JP4647809B2 - production management system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a production management system, and more particularly to a production management system in a discrete continuous processing process in which processes such as a chemical reaction, deformation, processing, filling, and inspection are continuously processed.
[0002]
[Prior art]
As shown in FIG. 8, the production forms include processes such as a batch type process, a continuous flow process, a discrete type job shop process, a discrete type repetition process, and a discrete type continuous processing process, and each has the following characteristics.
[0003]
The batch type process is suitable for continuous small-volume production, and since it is processed in lot units consisting of a predetermined number throughout the entire process, the quality in the lot is considered to be constant, so it is easy to manage. .
[0004]
The continuous flow process is suitable for continuous mass production, and it is difficult to inspect the quality of each part during processing, but the product is often stored in a certain quantity, and at that time a lot is composed Quality can be confirmed in lot units.
[0005]
Discrete type job shop process is suitable for discrete type small-scale production. In each process, work is performed on a specific work (intermediate product), and each work is identified and the work result is recorded and inspected. It is easy to manage quality.
[0006]
The discrete repetitive process is suitable for discrete mass production, and in many cases, a product for assembling parts that have already been inspected is often completed. In this case, the results of processing in each process can be accurately recorded, and the product quality can be assumed with a high probability from the results of the inspection in parts and the product inspection at the prototype stage. Specific inspection method can be set.
[0007]
The discrete continuous processing process is located between the discrete repetitive process and the continuous flow process. Each separated work is sequentially transferred to the necessary steps by a conveyor, etc., and processed to produce the final product. It is a form. Processing in each process includes many elements such as chemical reaction and deformation, not assembly. In this production mode, it is difficult to identify each workpiece, record what processing has been performed in each process, and confirm the quality of the workpiece other than sampling inspection.
[0008]
Further, in the production mode as described above, a process management method for maintaining quality has been proposed in the past, and as a general process management method, production is performed in each process for each predetermined number of lots. Thus, the production process is managed by using a lot management method for production management. Lot management is a technique for managing the work in each of multiple processes for each lot, and if a defective product is found in the middle process or final process, it is not possible to use a predetermined number of lots as a unit. A non-defective product lot can be identified, and a follow-up survey of defective products can be performed quickly and appropriately. In addition, since the number of defective products can be tracked by lot, when mass production is performed, defective products are sorted by lot, so that all products are not inspected or discarded. Can be treated.
[0009]
In addition, holding various data such as quality data corresponding to each lot facilitates analysis of defective products, and is widely used as an effective means for analyzing the cause of defective products.
[0010]
For example, in the technique described in Japanese Patent Laid-Open No. 2000-29955, the lot number and lot information input corresponding to each process are recorded for each process, and all subsequent processes except the first process are recorded. In each process, a lot information record file that records the lot number of the previous process in association with the lot number of the process, the serial number assigned to each part manufactured in the first process, and the first process A serial information recording file for storing the lot number and the lot number of the last process in association with each other, and the information tracking control means retrieves the lot number in the first process and the lot number in the last process from the serial information recording file. Based on this lot number, sequentially search the lot number of the previous process from the lot information record file. More, it is disclosed that can extract information products that serial number over the entire process. That is, in Japanese Patent Application Laid-Open No. 2000-29955, work information in each process can be extracted from a serial information number, and analysis analysis of defective products can be easily performed.
[0011]
[Problems to be solved by the invention]
However, in the conventional lot management technique, the workpieces separated one by one are sequentially transported to the necessary processes by a conveyor or the like, and a production form in which many processes such as chemical reaction and deformation are performed instead of assembly in each process, That is, it is difficult to perform lot tracking in a production form such as a discrete continuous process. For example, in the production of plastic containers, etc., raw materials are mixed and molded, but it is difficult to handle lots of raw materials and products. Furthermore, in mass production, it is difficult to put an identification mark or the like for identifying a lot on the product itself. Therefore, in order to determine which range of products may be affected when a defect occurs in a certain process, a large amount of margin (for example, per day) is set. There is a problem that there is an increase in sorting and disposal.
[0012]
In addition, since the relationship between the product and each processing data cannot be specified, it is difficult to assure the quality when the 100% inspection is not performed. Furthermore, when a defective product is found by sampling inspection of the product, it is impossible to specify which factor in which process is the cause, and it is difficult to improve the quality. And since the effect of the processing result of a certain process on the next process and the final product cannot be grasped clearly, it is necessary to tighten the processing conditions of each process. It was generated.
[0013]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a production management system that can easily specify a state relating to quality in each process regardless of a production form.
[0014]
[Means for Solving the Problems]
  In order to achieve the above object, the invention described in claim 1 includes a detecting means for detecting an amount of an object entering and exiting each step when forming a processed product from a raw material after passing through a plurality of steps, and the detecting means. Each of the above steps was completed based on the detection result ofAmong the objects, from the predetermined reference point in each processStorage means for calculating a cumulative value of the amount of product and storing the calculation result together with time information;Transit time when a product set in advance as a tracking target has passed a predetermined process, andBased on the characteristic function indicating the process status including at least the processing status in each process and the connection status between the processes, the time information stored in the storage means and the set value of the set productPredeterminedAnd a specifying unit that specifies the passage time of the product in each step other than the step.
[0015]
  According to the first aspect of the present invention, the detecting means detects the amount of an object (for example, a product, a work (intermediate product), a raw material, etc.) that enters and exits each process. Then, the storage means calculates a cumulative value of the amount of objects entering and exiting each process detected by the detection means, and stores the calculation result together with time information. That is, the number of defective products in each step, the production results of non-defective products (production number), and the like are stored together with time information. Note that the cumulative value of the quantity of the product is a cumulative value from a predetermined reference point (for example, at the start of production or at the start of work).The
[0016]
  And in the identification means,The time when a product set in advance as a tracking target passes a predetermined process, andCharacteristics of each processTo numberBased on the time information stored in the storage meansAnd cumulative valueFromOther than the predetermined process of the product preset as the tracking targetThe passage time of the product in the process is specified. That is, since the time for passing through each process (standard time for processing in each process) is determined for each process, if the product passing time in a certain process is set, the setting information and each The time when the product passes through each process can be specified from the standard time of the process. In this way, the passing time of each process of the product can be specified, so if data such as processing conditions in each process is stored together with the time, the processing conditions in each process at that time can be easily confirmed. be able to.
[0017]
Therefore, since it is possible to track the processing conditions in each step of the product without having to directly assign a lot number to the product for each step, it is possible to easily specify the quality-related state in each step regardless of the production form. be able to.
[0018]
According to a second aspect of the present invention, in the first aspect of the invention, the storage unit further stores manufacturing data in each of the plurality of steps together with time information, and the specifying unit includes the product in each step. Based on the passage time, manufacturing data corresponding to the product is further specified.
[0019]
According to the second aspect of the invention, in the first aspect of the invention, the storage unit further stores the manufacturing data in each of the plurality of steps together with time information. That is, since the data of the product including raw materials and workpieces used in each process is stored together with the time information used, the manufacturing data in each process (for example, used for the product) is specified by specifying each process passing time. It is possible to further specify the workpiece data including the processed raw materials and the processing conditions in each process by the specifying means.
[0020]
  Note that the detection means is the amount of the entry / exit, as in the third aspect of the invention.NumberThe amount may be detected, and as the invention according to claim 4,QualityThe amount may be detected.
[0021]
  Also, ContractAs in the invention described in claim 5,The detection means isFurther detection of environmental conditions for each process (for example, measured values for equipment conditions in each process)The storage means further stores the environmental conditions together with the time information, and the specifying means further specifies the environmental conditions in each step of the product set from the environmental conditions stored in the storage means.By doing so, it becomes possible to grasp the relationship between product quality and manufacturing data.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an outline of a production management system according to an embodiment of the present invention.
[0023]
As shown in FIG. 1, the production management system 10 according to the embodiment of the present invention includes a plurality of processes X (i) (i = 1, 2,..., N−1, n). Thus, various processes are performed to produce a product. In addition, the production form of the production process 10 according to the embodiment of the present invention is a discrete continuous process, and various processes performed in each process perform a process including many processes such as chemical changes and deformations. It is assumed that this applies to products that are mass-produced.
[0024]
As shown in FIG. 2, each process is provided with detection means 12 for detecting the amount of objects entering and exiting each process. That is, the detection means detects the number of defective products discharged in each process, such as the number and mass of products and raw materials including workpieces transferred to each process, and the number of products transferred from each process. For example, the detection means 12 detects the number of products input / output and the mass of raw materials for each process.
[0025]
Each process is connected to the control means 14 (see FIG. 1) for managing all processes, and the detection result of the detection means 12 provided in each process is output to the control means 14 and at each process. Processing conditions (for example, conditions that can be set in each process such as temperature, pressure, humidity, etc.) to be performed are output to the control means 14. Further, in each process, product manufacturing data (for example, data on raw materials used in each process) in each process is input and output to the control means 14. In addition, various types of information output to the control unit 14 (detection results of the detection unit, processing conditions, raw material data, and the like) are output to the control unit 14 after time information corresponding to each information is given. The control means 14 corresponds to the specifying means and storage means of the present invention.
[0026]
The control means 14 is composed of a computer having a CPU, ROM, RAM, and peripheral devices (not shown), stores information obtained from each process together with time information, and processes in each process and between each process. A characteristic function indicating the process status such as the connection status (for example, it is possible to calculate based on the detection result of the detection means 12 shown in FIG. 2, that is, the amount and time of an object entering and exiting each process). ing. And production management is performed based on each process passage time and a characteristic function. That is, when a defective product is found in a certain process and the defective product is investigated, in the upstream process or downstream process of the process in which the defective product is found from the production time in the process in which the defective product is discovered by the control means 14. The processing time is calculated, and from the calculated time in each process, the number of productions in each process, processing conditions in each process, data such as raw materials (manufacturing data), etc. can be detected. .
[0027]
It should be noted that environmental conditions such as actually measured values for equipment conditions in each process may be further stored in the control means 14 together with time information, and environmental conditions in each process for defective products may also be detected as manufacturing data.
[0028]
Next, the operation of the production management system 10 configured as described above will be described.
[0029]
In each process, data such as raw materials to be used (manufacturing data) is input in each process with the time to be used, and the input information with the time is output to the control means 14 and stored in the control means 14. Is done. Further, the detection means 12 of each process detects the number of products including the workpieces input / output to / from each process, the mass of the raw material, and the like, and outputs them to the control means 14 together with the time processed in each process. .
[0030]
In a process where the number of defective products cannot be specified, the number of products containing workpieces that stay in the standard condition in the process is registered as the retention setting value in the process characteristic function, and detected at the entrance and exit. By estimating the number of defective products in real time from the number of products to be processed, the estimation result is output to the control means 14. Further, when a lot is configured by collecting a product including a workpiece on a pallet or the like in which a predetermined number is stored, the detection means 12 detects the number of products stored in the pallet and the number of pallets, and the lot number and a predetermined number are detected. The cumulative number of products from the reference point is stored in the control means 14 together with the time. Furthermore, when powder or liquid raw materials are used as raw materials, the mass used in the process is detected, and if there is an integrated value from a predetermined reference point and the raw material lot number, the raw material lot number is the time At the same time, it is stored in the control means 14.
[0031]
As shown in FIG. 3, the number of products input / output and the mass of raw materials for each process are, as shown in FIG. 3, between process A (process A-process B), process A 16 exit A, process B 18 entrance B, process B 18. Are defined by the following equations, respectively.
[0032]
    ExitA = Inlet A + Defect discharge A + Residence value (1)
    Inlet B = Outlet A + Residence value AB (2)
    Outlet B = inlet B + defective discharge B1 + defective discharge B2 + residence value B (3)
  And in the control means 14, based on the information obtained from the detection means 12, and the formulas (1) to (3), production accumulation (production results) in each process from a predetermined reference point (for example, production start) is calculated. Calculated.
[0033]
Therefore, based on these information, the control means 14 sequentially goes to the upstream process based on the time information obtained from each process and the characteristic function (including the transfer time between processes) required for performing the process in each process. You can simulate the movement of objects. In this way, a product has passed a certain process by setting the lot of each process at each time toward the upstream process based on the production results with time of the subsequent process (final process) and the characteristic function of each process. Lot tracking can be simulated from the time, and the state relating to quality in each process (for example, raw material data, production conditions of each process, etc.) can be specified. In addition, even when there is a stop of the production process by storing the stop time for the stop of the production process (including abnormal stop in each process) and considering the stop time, the production time of the product between each process Can be supported.
[0034]
For example, a case will be described as an example where the total number of processes is 5, and the total production at each time for each predetermined time in each process is produced as shown in FIG. In FIG. 4, the number of production in each process is the number detected at the exit of each process for the sake of simplicity, there is no defective product, and the product lot in the final process consists of 400 non-defective products. Will be described. That is, as described above, information (such as the number of products that input / output each process) is stored in the control means 14 together with time information for each process, so that each time is based on the time of the product lot boundary in the final process. If the number of productions in each process is calculated, production results for each process as shown in FIG. 4 are obtained. In other words, each product and each process is separated by dividing the production performance of each process by the time corresponding to the product lot boundary based on the standard time in each process (time required for processing in each process (standard man-hour)). The lot (production time) can be made to correspond.
[0035]
In this example, it can be seen that the times when the products included in the product lot 1 pass through the process 1 are 1 to 4. Similarly, it can be seen that the time when the product of the product lot 2 has passed the process 4 is 8-11. From this, if it is made to correspond to the manufacturing data with the time for every process memorize | stored separately, the manufacturing data in each process of the product contained in each product lot can be specified. Moreover, it can confirm from the corresponding time also about the process conditions in each process.
[0036]
Therefore, when a defective product is found, the range of products that must be completely inspected or discarded can be accurately specified by performing lot tracking as described above. In addition, since the quality of the product or intermediate product can be associated with the processing conditions in each step, the minimum necessary management value in each step can be set.
[0037]
In the example shown in FIG. 4 described above, it has been described that there is no defect in each process. However, when there is a defect, it corresponds to the product lot in the same manner by using the above-described equations (1) to (3). Lot tracking can be performed.
[0038]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, the present invention is applied to a production process using a discrete continuous process for producing a plastic container. FIG. 5 shows an example of a production management system for producing plastic containers using the discrete continuous processing process according to the embodiment of the present invention.
[0039]
As shown in FIG. 5, the plastic container production process includes a plurality of raw material supply devices 20 (raw material supply device A 20a, raw material supply device B 20b, raw material supply device C 20c, raw material supply device D 20d...) A predetermined amount of raw material is supplied from the raw material supply apparatus 20 to a mixer 22 for mixing a plurality of raw materials, and processing is performed in each order of a dryer 24, molding steps 26 and 30, and packaging 28 and 32. In the present embodiment, the molding steps 26 and 30 and the packings 28 and 32 are configured to be branched into two lines, and the molding step 26 and the molding step 30 are the same raw material (the raw material supplied from the same dryer 24). ) To mold plastic containers of different shapes.
[0040]
In the mixer 22, the raw materials are mixed by stirring the raw materials supplied from the plurality of raw material supply devices 20. The raw material mixed in the mixer 22 is transported to the dryer 24 where the raw material is dried under predetermined conditions. The raw material of the plastic container dried under the predetermined conditions is supplied to the molding steps 26 and 30. .
[0041]
In the molding steps 26 and 30, predetermined conditions (pressure, temperature, humidity, etc.) are applied to the supplied raw material to melt the raw material, and the molten raw material is injected from the gate of the mold. Then, after a predetermined amount of raw material is injected into the mold, it is cooled under predetermined conditions, and after the product is discharged from the mold, a plastic container is molded through several steps.
[0042]
The plastic containers molded in the molding steps 26 and 30 are conveyed to the packings 28 and 32 and packed in units of a predetermined number.
[0043]
In each step, as shown in FIG. 3 described in the embodiment, the number of products including workpieces conveyed from the inlets (inlet A and inlet B in FIG. 3), defective products discharged in each step (FIG. 3). Then, the number of defective discharges A, defective discharges B1, and defective discharges B2) and the number of products conveyed from the outlets (the outlets A and B in FIG. 3) are respectively detected. In addition, the branching state is detected by detecting the mass of the product (dry raw material) branched to the respective molding steps 26 and 30 at the branch portion of the production process (between the dryer 24 and the molding steps 26 and 30). A branch state detecting means 34 is provided. Note that the branching state detecting means 34 may detect the quantity when it can be detected in the unit of quantity.
[0044]
Further, as shown in FIG. 6, each process is connected to a control device 36 that manages all processes, and information detected in each process (the number of products conveyed from the entrance, the number of defective products discharged). The number of products conveyed from the outlet, etc.) is output to the control device 36, and the processing conditions (for example, the heating temperature, injection pressure, injection amount, etc. in the molding steps 26 and 30) performed in each step are output. It is output to the control device 36. Further, in each process, manufacturing data in each process (for example, data such as raw materials used in each process) is output to the control device 36. Various information (information detected in each process, processing conditions in each process, manufacturing data in each process, etc.) output to the control device 36 is given after time information corresponding to each information is given. 36. The information detected by the branch state detecting means 34 is also output to the control device 36 after the time information is given.
[0045]
The control device 36 corresponds to the control means 14 in the embodiment of the present invention, and is composed of a computer having a CPU, a ROM, a RAM, and peripheral devices (not shown), and information obtained from each process together with time information. The production management is performed on the basis of the stored time of each process.
[0046]
Next, lot tracking by the control device 36 in the plastic container production process of this embodiment will be described.
[0047]
In this embodiment, the state of the product (product including raw materials and workpieces) flowing through the production process changes in the processes after the downstream of the molding processes 26 and 30. That is, in the process from the raw material supply apparatus 20 to the entrance of the molding steps 26 and 30, the raw material, that is, the powder, the gel-like liquid, the chip-like particles, or the like flows through the process as the product. In the subsequent downstream process, a molded product (plastic container as a product) flows through the process. Therefore, in this embodiment, each process is managed in units of mass on the upstream side of the molding processes 26 and 30, and in units of quantity on the downstream side of the molding processes 26 and 30.
[0048]
Management of processes (units 26 and 30 and packaging 28 and 32) in units of quantity is performed by calculating the production results from a predetermined reference point (for example, fresh start etc.) by the control device 36, and at the production quantity and production time. Based on this, products produced within a predetermined time can be managed on the control device 36 as a lot. That is, in the packings 28 and 32, the number of packings in which a predetermined number of plastic containers are packed is set as one lot, and in the molding steps 26 and 30, the packings 28 and 32 are set based on the number of plastic containers in the packings 28 and 32. The number of plastic containers produced by the injection molding machines 26 and 30 corresponding to one lot is set as one lot corresponding to the packings 28 and 32. As a result, the lots in the packings 28 and 32 can correspond to the lots in the injection molding machines 26 and 30.
[0049]
Further, between the dryer 24 and the molding steps 26 and 30, the dryer 24 corresponding to the mass of the material necessary for molding the plastic container set in the molding steps 26 and 30 by the control device 36 as described above. Is calculated from the number of moldings in the molding steps 26 and 30 and the branch information with time detected by the branch state detection means 34. As a result, the time for discharging the material from the dryer 24 can be specified.
[0050]
The mixer 22 and the dryer 24 are traced back according to the time when the same mass is processed (a change in the amount of water due to drying is described in the characteristic function).
[0051]
The mixer 22 manages processes in units of mass. When the raw materials are sequentially received in the same raw material supply apparatus at the first time, the second time,..., And the raw materials are dispensed according to the production, as shown in FIG. The total payout changes. Therefore, it is possible to specify the acceptance lot (how many times it is accepted) from the total amount of payouts at a certain time. For example, it is understood that the acceptance at the point A where the payout total is the second acceptance as shown in FIG. That is, the received lot can be specified from the total payout and time information. Therefore, it is possible to correspond the material receiving lot in the process of managing by the mass unit corresponding to the lot set by the injection molding machines 26 and 30.
[0052]
As described above, in the control device 36, each process corresponding to the product lot in the final process based on the production results with time information obtained from each process (such as the number of production and mass fluctuation of raw materials) and the characteristic function of each process. By setting the lot, it is possible to track the lot even in the production process in which the process of managing the quantity unit and the process of managing the mass unit are mixed. Accordingly, when a defective product is found in a certain process, the lot tracking of each process can be simulated by the control device 36 based on the defective product production time in the process in which the defective product is found. In addition, if a defect occurs in a certain process, the lot corresponding to the defective product in the downstream process is selected based on the time information obtained from each process, production results, and the standard time in each process even if production is performed as it is. Therefore, it is possible to control quality without interrupting production.
[0053]
Further, the control device 36 corresponds to the production conditions (for example, the molding temperature and molding pressure of the injection molding machines 26 and 30) and raw material data in the corresponding lot based on the result of lot tracking. It can be specified from the production time of the lot (the passing time of each process).
[0054]
Therefore, in this embodiment, even if it is not possible to put lots or other identification marks on products due to continuous mass production, lots in each process are set at each time based on information obtained from each process. As a result, the control device 36 can easily track the lot.
[0055]
In the above embodiment, the present invention is applied to a production process for producing a plastic container. However, the present invention is not limited to this and can be applied to any production process.
[0056]
【The invention's effect】
As described above, according to the present invention, the amount of an object that enters and exits each process of a plurality of processes is detected, the accumulated value is stored together with time information, and each process is performed based on the characteristic function of each process. By specifying the passage time, the processing conditions and the like in each process can be easily confirmed. Therefore, there is an effect that the state relating to the quality in each process can be easily specified regardless of the production form.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an outline of a production management system according to an embodiment of the present invention.
FIG. 2 is a block diagram for explaining the outline of each process of the production management system according to the embodiment of the present invention.
FIG. 3 is a diagram for explaining between steps;
FIG. 4 is a diagram showing an example of production results for explaining lot tracking.
FIG. 5 is a block diagram showing an example of a production management system for producing plastic containers using a discrete continuous processing process according to an embodiment of the present invention.
FIG. 6 is a block diagram showing an outline of a production management system according to an embodiment of the present invention.
FIG. 7 is a diagram showing lot tracking in the case of managing processes in units of mass.
FIG. 8 is a diagram for explaining the positioning of production forms.
[Explanation of symbols]
10 Production management system
12 Detection means
14 Control means
20 Raw material supply equipment
22 Mixer
24 dryer
26, 30 Injection molding machine
28, 32 packing
34 Branch state detection means
36 Control device

Claims (5)

A detecting means for detecting the amount of an object entering and exiting each step when forming a processed product from a raw material after passing through a plurality of steps;
Based on the detection result of the detection means, a storage for calculating a cumulative value of the amount of the product from a predetermined reference point in each process among the products that have completed each of the processes , and storing the calculation result together with time information Means,
Stored in the storage means based on a transit time when a product set in advance as a tracking target passes through a predetermined process, and at least a characteristic function indicating a process situation including a process situation in each process and a connection situation between each process. Specifying means for specifying the transit time of the product in each step other than the predetermined step of the set product from the time information and the accumulated value;
Production management system equipped with.   The storage means further stores manufacturing data in each of the plurality of processes together with time information, and the specifying means further specifies manufacturing data corresponding to the product based on the passage time of the product in each process. The production management system according to claim 1. It said detecting means, the production management system according to claim 1 or claim 2, wherein the detecting the number amount as the amount of material to the and out. It said detecting means, the production management system according to claim 1 or claim 2, characterized in that detecting the mass and the amount of those which the and out. Said detecting means further detects the environmental conditions of each step, said storage means, said environmental condition further stores with the time information, the setting the specific means, from the stored the environmental conditions in the storage unit The production management system according to any one of claims 1 to 4, wherein the environmental condition in each step of the manufactured product is further specified .

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