦ 300 (39)

Now, according to equation (9), Y
Try to find (i).

Y (1) = 102−100 = 2 (40) Y (2) = 206−200 = 6 (41) Y (3) = 297−290 = 7 (42) Of course, the result is Formula (10) is satisfied.

Then, the above results are obtained by using the equations (11) and (1).
Evaluate based on 3). As a result, the relationship of Expression (11) holds for Y (1). Therefore, equation (12)
As a result, SS (1) = 100 (43) is obtained. On the other hand, since the relationship of Expression (13) holds for Y (1) and Y (5), from Expression (14), SS (2) = 208 (44) SS (5) = 300 (45) Is obtained. This is an amount corresponding to an approximate production amount that can be obtained intuitively.

Here, the ratio of each production amount to the total production amount 605 is obtained based on the equation (15).

ST (1) = 16.89 (46) ST (2) = 34.05 (47) ST (3) = 49.09 (48) Then, S (1,1)- S (3,1) and S (1,
2) All combinations of S (3, 2) are arranged as shown in FIG. This corresponds to S1 in FIG.
The items of (1, k *) are S1 (1, k *) to S1 (3, k
*) Are as indicated respectively.

In this case, each combination has a total of j = 2 ³ = 8 (49).

Next, according to equation (16), the approximate total production amount T in each combination of the optimal approximate production amounts
T (1) to TT (8) are obtained. This is as shown in the item of TT in FIG.

Next, the approximate ratio SD (i, k *) of each candidate value to each of the approximate total production amounts TT (1) to TT (8) is calculated according to the equation (17). The result obtained as described above is as shown in the item indicated by SD (i, k *) in FIG.

Further, according to equation (18), the deviation between the ratio of the target production amount S (i) of each type to the total production amount T and the ratio to the approximate total production amount TT (j) when the optimal approximate production is performed is obtained. . This is as shown in SDT (1, k *) to SDT (5, k *) in the item of SDT (i, k *) in FIG.

Next, the maximum value of the difference is extracted as MAX (j) while referring to the deviation SDT (i, k *) item in each of all the combinations of the approximate production amounts. This is written out in the item of MAX (j) in FIG.

Next, based on the relationship of equation (19), MA
The minimum one is extracted from X (j), and SM (FIG. 2) is extracted.
Write in the IN entry. This is SMIN = 0.15 (50). Then, j at this time is j = 1 (51).

By the way, according to the intuitive optimal solution obtained from the equations (7) to (15) , j = 4 (52).

The approximate production quantities of the obtained varieties are as follows: S2 (1,1) = 100 (53) S2 (1,2) = 200 (54) S2 (1,3) = 290 (55) S2 (1,1) / 10 = 10 (56) S2 (1,2) / 8 = 25 (57) S2 (1,3) / 10 = 29 (58) Based on the data obtained in this way, leveling for each product type is first performed by a known method.
As a result, a lot leveling table as shown in FIG. 3 can be obtained. Further, by multiplying the number of lots for each product type, a leveling table in units of numbers as shown in FIG. 4 can be obtained.

Incidentally, in FIGS. 3 and 4, five production varieties are represented by numbers, such as i = 1... (59) i = 2... (60) i = 3. In addition, as shown in FIG. 4, the line instruction is performed in units of one product type. The processing is performed for each product type in the order indicated from the uppermost row of the left column toward the right, and when the rightmost column is reached, the row is changed to return to the leftmost column, and this is repeated. When the production of the variety specified in the fifth column from the left is completed, the process returns to the top left row again. In this line designation, the production quantity is in units of one unit per designation of one kind of component, and therefore, for each kind, the numbers of the kinds consecutive for the number of lots are arranged. As long as the production is performed in accordance with this leveling table, the cumulative production ratio should be similar to the production quantity ratio of each product shown in Expressions (21) to (25) at any point during the production. Has become. Incidentally, this line designation is not limited to one unit, but may be performed for each product and one lot, for example, with the leveling table shown in FIG. 3 as it is, so that the leveling table can be simplified.

In the above example, since the number of lots and the number of types are small, the optimal solution (j = 1) and the intuitive solution (j =
Although there is no significant difference from 4), a difference occurs when the number of lots and the number of varieties increase. Such a case will be described below. In this example, there are five types of products, i
= 1-5.

Here, the target production amounts corresponding to the respective production ratios are as follows: S (1) = 448 S (2) = 1006 S (3) = 1216 S (4) = 1538 S (5) = 3026 , The total production volume is T = 7235. In addition, each production lot of each production type has R (1) = 50 R (2) = 30 R (3) = 50 R (4) = 40 R (5) = 50.

When a similar calculation is performed using these values, S2 (17,1) = 450 S2 (17,2) = 990 S2 (17,3) = 1200 S2 (17,4) = 1520 S2 (17,5) ) = 3000. According to an intuitive solution, S2 (26,1) = 450 S2 (26,2) = 1020 S2 (26,3) = 1200 S2 (26,4) = 1520 S2 (26,5) = 3050. This is shown in FIG.

As described above, also in the above example, the present embodiment
The difference between the calculation method of the example and the intuitive solution appears.
It is understood that the law complies with the production ratio.

[0055]

By giving line instructions based on the leveling table obtained as described above, it is possible to protect production lots of all types while minimizing variations in the total production quantity, and furthermore, all types in all production processes. Leveling of production quantity can be realized.

Although the case of bringing the step of obtaining the target ratio ST (i) last in the order of the calculation in step S3 of the above embodiment is illustrated, this calculation item is the target production quantity S (i). ) And the total production quantity T are computational items that can be executed at any time as long as the total production quantity T is known. Incidentally, in the claims, this step is described as the first step, but the step may be performed at any time before the element based on the calculation result is used.

[0058]

As described above, according to the present invention, when producing lots of many kinds, a plurality of optimum approximate production quantities are obtained for each kind, and a deviation from an ideal production ratio for each kind in each combination. It is set to select a combination of production quantities that minimizes the maximum value of this deviation, so that it is possible to realize an optimal approximate production quantity for the actual production quantity, As a result, it is possible to reduce the inventory amount even in the case of a lot production in which it is difficult to adjust the inventory amount corresponding to the post-processing, and there is an effect that the process can be rationalized.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a production management method according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a production management method according to the embodiment.

FIG. 3 is an example of a leveling table obtained by the present embodiment, particularly a leveling table indicated in lot units.

FIG. 4 is an example of a leveling table obtained by the present embodiment, in particular, a leveling table shown for each production unit.

FIG. 5 is an explanatory diagram of the production management method according to the embodiment;
In this example, another example is used.

FIG. 6 is an explanatory diagram of an example of a leveling table based on a conventional method.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G06F 17/60 B23Q 41/08 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A leveling management method for leveling products to be produced in multi-product mixed production, wherein a target ratio of a target production amount of a plurality of types produced in lots to a target total production amount is determined. One step, a second step of obtaining a first approximate production amount smaller than the target production amount and a second approximate production amount larger than the target production amount when lot production of each type is performed; A third step of obtaining an approximate total production amount in each of all combinations of the first approximate production amount and the second approximate production amount as combination candidates, and the approximation of the approximate production amount for each of the approximate production amount combination candidates. A fourth step of determining an approximate ratio to the total production;
A fifth step of obtaining a deviation of the approximate ratio from the target ratio for each combination of the production amounts, a sixth step of obtaining a maximum value of the deviation for each combination candidate, and a maximum value of the deviation being minimized A seventh step of selecting a combination candidate of each kind as an optimal approximate production amount.