JP2015225364A - Manufacturing method and manufacturing management program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method and manufacturing management program, capable of suppressing a manufacturing line stop.SOLUTION: A manufacturing method comprises the steps of: determining by a determination part whether or not an assistant is called on the basis of a work start position to a product conveyed by conveying means and a work time of the product; specifying a work requiring a period of time longer than the excess of the work time to a workable time determined from the work start position when determined that the assistant is called; and presenting the specified work to the assistant by presentation means.

Description

  This case relates to a manufacturing method and a manufacturing management program.

  In a production line for assembling products, for example, unfinished products are conveyed by a conveying means such as a conveyor, and a work range is assigned to the worker. When a delay occurs in the work, the delay can be recovered by calling a supporter. Therefore, it is considered to provide a determination point for determining whether or not to call a supporter before the stop line for determining the stop of the production line (for example, see Patent Document 1).

JP-A-7-31615

  However, if a product that requires more work time than the average during the mixed flow production is to be manufactured regularly, support requests will continue even with a slight delay in work, and support from the supporter will not be in time. In this case, the product may exceed the stop line, and the production line may stop.

  In one aspect, an object of the present invention is to provide a manufacturing method and a manufacturing management program capable of suppressing a stop of a manufacturing line.

  In one aspect, a manufacturing method determines whether a supporter is called based on the work start position with respect to the product conveyed by the conveyance means, and the work time of the product, and calls the supporter. When it is determined that the work that requires more time than the work time exceeding the work available time obtained from the work start position is specified by the specifying unit, and the specified work is presented to the supporter by the presentation unit To do.

  In one aspect, the manufacturing management program calls the supporter, a process for determining whether to call a supporter based on the work start position for the product transported by the transport means and the work time of the product. When it is determined that, the process of specifying work that requires more time than the excess of the work time with respect to the work possible time obtained from the work start position, and the process of presenting the specified work to the supporter Let the computer run.

  Stopping of the production line can be suppressed.

It is the schematic for demonstrating an example of a manufacturing line. (A) is a figure which illustrates about a synchronous trolley | bogie and a sub assembly, (b) is a pile table which represented the operation | work which the worker of 2 processes-4 processes performed on the time axis. (A) is a figure which illustrates tact time, (b) is a figure which illustrates about the zone of work. It is a block diagram which illustrates the composition of a manufacture management device. It is a figure for demonstrating the detection of the completion of work in each process. It is a figure for demonstrating the detection of the work start in each process. (A) is an example of a flowchart for determining whether or not a delay occurs in the work, and (b) is a diagram illustrating the cycle time CTb. It is an example of the flowchart for demonstrating the work specific of the support object requested | required of a supporter. It is an example of a whole flowchart. (A) is a figure which illustrates cycle time CTb and standard work time, (b) is a figure showing an example of the relationship between work possible time t0 and cycle time CTb. (A) is a figure which illustrates cycle time CTb and standard work time, (b) is a figure showing an example of the relationship between work possible time t0 and cycle time CTb. (A) is a figure which illustrates cycle time CTb and standard work time, (b) is a figure showing an example of the relationship between work possible time t0 and cycle time CTb. It is a block diagram for demonstrating the hardware constitutions of a manufacturing management apparatus.

  Prior to the description of the embodiments, the outline of the production line will be described. FIG. 1 is a schematic diagram for explaining an example of a production line. As illustrated in FIG. 1, unfinished products 12 are placed on the conveyor line 11 at a predetermined interval (pitch). Each product 12 is not necessarily the same product, and different types of products may be mixed. While the product 12 is being conveyed by the conveyor line 11, the worker performs a predetermined operation on the product 12. One pitch of the arrangement of the products 12 is determined so as to correspond to a tact time necessary for performing each work. The tact time is a process work time determined in order to achieve an equal timing of each process. For example, the tact time is an average value of standard work time that must be performed on each product 12.

  One worker is assigned a zone corresponding to two pitches. Normally, each worker starts work at the head of the latter stage of the two pitches, moves with the product 12, and completes the work while the product 12 moves one pitch. The worker repeats this flow. A call determination point is set for the latter stage pitch. If the work is completed before the call determination point, it can be determined that the work of the worker is progressing. If the work is completed past the call point, it can be determined that the work of the worker is delayed. The work delay is caused by an abnormality related to the quality of the product 12, a delay in supplying parts, an excessive work time, and the like. If the work is delayed, the caller 13 can call the supporter. As an example, the last position of the latter pitch is defined as a fixed position stop line. If the supporter does not arrive by this fixed position stop line, the production line will stop.

  Fig.2 (a) is a figure which illustrates about a synchronous trolley | bogie and a sub assembly. The sub table is arranged in two pitches assigned to each worker. A synchronous cart is assigned to each worker. Of the two pitches assigned to each worker, the zone with the preceding pitch is referred to as the driving zone, and the zone with the subsequent pitch is referred to as the working zone. Each worker works on the product mainly in the work zone.

  The synchronous cart 14 is a cart for working the product, stocks small parts such as screws, jigs and tools, and is detachable from the tray 15 on which the product is placed. Each worker attaches the synchronous carriage 14 to the tray 15 that has entered the work zone, starts work on the product in the tray 15, and completes the work while the tray 15 is transported through the work zone.

  In the example of FIG. 2A, the main body 16 of the product and the component 1 are placed on the tray 15 that has entered the two-step work zone. The worker in the two steps performs work for the main body 16 and also creates the part 2. The worker performs work other than the main body 16 at the sub-assembly 17. Therefore, the worker in the two steps performs the operation for creating the component 2 in the sub assembly 17 after performing the operation on the main body 16 in the tray 15, and completes the operation by placing the completed component 2 on the tray 15. . The operator of the three steps performs the work of creating the part 3 in the sub assembly 17 after performing the work of incorporating the part 1 into the main body 16 in the tray 15, and placing the completed part 3 on the tray 15. Complete. The worker of the four steps performs the work of creating the part 4 in the sub-assembly 17 after the work of incorporating the part 2 into the main body 16 in the tray 15, and the work is performed by placing the completed part 4 on the tray 15. Complete.

  FIG.2 (b) is the pile table which represented the operation | work which the worker of 2 processes-4 processes performed on the time axis. For example, the operation of assembling the part 2 created by the sub assembly machine 17 of the two steps is included in the main operation of the four steps. When the work by the worker is delayed, the supporter mainly supports the work performed on the sub-assembly 17. Thereby, it becomes possible to recover the delay of each worker.

  Production plan (production sequence table) is the ratio of different products (products with different assembly cycle times) within the unit time according to the delivery time of truck flights (4 flights / day, etc.) corresponding to orders and sales ratio Has been decided to produce in. In general, it is possible to manufacture a product B with a large man-hour in a time obtained by accumulating a time margin by continuously manufacturing a product A having a smaller man-hour than the tact time of the line, and adding the margin time to the tact time. .

  For example, as illustrated in FIG. 3A, it is assumed that the standard work time of the product A is 50 seconds and the standard work time of the product B is 90 seconds. In this case, by setting the production ratio A: B to 3: 1, the weighted average of 60 seconds can be set as the tact time. That is, the tact time can be set to 60 seconds by performing the work for the product A three times and the work for the product B once.

FIG. 3B is a diagram illustrating a zone of work performed in this case.
As illustrated in FIG. 3B, if the tact time of the work zone is set to 60 seconds, the work of the product A is completed in 50 seconds, so that the next product A can be worked in the driving zone. Can start. If this is repeated three times, a margin of 30 seconds can be obtained, and 90 seconds for working the product B can be secured.

  Here, in the manufacture of the product A with a small man-hour, a delay that does not exceed the tact time is accumulated, and the manufacture of the product B with a large man-hour may be started without reaching the estimated margin time. In this case, the delay in manufacturing the product B is detected for the first time when the carriage or the conveyor reaches the “call determination point”. When a delay is detected, a supporter is called to perform support work.

  The supporter also serves as support work for a plurality of processes. For this reason, when the supporter is performing the support work in a certain process, if the support work in another process is instructed, the support work instructed next cannot be performed immediately. As a result, the next instructed support work may not be in time, and the line may stop. In addition, the above situation may occur at intervals of product ratios in a certain unit time. Therefore, in the following embodiments, a manufacturing method and a manufacturing management program that can suppress the stop of the manufacturing line will be described.

  FIG. 4 is a block diagram illustrating the configuration of the manufacturing management apparatus 100. As illustrated in FIG. 4, the manufacturing management apparatus 100 includes a synchronous cart attachment / detachment sensor 10, a position sensor 20, a work time calculation unit 30, a database 40, a determination unit 50, a work identification unit 60, a display device 70, and the like.

  The synchronous cart attachment / detachment sensor 10 is a sensor that detects that the synchronous cart 14 is attached to each tray 15 and that the synchronous cart 14 is removed from each tray 15, and is a micro switch, a conduction switch, or the like. The position sensor 20 is a sensor that detects the position of the tray 15 in the production line, and is a distance sensor, a reflection sensor, or the like. The position sensor 20 can also detect the conveyance status of the tray 15 by detecting the position of the tray 15 in association with the time axis. The work time calculation unit 30 calculates the work available time for the product on each tray 15.

  The database 40 stores production line setting data, tact time data, cycle time data for each process (a pile of standard work hours for each product), product input sequence data, and the like. The determination unit 50 determines whether work is delayed. The work specifying unit 60 specifies the work to be supported that is requested from the supporter. The display device 70 is a device that presents information regarding work delay, and is, for example, a lamp, a display, or the like. The display device 70 notifies the work delay using the lamp and presents the work to be performed by the worker and the supporter. Other presentation means such as voice may be used. Details of the functions of the respective units will be described below.

  FIG. 5 is a diagram for explaining detection of work completion in each process. As illustrated in FIG. 5, the manufacturing management apparatus 100 detects that the synchronous carriage 14 has been removed from the tray 15 and that the tray 15 is being conveyed by the conveyor line 11 in the work zone. Judge that completed. Therefore, the manufacturing management apparatus 100 detects the completion of work in each process based on the detection results of the synchronous cart attachment / detachment sensor 10 and the position sensor 20.

  FIG. 6 is a diagram for explaining detection of work start in each process. As illustrated in FIG. 6, the manufacturing management apparatus 100 determines that the operation has been started when the synchronous carriage 14 is attached to the tray 15. Therefore, the manufacturing management apparatus 100 detects the work start in each process based on the detection result of the synchronous cart attachment / detachment sensor 10. Further, the manufacturing management apparatus 100 detects the position of the tray 15 at the start of work as the work start position based on the detection result of the position sensor 20.

  A distance from the foremost position of the driving zone to the current position of the tray 15 (for example, the center point of the tray 15) is defined as a distance L1. Further, the distance from the current position of the tray 15 to the last position (fixed position stop line) of the work zone is defined as a distance L2. The total distance (distance for two pitches) of the driving zone and the work zone is defined as a distance L. According to this definition, L = L1 + L2.

FIG. 7A is an example of a flowchart for determining whether or not work is delayed. As illustrated in FIG. 7A, the work time calculation unit 30 calculates a work possible time t0 for a product for which work has been started (step S1). Specifically, the work time calculation unit 30 calculates the work available time t0 according to the following equation (1). “V” is the transport speed of the tray 15. The conveyance speed v may be defined by the production line setting data stored in the database 40 or may be calculated based on the detection result of the position sensor 20.
t0 = (L−L1) / v (1)

  Next, the determination unit 50 acquires the cycle time CTb of the target product from the database 40 (step S2). The cycle time CTb is the total time of the standard work time of each work for the target product. FIG. 7B illustrates the cycle time CTb. In the example of FIG. 7B, the cycle time CTb is the total time from the standard work time t1 of the work 1 to the standard work time t4 of the work 4.

  Next, the determination unit 50 determines whether or not there is a delay by comparing the workable time t0 and the cycle time CTb (step S3). Specifically, determination unit 50 determines that a delay occurs if workable time t0 is smaller than cycle time CTb. In the example of FIG. 7B, it is determined that a delay occurs. When it determines with "Yes" by step S3, the display apparatus 70 performs the display which calls a cheerer (step S4). When it determines with "No" by step S3, the display apparatus 70 does not call a cheerer (step S5).

  FIG. 8 is an example of a flowchart for explaining the identification of the work to be supported that is requested from the supporter. As illustrated in FIG. 8, the work identifying unit 60 calculates a support amount Δt0 (step S11). The cheering amount Δt0 is obtained by subtracting the workable time t0 from the cycle time CTb. Next, “1” is substituted into the variable “n” (step S12).

  Next, the work specifying unit 60 calculates a difference Δtn between the standard work time tn of the work n and the support amount Δt0 (step S13). The difference Δtn is obtained by subtracting the support amount Δt0 from the standard work time tn. Next, the work identifying unit 60 determines whether or not the difference Δtn is greater than zero (step S14). When it is determined as “Yes” in Step S14, the work identifying unit 60 determines whether or not the difference Δtn is smaller than the difference Δtn−1 (Step S15). When it is determined as “Yes” in Step S15, the work identifying unit 60 holds the work n as a support work (Step S16).

  Next, the work specifying unit 60 determines whether or not all work has been compared (step S17). Specifically, it is determined whether or not the variable n has reached the maximum value nmax. In the example of FIG. 7B, the maximum value nmax of the variable n is “4”. When it is determined as “No” in Step S17, the work identifying unit 60 adds “1” to the variable n (Step S18), and executes again from Step S12. If “No” is determined in step S14 and step S15, step S19 is executed.

  When it determines with "Yes" at step S17, the display apparatus 70 shows the operation | work which the work specific | specification part 60 hold | maintained at step S16 as a support operation | work. Also, other work is presented as a regular work to a regular worker (step S19). According to this flowchart, a work having a work amount larger than the cheering amount Δt0 and closest to the cheering amount Δt0 is specified as the cheering work.

  FIG. 9 is an example of an overall flowchart showing the above flow. The flowchart of FIG. 9 is a flowchart that is executed while paying attention to each process, and is executed in parallel for each process. As illustrated in FIG. 9, the completion of the operation is detected by detecting that the synchronous carriage 14 is removed from the tray 15 by the synchronous carriage attachment / detachment sensor 10 (step S21).

  Next, in the previous step, the synchronous cart attachment / detachment sensor 10 determines whether or not the synchronous cart 14 has been removed from the tray 15 (step S22). If “Yes” is determined in step S22, in the previous step, the position sensor 20 determines whether or not the tray 15 is being conveyed in the work zone (step S23). If it is determined as “Yes” in step S23, the synchronous cart attachment / detachment sensor 10 determines whether or not the synchronous cart 14 is attached to the tray 15 in its own process (step S24). If it is determined as “No” in any of steps S22 to S24, the process is executed again from step S21.

  If it is determined as “Yes” in step S24, the position sensor 20 detects the current position of the tray 15 to detect the work start position (step S25). Next, the work time calculation unit 30 calculates a work possible time t0 (step S26). Next, the determination unit 50 acquires from the database 40 the cycle time CTb of the product that has been transported to its own process (step S27).

  Next, the determination unit 50 determines whether or not a delay occurs by comparing the workable time t0 and the cycle time CTb (step S28). If "No" is determined in step S28, the process is executed again from step S21. When it determines with "Yes" at step S28, the display apparatus 70 performs the display which calls a cheerer (step S29).

  Next, the work identifying unit 60 calculates a necessary support amount Δt (step S30). Next, the work identifying unit 60 selects a support work from the cycle time CTb (step S31). Next, the work specifying unit 60 compares the standard work time of the support work selected in Step S31 with the support amount Δt (Step S32). Next, the work identifying unit 60 determines whether or not the support amount Δt is smaller than the standard work time (step S33). When it is determined as “Yes” in Step S33, the work specifying unit 60 determines whether or not the standard work time is minimum (Step S34). If “No” is determined in step S33 or step S34, another support operation is selected in step S31, and steps S32 to S34 are executed again.

  When it is determined as “Yes” in Step S34, the display device 70 presents the support work to the supporter (Step S35). Next, the display device 70 presents another table as a regular work to a regular worker (step S36). With the above flow, execution of the flowchart ends.

  Hereinafter, an example of the relationship between the workable time t0 and the cycle time CTb will be described. FIG. 10A is a diagram illustrating the cycle time CTb of the product A and the product B and the standard work time of each work. Since the number ratio of the product A is 75% and the number ratio of the product B is 25%, as an example, one product B is transported after three products A are transported. The tact time is 60 seconds.

  FIG. 10B is a diagram illustrating an example of the relationship between the workable time t0 and the cycle time CTb. As illustrated in FIG. 10B, it is assumed that the work for the first product A is completed in 50 seconds. In this case, for the second product A, the workable time t0 is 70 seconds. Therefore, it is determined that no delay occurs. It is assumed that the work for the second product A is completed in 50 seconds. In this case, for the third product A, the workable time t0 is 80 seconds. Therefore, it is determined that no delay occurs. It is assumed that the work for the third product A is completed in 50 seconds. In this case, for the product B, the workable time t0 is 90 seconds. Therefore, it is determined that no delay occurs. Assume that the work for product B is completed in 90 seconds. In this case, for the next product A, the workable time t0 is 60 seconds. Therefore, it is determined that no delay occurs.

  FIG. 11A is a diagram illustrating the cycle time CTb of the product A and the product B and the standard work time of each work, and is the same as FIG. 10A. FIG. 11B is a diagram illustrating an example of the relationship between the workable time t0 and the cycle time CTb. As illustrated in FIG. 11B, it is assumed that the work for the first product A is completed in 50 seconds. In this case, for the second product A, the workable time t0 is 70 seconds. Therefore, it is determined that no delay occurs. It is assumed that the work for the second product A is completed in 54 seconds (4 seconds delay). In this case, for the third product A, the workable time t0 is 76 seconds. Therefore, it is determined that no delay occurs. Assume that the work for the third product A is completed in 56 seconds (6 seconds delay). In this case, for the product B, the workable time t0 is 80 seconds. Therefore, it is determined that a delay occurs. In this case, the work Bd having a minimum standard work time exceeding 10 seconds obtained by subtracting the work possible time t0 from the cycle time CTb is displayed to the supporter as the support work.

  FIG. 12A illustrates the cycle time CTb of the product A and the product B and the standard work time of each work. FIG. 12B is a diagram illustrating an example of the relationship between the workable time t0 and the cycle time CTb. The example of FIG.12 (b) is an example when simultaneous support is needed by two processes. In one process, the work Bd having a minimum standard work time exceeding 10 seconds obtained by subtracting the work possible time t0 from the cycle time CTb is displayed to the supporter as a support work. In the three steps, the work Bi having a minimum standard work time exceeding 18 seconds obtained by subtracting the work possible time t0 from the cycle time CTb is displayed to the supporter as the support work.

  According to the present embodiment, a supporter can be called at the start of work that is expected to be delayed, and instructions for support work corresponding to the delay can be issued. Thereby, the supporter's time can be secured for a long time. By increasing the supporter's time, even if support work occurs simultaneously in another process after the support work of one process ends, the work in another process can be started and completed by the delay limit. Thereby, the stop of a manufacturing line can be suppressed. From the above, products having a large man-hour difference (less than twice in the case of 2 pitches) can be produced on the same line, and the production efficiency of the entire line is improved.

  In addition, in the said Example, when it was judged that a delay generate | occur | produced, the operation | work of the minimum standard work time exceeding the cheering amount (DELTA) t was specified as a cheering work, but it is not restricted to it. Any work with a standard work time exceeding the support amount Δt may be specified as the support work. Even in this case, since the product does not need to cross the fixed position stop line, the stop of the production line can be suppressed.

(Other examples)
FIG. 13 is a block diagram for explaining the hardware configuration of the manufacturing management apparatus 100. Referring to FIG. 13, manufacturing management apparatus 100 includes CPU 101, RAM 102, storage device 103, interface 104, and the like. Each of these devices is connected by a bus or the like. A CPU (Central Processing Unit) 101 is a central processing unit. The CPU 101 includes one or more cores. A RAM (Random Access Memory) 102 is a volatile memory that temporarily stores programs executed by the CPU 101, data processed by the CPU 101, and the like. The storage device 103 is a nonvolatile storage device. As the storage device 103, for example, a ROM (Read Only Memory), a solid state drive (SSD) such as a flash memory, a hard disk driven by a hard disk drive, or the like can be used. Each part of the manufacturing management apparatus 100 is implement | achieved when CPU101 runs a manufacturing management program. Alternatively, the manufacturing management apparatus 100 may be hardware such as a dedicated circuit.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 10 Synchronous cart attachment / detachment sensor 11 Conveyor line 12 Product 14 Synchronous cart 15 Tray 16 Main body 17 Sub assembly 20 Position sensor 30 Work time calculation part 40 Database 50 Judgment part 60 Work specification part 70 Display apparatus 100 Manufacturing management apparatus

Claims (4)

The determination unit determines whether to call a supporter based on the work start position for the product transported by the transport means and the work time of the product,
When it is determined to call the supporter, the work that requires more time than the work time over the work possible time obtained from the work start position is specified by the specifying unit,
The manufacturing method characterized in that the specified work is presented to a supporter by a presentation means.   The manufacturing method according to claim 1, wherein the presented work is a work that takes more time than an excess of the work time with respect to the workable time and is a minimum time work. The product is conveyed by a tray on the conveying means,
The manufacturing method according to claim 1, wherein the work start position is a position where a work cart for the product is attached to the tray. A process of determining whether or not to call a supporter based on the work start position for the product transported by the transport means and the work time of the product;
When it is determined to call the supporter, a process for identifying a work that requires more time than the work time over the work possible time obtained from the work start position;
A manufacturing management program that causes a computer to execute a process of presenting the identified work to a supporter.

Images