JPH03104544A - Planning support device for production schedule - Google Patents

Abstract

PURPOSE:To facilitate the preparation and change of the operation schedule of each stage and to evaluate the adequacy of the schedule by giving the instruction for the correction of a production program so that the flowing in and out quantities for the specific time of each buffer satisfy the specific equation by a displaying production program or curve. CONSTITUTION:A production or shipping state is composed of a reaction stage 1, a continuously operating separation/drying stage 3, product charge stage 5 and product shipment stage 7, and a buffer is composed of a reaction liquid store tank 2, product store tank 4 and product warehouse 6. A production program is then corrected so that the relation of an equation I may be satisfied, where the relation of a flowing-in quantity fin(t) and flowing-out quantity fout(t) at the time (t) of each buffer takes an initial store quantity as S0 and the storing quantity at the time (t) as S(t), in a production program or an accumulation curve(ACC). Also, the adequacy of the schedule can be evaluated by looking at the ACC.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a production schedule planning support I1 device. [Prior art] The production schedule for this type of multi-step process is determined by the production manager based on the estimated shipment volume of each product, the production capacity of each process, and the storage capacity of buffer parts such as storage tanks and warehouses. Based on their experience and intuition, they had formulated a production plan (schedule) that included production, production volume, schedule, and variety switching for all processes.

[Problem to be solved by the invention] By the way, the reason why buffers are provided between production processes is mainly to ensure that the operation of each process is not restricted by the previous or subsequent process, but if for some reason the production plan is not restricted. There may be cases where it is necessary to change the department. In such cases, changing only a part of the schedule may cause insufficient capacity in some buffers, or the capacity of the production process may not be fully utilized. In order to avoid such an uneconomical situation, it is necessary to create the entire production schedule again, but conventionally, this correction work required a great deal of effort and time.

The present invention solves the above problems, and makes it possible to easily create and change the operation schedule for each process in a multi-process process with buffers in between.
It is an object of the present invention to provide a production schedule planning support device that can correctly evaluate the validity of a schedule.

[Means for Solving the Problems] In order to achieve the above object, the present invention produces a wide variety of products consisting of a plurality of consecutive production processes and buffers such as storage tanks located before and after these production processes. A production schedule planning support device in a process, which includes means for creating a production plan for a production process preceding or following a buffer based on the estimated shipment amount for each product type or the storage capacity of a certain buffer; means for creating an accumulation curve for the outflow or inflow of products in a buffer at the front or rear stage of the production process based on the plan; means for sequentially repeating the production plan and accumulation creation; and creation by each of the above means. A display means for displaying the production plan and curve, and in the displayed plan or curve, at least the relationship between the inflow amount f, (1) and the outflow amount n fout (t) at time t in each buffer is determined as the initial storage amount. S. When the amount of storage at time t is S (t), fin(t)
+S −f (t)=S(t)≧0+n'
The apparatus is equipped with a production plan changing means for giving an instruction to correct the production plan created as described above so that the relationship ``o out'' is satisfied.

[Operation] According to the above configuration, a production plan for each process is created for each product type, and an accumulation curve is created from the inflow and outflow amounts of products to each buffer. Display this accumulation curve, evaluate the validity of the schedule by looking at it, and if the production plan needs to be revised, give instructions to re-build the production plan and rebuild the production plan based on it. An accumulation curve is created at . In this way, an appropriate production schedule can be created.

[Example] FIG. 1 shows an example of a process to which the present invention is applied.

This process consists of a series of four production or shipping steps and three buffers between these steps. That is, the production or shipping process consists of a reaction process 1, a continuously operated separation/drying process 3, a product filling process 5, and a product shipping process 7, and the buffer is a reaction liquid storage tank 2,
It consists of a product storage tank 4 and a product warehouse 6. A plurality of continuous steps consisting of a reaction step 1, a storage tank 2, a separation/drying step 3, and a storage tank 4 are provided in parallel. Note that the term "process" includes cases in which a series of processes merges with a process in another column in the middle of a series of processes. Also, in each series of processes,
Producing various varieties and even in one process,
The product type is also switched as appropriate.

Figure 2 is a specific process example showing the flow of various devices and products corresponding to each step of the above process. In the figure, the polymerization machine carries out the reaction process 1, the mixing tank BDT carries out the reaction liquid storage tank 2, the dryer carries out the separation/drying process 3, the hopper carries out the product storage tank 4, and the flexible container for lorry shipping (FC)
), a flexible container for unpacking (FC), and a paperback (PB) each undergo the filling process 5.

By the way, the present applicant has previously proposed that the operation plan for multi-product production can be determined using a cumulative curve (accumulation curve, hereinafter referred to as ACC) of the production volume and shipping volume for each product. However, the points to be considered when applying this concept to the operation plan for each step in a multi-step production process are explained below.

The operation plan for each process uniquely determines the ACC of the amount of flow into the buffer immediately after, given the processing speed in that process. In addition, the ACC of the outflow amount from Badufa is nothing but the operation schedule of the next process.

At this time, the ACC of the inflow and outflow in each buffer
must satisfy the following relationship.

fin(t)+S−f(t)=S(t)≧0
+n O out...(1) Here, f (t): ACC1n of inflow amount f (t): ACC of outflow amount Out So: Initial storage amount S(t): Storage amount at time t of each process No matter how good the driving schedule is on its own, (1)
If the formula is not satisfied or if S (t) is large, the schedule as a whole cannot be said to be good. One of the purposes of providing a buffer between processes is to ensure that the operation of each process is not restricted by the preceding and succeeding processes, but the constraint condition of equation {1} must be satisfied.

fio in equation (1) representing the operation schedule of each process is the production (processing) of that process. ! It is obtained by applying the ACC of i. This ACC must be created within a region determined by f, which is predicted or created in advance, the capacity of the next buffer, target production volume, production (processing) capacity, etc.

The operating schedule is ultimately determined based on evaluations of product type switching, inventory levels, etc. Among these, the evaluation regarding inventory is to reduce any one of the integral value, maximum value, and final value of S(t) in equation (1). For this, f1o
Ya f. It is possible to change the shape of u1 itself, but simply leave the shape as it is and delay f, or change f
By accelerating +n out, the evaluation can be improved. In order to further improve the evaluation, it may be necessary to sacrifice the evaluation regarding product switching.

FIG. 3 shows the construction of an embodiment of a support device for making it possible to formulate a production schedule that satisfies the above conditions.
The figure is a flowchart of the operation, and FIG. 5 shows the ACC<accumulation curve) in the hopper. In FIG. 3, the support device includes a computer control unit 11 that performs overall control, a storage device 12 consisting of ROM, RAM, magnetic disk, etc. in which various types of GLODARUM, input data, and creation data are stored, and input of various data. and an input device 13 such as a keyboard for giving instructions for modifying the created data, and a display output device 14 such as a CRT for displaying the created data.
a, and an output device 14b for printing output.

The general operation of this support device will be explained with reference to FIG. In the following example, we will estimate the progress of the product flow, that is, going back from the work plan in the filling process (filling/unpacking work plan),
It shows the upstream measurement, that is, the stage where the work plan (polymerization preparation plan) in the reaction process was created. First, after inputting various data using the input device 13 and storing them in the storage device 12, before creating a filling/unpacking work plan, the FC, P
Set the shipping curve for B (#1) and FC from the hopper.
, Determine the PB warehousing curve and lorry shipping curve (
#2, #3). Examples of these ACCs are shown in Figures 8(a) to (
C), shown in FIGS. 9(a) to (c). Further, the filling/unpacking work schedule is shown in FIG. 9(d). Based on this plan, the ACC of the total payout amount from the hopper is created (#4). As a result, the payout amount B of ACC shown in FIG. 5 is obtained. Please refer to this details
Shown in the figure.

Next, before creating a polymerization preparation plan, a product changeover schedule for the dryer located upstream of the hopper is created using the ACC concept (#5 and #6). This example is the first
Figure 1<a). Shown in (b). Next, from the polymerization reaction prescription data and lead time data in the buffer,
Create a polymerization preparation plan (#7.#8). This example is the first
This is shown in Figure 1(c). Based on this polymerization preparation plan,
From the production capacity data and lead time data, A. of the amount of product flowing into the hopper is determined. Find C (#9).

As a result, the product inflow amount B of ACC shown in Fig. 5 is obtained. The details are shown in FIGS. 12(a) and 12(b).

The above operations can be performed by displaying them on the display of the display output device 14a using a predetermined program stored in the storage device 12, and the validity of the ACC in each activated hopper can be checked based on the above conditions, etc. Evaluate based on (
#1 0, #1 1).

If the result of the evaluation is not valid, the process returns to #2 and the same operation is repeated until a valid value is obtained. This evaluation is carried out by the production planning manager on the display output device 14.
The judgment may be made while looking at the display indicated by a, and instructions for correction may be inputted as appropriate, or this judgment may be made on software using a program.

Next, details of the filling/unpacking work plan in #2 and #3 will be explained with reference to the flowchart shown in FIG.

The filling and unpacking work plan is drawn up as a discharge plan from each hopper. First, a shipping estimation curve for each type and packaging type is set (#11), and the required filling amount for each type and packaging type is set (#12). Create a work plan for filling and unpacking FC (for unpacking) and PB (#13). Check whether this plan is subject to resource constraints such as equipment and personnel (#14), and if there are any problems, return to #12 and re-create the plan. If there is no problem, proceed to #15 and create a cumulative curve of the amount removed from the hopper for each type of packaging (FC, PB).

Next, create a cumulative curve for the amount of lorry shipments (#1
6). This cumulative total is the sum of the cumulative amount removed from the hopper and the cumulative total from the bag opening FC.

Check whether these created curves are not subject to resource (equipment/personnel) constraints in the same way as above (#
17). If there is a problem, check whether the filling plan needs to be changed (#19), and if necessary, go to #12; if not, go back to #16, and repeat the same steps. If there is no problem, the filling/unpacking work plan and inventory estimation schedule curve are determined (#18), and the process returns to the main routine.

Next, the details of the polymerization preparation plan #5 to #8 in FIG. 4 will be explained with reference to the flowchart in FIG. 7.

In the above-mentioned process, the polymerization preparation plan has the most severe restrictions regarding changing the type of dryer, so the schedule for changing the type of dryer is considered with priority. First, A for each series.
Create a dryer type switching schedule by applying CC ideas (#2 1). Here, the amount dispensed from the hopper is used as the demand curve. Next, the created schedule is evaluated regarding product switching and inventory (#22, #23>. This evaluation criteria is as described above. If the schedule is not appropriate as a result of the evaluation, it is necessary to change the constraints. Check if there is one (#30).
If it is not necessary, return to #21, and if necessary, change the constraints based on the evaluation (#31),
Return to #21.

If the schedule is found to be appropriate as a result of the evaluation, then it is checked whether all the series are integrated and the constraint conditions for product switching are satisfied (#24, #25).

If not OK, return to #30, if OK, go to #26
．． Proceed to #27 and create a quality switching schedule for the polymerization machine from the prescription data and lead time data. This example is as shown in FIG. 11(c). If this schedule is not OK, return to #30, and if it is OK, #
Proceed to step 28 and evaluate consistency with the monthly plan. after that,
The polymerization preparation plan, dryer type switching schedule, and evaluation of differences from the monthly plan are determined (#29>, and the process returns to the main routine. For details on how to evaluate the schedule, for example, see Figure 12) In the ACC of the inflow i (from the dryer) to the hopper and the outflow amount from the hopper (i.e. the withdrawal amount) in (b), ACC of the inflow amount and ACC of the withdrawal amount
It is only necessary to judge whether the difference is within the capacity of the hopper and whether the inflow amount of 800 is higher than the withdrawal amount ACC, that is, whether it is larger. If this condition is met, the inventory amount in the hotsuber will never reach zero, so production will not be stopped, and the schedule can be evaluated as reasonable.

Furthermore, in the above embodiment, each ACC between the inflow i (from the dryer) and the outflow amount in the hopper is finally determined (see 15 in FIG. 12(b)). This helps the hopper evaluate the production schedule during the process.
This is because we focused on the things that show the most characteristics.

Note that the present invention is not limited to starting the schedule formulation from the earlier stage of the process as in the above embodiment, but may start from the H floor in the middle. Furthermore, the ACC to be finally evaluated is not limited to the hopper.

[Effects of the Invention] As described above, according to the present invention, in a multi-stage process with buffers between processes, individual operation schedules are displayed as a production plan/accumulation curve that includes the status and capacity of the preceding and succeeding stages. Therefore, the validity of schedules can be easily and accurately evaluated, and if there are any inconveniences between individual operation schedules, schedules can be quickly revised to achieve overall consistency. In this regard, in the past, even when a part of the schedule needed to be changed, it required a lot of effort and time to create a new entire schedule based on the experience and intuition of the production manager. Was.

Furthermore, when creating a schedule, the shape of the accumulation curve itself, that is, the amount of inflow and outflow of products, can be easily delayed or accelerated in the time axis direction while keeping the shape itself the same, which creates a buffer between processes. The amount of storage (inventory) can be reduced, making it possible to improve economic efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a production process to which the support device of the present invention is applied, FIG. 2 is a diagram showing the process, and FIG. 3 is a block diagram showing an example of the hardware configuration of the support device. , FIG. 4 is a flowchart showing the overall operation of the same device, FIG. 5 is a diagram showing an example of an accumulation curve created by the same device, and FIGS. 6 and 7 are each a part of the flowchart in FIG. 4. Flow chart showing the detailed operation of Figure 8 is a diagram showing individual accumulation curves at the shipping stage, Figure 9 is a diagram showing individual accumulation curves for inventory, and Figure 10 is an accumulation curve of the amount withdrawn from the hopper. Figure 1l is a diagram showing the accumulation curves of the dryer and mixing tank and the performance of the polymerizer, and Figure 12 is a diagram showing the accumulation curves of the inflow and withdrawal amounts of the dryer and hopper. It is. 1... Reaction step, 2.4... Storage tank (buffer),
3...Separation/drying process, 5...Filling process, 6...
Warehouse, 7... Shipping process, 11... Total Sa control section, 1
2...Storage device, 13...Input device, 14a, 14
b...Output device.

Claims (1)

[Claims] (1) A production schedule planning support device for the process of producing a wide variety of products, which consists of multiple consecutive production processes and buffers such as storage tanks located before and after these production processes. Or, based on the storage capacity of a certain buffer, a means for creating a production plan for a production process in the previous or subsequent stage of the buffer, and based on the production plan,
means for creating an accumulation curve for the outflow or inflow of products in a buffer at the front or rear stage of the production process; a means for sequentially repeating the production plan and the creation of the accumulation; and a production plan created by each of the above means. and a display means for displaying a curve and a curve; and in the displayed plan or curve, at least an inflow amount f_i_n(t
) and the outflow amount f_o_u_t(t), where the initial storage amount is S_0 and the storage amount at time t is S(t), f_i_n(t)+S_0−f_o_u_t(t)=S
(t) A production schedule planning support device comprising: production plan changing means for giving an instruction to modify the production plan created as described above so that the relationship ≧0 is satisfied.