JP2003280718A - Build-to-order production planning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set an optimum production quantity according to an order-receiving situation, and to set the optimum production quantity even when made-to-order products are brought forward or backward. <P>SOLUTION: A leveling procedure is continuously executed for an N+1-shift and succeeding ones after a fixed shift (N-shift). The quantity for each element is moved forward to the fixed shift by leveling, so that the production quantity after the fixed shift is reduced. When the difference between the total production quantity of products A and B in the fixed shift leveled for each element and the maximum production quantity mab1 continue in a state equal to a predetermined quantity or more by exceeding a predetermined number of times (predetermined shift numbers), the maximum production quantity is revised downward. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a make-to-order production plan creating method for producing a production plan so as to equalize the amount of production within an operating period when an automobile or the like is continuously produced on a production line for each operating period. .

[0002]

2. Description of the Related Art Conventionally, in a production line for continuously producing automobiles as products, the operation is carried out in units of days, operating hours of production equipment, and work system (for example, shift of a day divided into day and night). When allocating the production amount for each period, part of the production amount within this operating period is distributed to other operating periods according to the production amount and type of product, and the production amount is leveled (averaged) comprehensively. The production plan is created accordingly.

As a conventional example of creating a production plan using such leveling, a long-term production plan is gradually changed / added using a medium-term production plan and a short-term production plan, and the daily production amount is averaged. By making it possible to determine the final production amount without rebuilding the production plan from the beginning (see Japanese Patent Application Laid-Open No. 4-302355), or the order-made product with a delivery date is allocated first. By allocating prospective production products after that, delivery delay does not occur,
A method that allows production of a product with no delivery date to be allocated to a portion with excess capacity (JP-A-11-232
No. 344) and the like have been proposed.

[0004]

By the way, in the build-to-order manufacturing system, which produces each time according to the customer's order, regardless of the production plan created by the above-mentioned leveling, the order with the delivery date desired by the customer is In real time, the upper limit of production by the production equipment is also fixed, so in a situation where a large number of order-made products are ordered, the production of prospective products will be delayed. However, since the production volume of the prospective products is also planned for the long term, the long-term production plan is gradually changed / added using the medium-term and short-term production plans as in the above-mentioned conventional example, and the production of one day is completed. By averaging the quantity, allocating the order-made products with delivery dates first, and then allocating the prospective production products, the prospective production products are produced, and the delivery time and production of the make-to-order products can be produced at the same time. It is difficult to make a plan, and it is desirable to be able to make a production plan that can adapt to such situations and improve production efficiency.

The present invention has been made in view of the above circumstances, and an object thereof is to set an optimum production amount according to an order situation.
An object of the present invention is to provide a make-to-order manufacturing plan creation method capable of setting an optimum production amount even when the made-to-order product is moved forward or backward.

[0006]

In order to solve the above-mentioned problems and to achieve the object, the method for creating a make-to-order manufacturing plan of the present invention is
In a method of continuously producing a product on a production line for each operation period and creating a production plan so as to level the production within the operation period, the product is a sequential order product that is sequentially ordered, The provisional setting step of temporarily setting the production plan so that the sequential ordered products are produced in a predetermined operation period, and the production amount in the fixed period that is equal to or more than the predetermined upper limit production amount in the operation period, From the first plan setting step for setting the production plan by leveling in the operation period from the predetermined period to the predetermined period and the fixed period after the fixed period, the same procedure as the temporary setting step and the first plan setting step is performed. By comparing the continuous setting process for setting the production plan after that, the production amount in each operating period set in the continuous setting process, and the upper limit production amount set for each operating period, And a correcting step of correcting the upper limit production.

Further, preferably, in the correction step, the upper limit is set when the difference between the production amount set in a predetermined continuous operation period and the upper limit production amount is a predetermined amount or more and the operation period is a predetermined number of times or more. Correct production.

[0008] Further, preferably, the sequentially ordered product is
It is possible to set the first element and the second element separately according to the characteristics of each product. In the temporary setting step, the production plan of the sequentially ordered product is temporarily set for each element, and in the first plan setting step, Sequentially setting the production plan for each product having one element and the product having the second element by setting the production plan, and setting the production plan for the product in the fixed period based on each production plan. An order receiving plan setting process is further provided, and in the continuous setting process, the temporary setting process, the first plan setting process, and the sequential order receiving plan setting process are repeated to set a production plan, and in the correction process, for each product. The upper limit production amount can be corrected.

[0009] Preferably, the products include planned ordered products that are collectively ordered in addition to the ordered ordered products, and the ordered ordered products and the planned ordered products each have a first feature depending on the characteristics of each product. It is possible to set the elements and the second elements separately. In the temporary setting step, the production plans of the sequentially ordered products and the planned ordered products are temporarily set for each element, and the first plan setting step has the first element. Set the production plan for each product and the product with the second factor, and set each production plan,
The method further comprises a third plan setting step of setting a production plan of the product in the fixed period based on each of the production plans, and in the continuous setting step, the temporary setting step, the first plan setting step and the third plan setting. The process is repeated to set the production plan, and the upper limit production amount can be corrected for each product in the correction process.

Further, preferably, the fixed period and the operation period from the fixed period to the predetermined period so that the production amount leveled in the first plan setting step does not exceed the upper limit production amount. Further comprising a replacement step of replacing the production volume of the sequentially ordered products in and, in the continuous setting step,
The production plan is set by repeating the temporary setting process, the first plan setting process, and the replacement process, and the upper limit production amount can be corrected for each product in the correction process.

[0011]

As described above, according to the first aspect of the invention, the product is continuously produced by the production line for each operation period, and the production plan is prepared so as to level the production within the operation period. At that time, the production plan is provisionally set so that the production of a plurality of sequentially ordered products is performed in a predetermined operation period, and the production amount in the fixed period of the operation period that is equal to or more than the predetermined upper limit production amount is changed from the fixed period. A production plan is set by leveling it during the operation period up to a predetermined period, and for the fixed period after the fixed period, the production plan is set through the same procedure as the temporary setting process and the first plan setting process, and continuous. By comparing the production amount in each operating period set by the above with the maximum production amount set for each operating period, the maximum production amount is corrected to optimize the maximum production amount according to the current order status. Quantity is set , The sequential order product ahead of schedule, it is possible to set the optimum upper limit production even in the case of defeat behind.

According to the second aspect of the present invention, the upper limit production amount is set when the difference between the production amount set in the predetermined continuous operation period and the upper limit production amount is not less than the predetermined amount and the operation period is not less than the predetermined number of times. By correcting, the optimum upper limit production amount can be set in accordance with the current order status, and the optimum upper limit production amount can be set even when the ordered products are moved forward or backward.

According to the third aspect of the present invention, the sequentially ordered products can be set by being differentiated into the first element and the second element according to the characteristics of each product, and the production plan of the sequentially ordered products can be provisionally set for each element. Set the production amount for the product having the first element and the product having the second element, set each production plan, and make the production plan for the product in the fixed period based on each production plan. By setting and repeating the temporary setting process, the first plan setting process, and the sequential order receiving plan setting process to set the production plan, and correcting the upper limit production amount for each product, each element in the multi-product mixed line Can be leveled.

According to the invention of claim 4, the products include planned ordered products that are collectively ordered in addition to the sequentially ordered products.
The sequential order product and the planned order product can be set separately for the first element and the second element according to the characteristics of each product, and the production plan of the sequential order product and the planned order product can be provisionally set for each element. Then, the production amount is leveled for the product having the first element and the product having the second element, each production plan is set, and the production plan for the product in the fixed period is set based on each production plan. However, the provisional setting process, the first plan setting process, and the third plan setting process are repeated to set the production plan, and the upper limit production amount can be corrected for each product. The planned production quantity of the ordered products can be used for leveling, and in particular, the rapid production can be performed in consideration of the production capacity so as to satisfy the production requirements of the sequentially ordered products.

According to the fifth aspect of the invention, the fixed period and the operation from the fixed period to the predetermined period are performed so that the production amount leveled in the first plan setting process does not exceed the upper limit production amount. By changing the production volume of the sequentially ordered products in the period and setting the production plan by repeating the temporary setting process, the first plan setting process and the replacement process, and correcting the upper limit production amount for each product, the current order The optimum upper limit production amount can be set according to the situation, and the optimum upper limit production amount can be set even when the ordered products are moved forward or backward.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The embodiments described below are merely examples of means for realizing the present invention, and the present invention can be applied to modifications or variations of the following embodiments without departing from the spirit of the present invention. . [Overall Configuration] FIG. 1 is a diagram showing an example of the configuration of a computer network for executing the make-to-order production planning method of the present embodiment.

In FIG. 1, when a dealer D at a store or sales office receives an order for a new car from a customer, the order is sequentially registered in real time online in the order file AF of the ordered product A via a network or the like. .

On the other hand, an order for a planned order-received product B to be collectively received domestically and internationally, which is expected based on the past sales record accumulated by the automobile manufacturer, the order forecast of a new vehicle type, etc. (for example, an order is received every month). Overseas products) are registered in the order file BF.

In the production plan creating section 1, the order data registered in the above-mentioned order-accepted product order file AF, the order data registered in the planned order-accepted product order file BF, and the part supply registered in the part inventory file PF. The status data and the product inventory data registered in the product inventory file SF are fetched to sequentially receive the ordered product A and the planned ordered product B.
A production plan is created for each and registered in the production plan file MF.

The production plan registered in the production plan file MF is sent to the production department 2, and parts required for production are ordered from the parts maker 3 according to the production plan.

The computer network of this embodiment uses the above-mentioned order data, parts inventory data, and product inventory data to set the operating days and hours of production equipment, and work schedules (for example, one day is divided into day and night). The production plan for each product is created by leveling the production amount for each product within a predetermined operating period of (shift) within a range not exceeding the upper limit production amount.

Although not shown, automobiles are produced on the basis of a so-called multi-product mixed production line so that a variety of automobiles can be produced appropriately. Is provided. In a production line, a vehicle body on which structural components have been assembled is mounted on a conveyor or other transportation means and transported at a slow speed. Powertrain components such as an engine, a 4WD device, and a differential mechanism, and a brake are delivered to the vehicle body. A plurality of work stations are provided along the line so that chassis parts such as hydraulic pipes and ABS (anti-lock brake system) and accessories such as aero parts can be efficiently assembled. As a result, for example, the differential mechanism and the 4WD device are assembled at the power train component assembly work station, and the brake hydraulic pipe and the AB
S is assembled at the chassis parts assembly work station,
Aero parts are assembled at the equipment assembly work station.

In the computer network of this embodiment, a production plan is created so that the work load of the workers at each of these assembling work stations can be leveled. [Leveling process] Next, the leveling process by the production plan creating unit will be described.

2 and 3 are views for explaining the leveling process by the production plan creation unit 1 of the present embodiment, and in the following, the operation required from the assembly of automobile parts to the vehicle body to the completion of inspection in the automobile production line. 4 periods (N ~
However, the present invention is not limited to this example, and it goes without saying that the operating period can be set in units of operating days and operating hours. It can also be applied to the assembly line of the vehicle body itself. Further, as will be described later, it is possible to change based on sequential order product order data, planned order product order data, parts inventory data, and product inventory data.

Further, the automobile as the product of the present embodiment includes the planned ordered product B to be collectively ordered in addition to the ordered ordered product A as described above, and also includes the ordered ordered product A and the planned ordered product B. Each product (or model or grade)
Depending on the characteristics of A and B, the first element (for example, whether ABS is installed) and the second element (whether 4WD is installed), or a plurality of other elements (presence or absence of aero parts specifications, engine or transmission type, etc.) ), The production plan of the product can be set for each element. In addition to the functions such as ABS and 4WD, the above elements can be classified based on the body color and the like corresponding to the painting line in the painting factory for painting the body of the automobile, which is a product.

In the production plan creating section 1, as shown in FIG. 2A, the production quantity M of the serially ordered product A within the operation period is illustrated.
At the present time, N shifts and 4 as ABS as ordered product A
Product A1 with both WD and aero parts not equipped with M is M
A1 (unit), 4WD with ABS is not equipped with 4WD without aero parts MA2 (unit), 4W with ABS installed
D3 non-installed and aero parts specification product A3 is MA3
(Unit), product A4 without ABS and 4WD and without aero parts is MA4 (Unit), product A5 with ABS and 4WD is not installed, and A5 with Aero parts specifications is MA5 (Unit)
We have received orders for a total of MANs (units). Also, for N + 1 shift, N + 2 shift, and N + 3 shift, one or more of these products A1, A2, A3, A4, A5, respectively,
Total MAN + 1 (Unit), Total MAN + 2 (Unit), Total MAN +
We have received orders for 3 units.

On the other hand, as shown in FIG. 2 (b) as an example of the production amount M of the planned order product B within the operation period, at this time, both the ABS and the 4WD are installed as the planned order product B in the N shift. Product B1 without parts (Both ABS and 4WD are installed, the same as product A1 in that aero parts are not installed) is MB1 (unit), and product B2 with both ABS and 4WD is not installed and aero parts is not installed ( (Same as product A4 in that ABS and 4WD are not installed and aero parts are not installed)
Has received an order for MB2 (unit). In addition, the products that are shipped to special regions such as extremely cold regions, and the special products B0 that are shipped to regions with low shipping frequency and low shipping frequency are produced with a constant production amount MB0 (unit) for every shift. It has been planned to be ordered. In this way, these products B1 and B are also subjected to N + 1 shift, N + 2 shift, and N + 3 shift, respectively.
At least one of 2 and B0 is MBN + 1 (unit),
Total MBN + 2 (units) Total MBN + 3 (units) (Corresponding to the collective order receiving plan setting step described in the claims) The special order product B0 of the planned order receiving products B needs to be always produced systematically, and therefore cannot be leveled. Therefore, the production amount MB0 (unit) of the product B0 is excluded in the leveling process for each element described below. <Leveling for each element including sequential ordered product A and planned ordered product B> Leveled sequential ordered products A1, A2, A3, A4, A5 and planned ordered products other than the excluded product B0 B1 and B2 are classified for each shift so that the production amount for each element can be understood. (Corresponding to the provisional setting step described in the claims) FIG. 3 is a diagram for explaining the leveling process for each element including the sequentially ordered product A and the planned ordered product B.

As shown in FIG. 3 (a), the production volume of ABS-equipped vehicles is as follows: ABS-equipped products A1 and A
A value obtained by totaling the numbers of 2, A3, and B1 (MA1 + MA2
+ MA3 + MB1) (unit). Similarly N + 1, N +
Similar processing is performed in each of the shifts of 2 and N + 3. By such processing, the upper limit production amount of the ABS mounting and assembling work is mab1. In the case of FIG. 3A, the production amount in the N shift and the N + 2 shift exceeds the upper limit production amount mab1, but N + 1. Shift and N
The production amount in the +3 shift is lower than the upper limit production amount mab1.

As shown in FIG. 3 (b), the production amount of the 4WD-equipped vehicle is 4WD-equipped products A1 and B in the N shift.
The total number of units is 1 (MB1 + MA1). Similarly, similar processing is performed in each shift of N + 1, N + 2, and N + 3. By such processing,
The upper limit production amount of the 4WD mounting and assembling work is mab2. In the case of FIG. 3B, the production amount in the N shift is substantially equal to the upper limit production amount mab2, and the production amount in the N + 1 shift is the upper limit. The production amount exceeds mab2. The production amount in the N + 2 shift and the N + 3 shift is less than the upper limit production amount mab2.

As shown in FIG. 3 (c), the production amount of the aeroparts specification vehicle is a value (MA3 + MA) which is the total number of the aeroparts specification products A3 and A5 in the N shift.
5). Similarly, similar processing is performed in each shift of N + 1, N + 2, and N + 3. With such a process, the upper limit production amount of the assembly work of the aero parts is mab3. In the case of FIG. 3C, the production amount in the N + 1 shift and the N + 2 shift exceeds the upper limit production amount mab3. , N shifts and N + 3 shifts are below the upper limit production amount mab3.

The upper limit production amount is set according to the work load of the work station to which each element is assembled. For example,
A case where the upper limit production amount is set on the basis of the work load of the chassis part assembling work station for assembling the ABS will be described as an example. For example, 100 cars are produced on the production line in one shift, and the work load is If it is set as the ABS work condition that three or more vehicles are not continuously mounted with ABS for the vehicles conveyed on the line in order to prevent the assembly operator from having trouble due to excessive number, two consecutive vehicles are installed. Then, after ABS is installed, one is A
Since vehicles without BS are transported, the upper limit of production will be 33 units. The upper limit production volume of 4WD and Aeroverts is similarly set. It should be noted that the upper limit production amount may be set based on the number of the component parts indicated inside, the number of the actually delivered products, and the like.

Next, in order to confirm the N shift, a comparison is made regarding the relationship between each element and each upper limit production amount. According to FIG. 3 (a), the production amount of the ABS-equipped vehicle is larger than the upper limit production amount mab1, and according to FIG. 3 (b), 4W.
The production amount of the D-equipped vehicle is substantially equal to the upper limit production amount mab2, and according to FIG. 3C, the production amount of the aero parts specification vehicle is lower than the upper limit production amount mab3. The procedure of the leveling process in this case is as follows. (1) The following (3) among N-shift ABS equipped vehicles
For the reason (4), a vehicle equipped with ABS in consideration of the leveling of N + 1, N + 2, N + 3 shifts in the production of all or a part of the product of a vehicle not equipped with 4WD and not having aero parts, that is, product A2. Is distributed to at least one of N + 1 and N + 3 shifts in which the total of the above does not exceed the upper limit production amount mab1, and the production amount of the ABS-equipped vehicle in the N shift is adjusted to be equal to or less than the upper limit production amount. (2) The upper limit of the production volume of N-shift ABS equipped vehicles is m
Since it exceeds ab1, ABS-equipped vehicles scheduled to be produced in N + 1, N + 2, and N + 3 shifts will not be set for N-shift production. (3) The production volume of NWD 4WD equipped vehicles is the upper limit production volume m
The same as ab2 (including the case where it is slightly lower than the upper limit production amount mab2) and equipped with 4WD, that is, the production of the products A1 and B1 is not changed to another shift. (4) N shift aero parts specification vehicles have a maximum production capacity of ma
Since it is below b3, it will not be set for production in other shifts. (5) Among the aero parts specification vehicles scheduled to be produced with N + 1, N + 2, N + 3 shifts, the product of the vehicle without ABS and the vehicle without 4WD, that is, the product A5 is N-shifted due to the reasons (2) and (3) above. Change to production. At this time, N + 1, N
In the aeroparts specification vehicle scheduled to be produced with +2 and N + 3 shifts, the degree to which the upper limit production amount mab3 for N + 1 shifts is exceeded is greater than N + 2, so the amount of change to N shifts is either N + 1 shifts or N + 2 shifts. The aero parts specification vehicles that are planned to be produced by N + 1, N + 2, and N + 3 shifts are set to be large, and the change processing is performed so that the production amount at each shift is equal to or less than the upper limit production amount mab3.

Despite the leveling process such as (1) to (5), when the production amount of N shifts in each element exceeds the upper limit production amount, that is, AB in N shifts
When the total production amount of the S-equipped vehicles exceeds the upper limit production amount mab1, the following processing is further performed. (6) Among N-shift ABS-equipped vehicles, products that have elements other than ABS that originally did not exceed the upper limit production volume of N-shift (4WD-equipped vehicles and aeroparts specification vehicles), that is, N + 1 production of products A1, A3, B1
Change to N + 2 and N + 3 shift production.

In this case, for each element, a vehicle equipped with 4WD,
You may prioritize the aero parts specification vehicles in order and shift from the production of N shift products (product A1) having high priority elements to the production of N + 1, N + 2, N + 3 shifts, or N + 1. , N + 2, N + 3 shifts are prioritized from N + 1, N + 2, N + 3 shift products with the factor that the ratio of the order quantity to the production capacity (the sum of the upper limit production amount of each shift) is small from the order situation You may move to.

Further, the planned ordered product B is successively received as the ordered product A.
The production of N + 1, N + 2, and N + 3 shifts may be shifted to a higher priority, and in the case of FIG. 3, the product B1 of N shift is shifted to the production of N + 1, N + 2, and N + 3 shifts.

Even if the production amount of each element of N + 1, N + 2, and N + 3 shifts exceeds the upper limit production amount by the equalization processing such as (1) to (6), the equalization for these shifts is performed when the N shift is confirmed. The processing is not performed, and the leveling processing as in (1) to (6) is performed when each shift is subsequently determined. (Corresponding to the first plan setting step, the second plan setting step, and the third plan setting step described in the claims) Further, as shown in FIG. 4, after the N shift is fixed as the fixed shift, the next shift is N + 1 shift. When confirming
By the same procedure, the production plan is set by allocating the production amount for each element with N + 1 shift to N + 4 shift as a new operation period (continuous setting step).

Since the N shift (old N + 1 shift) and thereafter shown in FIG. 4 may include the production amount distributed from the old N shift and the newly received production amount MAX, these are not included. Leveling is performed with consideration of.

As described above, after N + 1 shifts after N shifts are confirmed, it is possible to perform leveling in accordance with the production volume ordered in real time.

As an effect of the above-mentioned leveling, the order-to-order production A
In the production, the leveling of the delivered amount of each of the above-mentioned element parts and the production amount of the product can be achieved at the same time, and the production without the parts inventory becomes possible.

Further, the production amount of the planned ordered product B can be used for leveling with respect to the increase / decrease of orders in the fixed shift (N shift), and in particular, the production capacity can be increased so as to satisfy the production request of the sequentially ordered product A. Considering this, prompt production is possible.

Further, in consideration of the upper limit production amount of each element (production capacity, that is, the work load on the production line, or the delivered amount of each element part), the order-made production is performed so as to satisfy the production requirement and the production capacity of each element. Can be leveled.

In the present embodiment, the upper limit production amount of each element is set as a preset amount, but when the N shift is confirmed, all orders of the sequential order product A and the planned order product B from N shift to N + 3 shift are received. The amount may be averaged, and the same leveling process may be performed using the average amount as the upper limit production amount. in this case,
The averaging process may be not only the period from the N shift to the N + 3 shift, but also the moving average process or the smoothing process with respect to the total amount of orders in the period before and after the period.

In the present embodiment, when the N shift is confirmed, the ordered order product A from the N shift to the N + 3 shift, the planned ordered product B, and the total order quantity are leveled, but the order fluctuation of the successive order product A is small. May be leveled only with respect to the total order quantity of the sequentially ordered product A. <Prohibition condition of leveling> In the leveling procedure, particularly in leveling procedure (3), when the production amount of the product having each element in N shift is substantially equal to the upper limit quantity, the leveling of the element is prohibited. However, as shown in FIG. 5, the production amount of the product A in the fixed shift (N shift) or the total production amount of the products A and B is the upper limit production amount mab1 for each element.
(Mab2 and mab3 are not shown), if they are substantially the same, the leveling is prohibited according to the order status of the products A and B near the fixed shift (N + 1 shift or N + 1 shift and N + 2 shift). Good (Prohibition setting process).

Specifically, as shown in FIG. 5, products A and B are
As for the order acceptance status, the total production amount of each shift in a predetermined operation period (N + 1 shift and N + 2 shift) in the vicinity of the fixed shift (N shift) is equal to or less than a predetermined first amount maby which is equal to or less than the upper limit production amount (to substantially zero). You can set it)
Since there are too few orders near the fixed shift and the leveling affects the production plan in the subsequent shifts, leveling of this element is prohibited. In this case, when the upper limit production amount is obtained by the moving average process as described above, the influence on other shifts can be reduced by prohibiting the leveling because the influence on shifts before and after is particularly large. Also,
It may be prohibited if the total value is less than or equal to the predetermined second amount, based on the total value of the production amounts in the predetermined operation period (N + 1 shift and N + 2 shift).

Further, as shown in FIG. 5, the definite shift (N
Shift) near a predetermined operating period (N + 1 shift and N
+2 shifts) If the total production amount of each shift is less than or equal to the upper limit production amount and is equal to or greater than the predetermined third amount mabx, the order has been placed in a state close to the substantially upper limit production amount. Prohibits leveling because they do not own.

The leveling prohibition can be appropriately performed for any element, all elements, or a combination of arbitrary elements.

According to the above-described embodiment, in addition to the above-described leveling effect, it is possible to perform prompt production in consideration of the production capacity so as to satisfy the production requirement of the sequentially ordered product A. <Correction of the upper limit production amount in leveling> When the above leveling procedure is continuously executed for the operation period after the N + 1 shift, the production amount and the upper limit in the fixed shift set for each element in each operation period. The upper limit production amount is corrected by comparing it with the production amount (correction step).

More specifically, first, the above-mentioned leveling procedure is continuously executed after N + 1 shifts after the fixed shift (N shift), whereby the production amount of each element is advanced to the fixed shift by the leveling. As a result, the production volume after the fixed shift is reduced. Next, the difference between the total production amount of the products A and B and the upper limit production amount mab1 (the same applies to mab2 and mab3) in the definite shift equalized for each element thus generated is obtained. As a result, when the upper limit production amount is larger than the predetermined amount and continues for a predetermined number of times (a predetermined number of shifts, for example, 5 consecutive shifts), or the upper limit production amount m.
If the condition that ab1 is larger than the predetermined amount by more than a predetermined amount has been present more than a predetermined number of times within a long period such as 1 to 3 weeks or one month,
The upper limit production amount mab1 is corrected downward by a preset amount.

The production amount after the fixed shift is increased by the leveling, and the total production amount of the products A and B and the upper limit production amount mab1 (mab1) in the fixed shift leveled for each element.
(2, mab3 also), as a result, when the upper limit production amount mab1 is smaller than the upper limit production amount mab 1 or more times more than a predetermined number of times (predetermined shift number), or the upper limit production amount m
If the state in which ab1 is smaller than the predetermined amount by more than the predetermined amount exists for a predetermined number of times within a long period of 1 to 3 weeks or one month, the upper limit production amount mab1 may be corrected upward.

At the time of this correction, it is necessary to correct the number of deliveries and the number of internal indicators of the elements to be corrected at the same time, and to take a measure for the work load on the production line.

Further, the upper limit production amount can be independently corrected for each element, and can be executed for all of each element, or any one or a combination of arbitrary elements.

According to the above embodiment, in addition to the leveling effect, the optimum upper limit production amount can be set according to the current order status, and is also suitable when the ordered product A is moved forward or backward. You can set the maximum production capacity. <Correction of number of shifts during operation period> During the above operation period, at least 1 of product order status, parts supply status, product inventory
Correction based on the above (correction step).

More specifically, as shown in FIG. 6, in the order quantity of each element of the product during the operation period from N shift to N + 3 shift, the order quantity of a specific element or the order quantity of all elements during the operation period is Average order volume is near the upper limit of production (amount within ± specified amount of upper limit of production)
If the condition continues for more than a predetermined number of times (predetermined number of shifts), or if this average order quantity is near the upper limit production quantity, it is predetermined within a long period such as 1 to 3 weeks or 1 month. When it exists more than once, the operating period (N shift to N + 1 shift) is shortened to, for example, 3 shifts from N shift to N + 2. As a result, if the operation period is set to be long, products that exceed the upper limit production amount when the N shift is confirmed are likely to be delayed in the latter half of the operation period, which causes a delay in order-to-order production. Therefore, it is possible to correct the operation period so as to reduce the amount of being pushed backward, and it is possible to newly level the amount that fluctuates due to orders in the next operation period. After correcting the operating period from N shifts to 3 shifts of N + 2 shifts, if the frequency that the average order quantity approaches the upper limit production amount decreases, the operating period is changed from the original N shifts to 4 shifts of N + 3 shifts. Perform the returning process.

Further, the supply (inventory) amount of parts can be increased or decreased in a short period of time according to the capacity of the parts factory for providing element parts such as the ABS unit and the aero parts unit to the production line and the work load on the production line. If there is a response to the work load on the production line in a short period of time, the operation period of the element part is corrected so as to be shorter than the operation periods of other elements. As a result, it is possible to suppress an increase in the number of products that fall behind in the latter half of the operation period when the N shift is confirmed.

If the product inventory increases beyond a predetermined amount due to some reason such as an increase in cancellation of ordered products,
Correction is made to extend the operation period, and if the product inventory decreases, the operation period is corrected to the normal period. As a result, it is possible to reduce the influence of inventory increase on the overall production plan.

According to the above-described embodiment, in addition to the effect of the leveling, the operation period for leveling can be set according to the order receiving status of the product, the supply status of parts, the stock of the product, etc. relating to the make-to-order manufacturing. The production can be promptly performed in consideration of the production capacity so as to satisfy the production requirement of the sequentially ordered product A.

In addition, the order status of products, the supply status of parts,
It is possible to optimize the production amount of each element of the product according to the stock of the product. Incidentally, by simultaneously correcting the number of shifts during such an operation period and correcting the upper limit production amount in the above-mentioned leveling, it is possible to further respond to the order status. [Overall Processing] FIGS. 7 and 8 are flowcharts showing the leveling procedure of the present embodiment.

In FIG. 7, in step S1, order data is fetched from each order file of the sequentially ordered product and the planned ordered product, part inventory data from the parts inventory file, and product inventory data from the product inventory file.

In step S3, step S2 described later is executed.
The production quantities of the sequentially ordered product and the planned ordered product for each operation period (N shift to N + k shift) set in 9 are calculated.

In step S5, among the planned ordered products,
Exclude leveling inseparables.

In step S7, the production amount of the sequentially ordered product or the total production amount of the sequentially ordered product and the planned ordered product is provisionally set for each element.

In step S9, it is determined whether there is an element for which the leveling prohibition condition is satisfied, and if there is an element for which the prohibition condition is satisfied (YES in step S9), step S11.
In step S13, the leveling process is executed after the corresponding element is excluded.

In step S15, if the definite shift is decided by the leveling process in step S13 (YES in step S15), it is determined in step S17 of FIG. 7 whether the correction condition for the upper limit production amount is satisfied, and the definite shift is performed. Is not determined (NO in step S15), the process returns to step S1.

In FIG. 8, if the correction condition for the upper limit production amount is satisfied in step S17 (YES in step S17).
S), when the number of shifts set in advance is determined in step S19 (YES in step S19), step S19
At 21, the upper limit production is corrected.

In step S23, a production plan for sequentially ordered products or a combined production plan for sequentially ordered products and planned ordered products is set based on the confirmed shift.

In step S25, the production plan set in step S23 is instructed to the production department, and parts are ordered from the parts maker based on the parts inventory data.

In step S27, the operating period is corrected based on at least one of the product order status, the component supply status, and the product inventory.

In step S29, the operating period is set to the number of shifts corrected in step S27.

A computer program corresponding to the leveling process (including the flowcharts of FIGS. 7 and 8) executed by the network computer and a storage medium storing the computer program are supplied to the computer. Then, the computer may read the program code stored in the storage medium and execute the processing of the above-described embodiment.

[Brief description of drawings]

FIG. 1 is a diagram exemplifying a configuration of a computer network that executes a make-to-order manufacturing plan creation method of the present embodiment.

FIG. 2 is a diagram illustrating a leveling process by a production plan creating unit 1 according to the present embodiment.

FIG. 3 is a diagram illustrating a leveling process performed by the production plan creation unit 1 according to the present embodiment.

FIG. 4 is a diagram illustrating a leveling process performed by the production plan creation unit 1 according to the present embodiment.

FIG. 5 is a diagram illustrating a leveling prohibition condition in the leveling process of the present embodiment.

FIG. 6 is a diagram illustrating a correction condition of an operation period in the leveling process of the present embodiment.

FIG. 7 is a flowchart showing a leveling procedure of the present embodiment.

FIG. 8 is a flowchart showing a leveling procedure of this embodiment.

[Explanation of symbols] 1 Production planning department 2 production departments 3 parts manufacturers AF sequential order product order file BF plan order product order file PF parts inventory file SF product inventory file MF production planning file

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshiki Akane             3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda             Within the corporation (72) Inventor Atsushi Ishii             3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda             Within the corporation (72) Inventor Masako Nakajima             3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda             Within the corporation F-term (reference) 3C100 AA03 AA08 BB02 BB03 BB04                       BB39 EE02

Claims (5)

[Claims] 1. A method of continuously producing a product on a production line for each operation period and creating a production plan so as to equalize the production within the operation period, wherein the product is a sequentially ordered product And a provisional setting step of temporarily setting a production plan so that the production of a plurality of the sequentially ordered products is performed in a predetermined operation period, and a production amount in a fixed period that is equal to or more than a predetermined upper limit production amount in the operation period. A first plan setting step for setting a production plan by leveling the operation schedule from the fixed period to a predetermined period after, and the temporary setting step and the first plan setting step for the fixed period after the fixed period. Comparing the continuous setting process that sets the production plan through the same procedure as above, the production amount in each operating period set in the continuous setting process, and the upper limit production amount set for each operating period MTO planning method characterized by comprising a correction step of correcting the upper limit production by Rukoto. 2. In the correction step, when the difference between the production amount set in a predetermined continuous operation period and the upper limit production amount is a predetermined amount or more and the operation period is a predetermined number of times or more, the upper limit production amount is set. The make-to-order manufacturing plan creation method according to claim 1, wherein the method is corrected. 3. The sequentially ordered product can be set by being differentiated into a first element and a second element according to the characteristics of each product,
In the temporary setting step, the production plan of the sequentially ordered products is temporarily set for each element, and in the first plan setting step, the production amount is leveled with respect to the product having the first element and the product having the second element. The method further comprises a sequential order receiving plan setting step of setting each production plan and setting a production plan of the product in the fixed period based on each of the production plans, wherein in the continuous setting step, the temporary setting step, the first setting step The method of creating a made-to-order production plan according to claim 1, wherein a production plan is set by repeating a plan setting process and a sequential order receiving plan setting process, and the upper limit production amount can be corrected for each product in the correction process. . 4. The planned products, which are collectively ordered, are included in the products in addition to the serially ordered products, and the serially ordered products and the planned ordered products are each classified into a first product by a characteristic of each product.
It is possible to set the element and the second element separately. In the temporary setting step, the production plan of the sequentially ordered product and the planned ordered product is temporarily set for each element, and the first plan setting step has the first element. A third plan setting step of leveling the production amount for the product and the product having the second element, setting each production plan, and setting the production plan for the product in the fixed period based on each production plan. In the continuous setting step, the production plan is set by repeating the temporary setting step, the first plan setting step and the third plan setting step, and the upper limit production amount is set for each product in the correction step. The method for creating a make-to-order manufacturing plan according to claim 1, wherein the method can be corrected. 5. The production amount leveled in the first plan setting step is sequentially performed in the fixed period and the operation period from the fixed period to a predetermined period so as not to exceed the upper limit production amount. The manufacturing method further comprises a replacement step for replacing the production volume of the ordered product, wherein the continuous setting step sets the production plan by repeating the temporary setting step, the first plan setting step, and the replacement step, and the correction step includes setting for each product. On the other hand, the method of creating a made-to-order production plan according to claim 1, wherein the upper limit production amount can be corrected.