JPH05246514A - Procurement of necessary material in accordance with stock in specified period - Google Patents

Abstract

PURPOSE:To provide a stable material procurement to fluctuation of a production schedule of products without changing a material procurement schedule for a period in which it is already determined as far as possible by changing a material stock schedule. CONSTITUTION:When a production schedule of products is fluctuated, a material stock quantity for each day and each material in an initial material procurement schedule is determined based on the fluctuated production schedule. Next, this material stock quantity is compared with a tolerable range of the material stock quantity for each day as set for each material. When the material stock quantity for each day is within the tolerable range of the material stock quantity per day, the initial material procurement schedule is kept unchanged. In the meanwhile, in case the material stock quantity is beyond the tolerable range of the material stock quantity per day, the initial material procurement schedule is changed, thereby procurement of necessary materials is performed in accordance with the stock quantity in a specified period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for procuring necessary materials in accordance with an inventory amount within a predetermined period, and in particular, procuring materials such as parts and materials and assembling or mixing them. The present invention relates to a method of procuring necessary materials in accordance with an inventory amount within a predetermined period in order to flexibly respond to fluctuations in material requirement plans in a manufacturing industry that manufactures products.

[0002]

2. Description of the Related Art Conventionally, in the manufacturing industry, in the production of products, first, a production plan is determined, and in response to this production plan, the required amount of raw materials, parts and processing are completed when needed. It was necessary to procure materials such as goods and supply them to the production site.

Therefore, conventionally, in order to supply the required amount of material when needed, the material procurement plan has been prepared so that the material is always systematically supplied.

[0006] Conventionally, as a method of calculating a material requirement amount for creating this material procurement plan, a material requirement amount planning method (MRP = Material Requiren) is used.
tsPlanning) was proposed.

However, in the above-mentioned conventional material requirement calculation method, when calculating the procurement plan for each material requirement, the period to be calculated is uniformly decided (usually around 2 weeks), and Compare the first stock (initial stock) in the calculation target period with the standard stock (standard stock),
The leading procurement quantity in that period was adjusted to approach the standard value (standard inventory), and the subsequent plan performs processing such as lot consolidation, but basically, it is calculated according to only the required plan, and the calculation is performed. According to the procurement quantity, the target period was uniformly issued and slips such as order slips and work slips for each material were issued.

This method is illustrated below based on an actual example. Production plan for date A Required plan for X Initial stock for X Procurement plan for X 1 day 10 10 8 pieces 2 2 days 0 0 If there is 0 3 days 11 11 11 11 4 days 0 0 0 5 days 12 12 12 12 6 days 0 0 0 7 days 13 13 13 13 8 days 0 0 0 9 days 14 14 14 10 days 0 0 0 11 days 15 15 15 15 12 days 0 0 0 13 days 16 16 16 16 days 0 0 0 0 In the case of the above example, the explanation is simplified. In order to achieve the above, the product A is made up of two types, that is, one type of components, X and Y, and it is sufficient if the two types of components X and Y are prepared on the day, but only X of them is available. Shall be taken up.

The minimum inventory quantity (minimum holding inventory quantity) of the part X is 0, and it is not necessary to carry out lot grouping.

According to the above example, as is often shown in the above table, the inventory adjustment of the part X will be completed in one day.

However, in reality, the material procurement period varies depending on each material, and there are various long and short materials.
When materials are procured uniformly over the target period as in the past, there are the following problems. (1) In the case of materials whose procurement period is shorter than the uniformly determined period b) Materials will be procured earlier than the optimal procurement date, and materials will be procured in vain even if the plan can be changed. Therefore, it is not possible to flexibly respond to the change of the production plan corresponding to the demand fluctuation within the period, which hinders smooth production activities. (2) In the case of materials whose procurement period is longer than the uniformly decided period b) Materials will be procured later than the optimal procurement date, and it will not be possible to procure the necessary materials at the required time, which will hinder production. Will come.

For this reason, conventionally, in such a material,
Since materials are procured by hand, the work is complicated and mistakes are likely to occur.

(B) Moreover, in the above-mentioned uniformly determined procurement period, when the plan of the preceding period is changed, and in the next calculation process, when the production plan is changed due to fluctuation of demand, the procurement calculated by the above-mentioned manual work. Since it is necessary to constantly check whether or not the quantity is insufficient, there is a problem that not only the work amount further increases, but also the chance of making a mistake increases. (3) When the production plan of a product fluctuates a) In the past, the inventory plan was fixed and the procurement plan for materials was calculated.

Therefore, the procurement plan of materials is inevitably changed due to the variation of the production plan, and the plan of the material requirement is not fixed and is not stable. It will be inconsistent with the purpose of "determining the material procurement plan".

(B) Actually, there is a problem that the plan cannot be easily changed because the material is procured from another company or manufactured through a plurality of processing steps.

(C) As a result, in the case of the conventional calculation method, it was difficult to change the production plan of the product, and it was difficult to quickly respond to changes in demand.

The flow of calculation processing and the flow of plan confirmation (ordering) in the case of the conventional calculation method are briefly shown in FIG.

In this case, generally, the uniformly decided procurement period is divided into about two weeks.

As described above, in the conventional "material requirement plan calculation method (MRP)", the inventory plan is fixed corresponding to the product production plan, and the material procurement plan is fixed. If there is no choice but to change the production plan for the period that has already been decided, then the already decided procurement plan for each material must be changed. Method (MRP) ”cannot be calculated, and it is necessary to deal with it by special processing or manual work.

In the above example, if the uniformly decided procurement period is 2 weeks, the maximum already determined period is 4 weeks to 1 day, which is too long in today's demand fluctuation. During the period, it was not possible to flexibly respond to demand trends.

Further, if the uniformly decided procurement period is shortened, the materials for the procurement period longer than this period will relatively increase this time, and the manual procurement work will increase. Therefore, in general, in the current situation, it will be set to about two weeks.

Therefore, according to the above conventional example, each of these defects cannot respond to the most important point of flexibly responding to demand, and becomes a very large impeding factor in actual application. There was.

[0021]

In view of the problems of the prior art as described above, the main object of the present invention is to keep the stock of materials at the beginning for a period already fixed even if the production plan of the product changes. It is to provide a method for calculating a stable procurement plan while flexibly responding to changes in the plan and changing the material procurement as much as possible.

[0022]

According to the present invention, such an object is to make a production plan of a product when arranging materials such as raw materials and parts necessary for producing the product. When it fluctuates, (1) First, the daily material inventory amount for each material in the initial material procurement plan is calculated from the changed product production plan. (2) Next, the daily material stock amount of each material is compared with the allowable range of the daily material stock amount set for each material. (3) Then, if the daily material stock amount of each material falls within the allowable range of the daily material stock amount set for each material, the initial material procurement plan is not changed and is left as it is. To do.

On the other hand, the initial material procurement plan is changed only when the daily material stock amount of each material is out of the allowable range of the daily material stock amount set for each material. This is achieved by providing a method of procuring necessary materials according to the inventory quantity within a predetermined period.

[0024]

As described above, according to the present invention, when the production plan of a product fluctuates, the daily material stock amount of each material is changed by the varied production plan of the product per day set for each material. Only when the material inventory is outside the allowable range,
When the procurement plan is changed and it falls within the allowable range, the initial material procurement plan is left unchanged, so even if the production plan of the product fluctuates, the inventory plan of the material is changed. By doing so, changes in the material procurement plan will be minimized and the material procurement plan will be stable. Therefore, according to the present invention, since it is only necessary to change the material inventory plan for a predetermined period, it becomes possible to change the inventory quickly and flexibly, and it is possible to supply the required amount of material to the production site in a timely manner. It will be possible to flexibly respond to fluctuations in.

Further, according to the present invention, it is possible to always supply the required amount of material to the production site without excess or deficiency when necessary, and to facilitate production activities.

[0026]

Next, the first embodiment of the present invention will be described in detail.

In the manufacturing industry, when a product (product) is produced according to a production plan, it is necessary to constantly supply raw materials and parts necessary for producing the product to the production site without excess or deficiency. Therefore, it is required to procure raw materials and parts necessary for producing the product in a timely manner.

When procuring this material, the required amount of the material corresponding to the production amount of the product within the predetermined period is calculated in accordance with the stock amount of the material and the necessary material is procured. The method of procuring necessary materials according to the amount of inventory in the company is adopted.

In this case, according to the present invention, the necessary materials are procured according to the stock quantity within a predetermined period by the following method.

That is, when the production plan of the product fluctuates, (1) First, the daily material stock amount for each material in the initial material procurement plan is calculated from the changed product production plan. (2) Next, the daily material stock amount of each material is compared with the allowable range of the daily material stock amount set for each material. (3) Then, if the daily material stock amount of each material falls within the allowable range of the daily material stock amount set for each material, the initial material procurement plan is not changed and is left as it is. To do.

On the other hand, only when the daily material stock amount for each material is outside the allowable range of the daily material stock amount set for each material, the initial material procurement plan is changed to change the initial material procurement plan for a predetermined period. The necessary materials are procured according to the amount of inventory.

In this case, the allowable range of the daily material stock amount set for each of the above-mentioned materials is a range between the minimum stock amount (minimum held stock amount) and the maximum stock amount (allowable maximum stock amount). , When the minimum stock (minimum held stock quantity) is exceeded, the procurement plan is changed according to the stock quantity within a predetermined period, and when it exceeds the maximum stock quantity (allowable maximum stock quantity), the stock quantity is exceeded You will either cancel the order for the material or change the order.

According to the present invention, when the production plan of a product fluctuates, the daily material stock amount of each material is set to the daily material stock set for each material according to the changed product production plan. Only if it is outside the allowable range of inventory
If the initial material procurement plan is changed and the initial material procurement plan remains within the allowable range, the initial material procurement plan is left unchanged, so even if the production plan of the product fluctuates, the inventory plan of the material is changed. Can be dealt with flexibly, changes in the material procurement plan will be minimized, and the material procurement plan will be stable.

In practice, these processes are calculated at once for several thousand to tens of thousands of parts, raw materials, etc., so that the case where the procurement plan fluctuates more than necessary as in the past, and the minimum required There is a very large difference between the case where the calculation is limited to the limit fluctuation.

When the amount of data becomes large, it becomes impossible to check manually as a daily work, and in reality, the materials are procured as calculated by the computer system.

On the contrary, if it cannot be done, there is no point in using a computer system.

Considering from the viewpoint of actual business, it is much more difficult to change the procurement of the material itself. Therefore, the conventional calculation method that changes the procurement plan more than necessary and the minimum required location. With the calculation method of the present invention in which only the change is made, it becomes clear how large the difference is.

The present invention will be described in detail below with reference to the drawings for specific embodiments.

The following table illustrates one embodiment of the present invention.

In the case of the present example, in order to simplify the explanation, the product A is made up of two kinds, that is, one part each of X and Y, and the two kinds of parts X and Y are prepared on the day. It would be good if only X is taken.

Further, it is assumed that the minimum inventory quantity (minimum holding inventory quantity) of the part X is 5 and the maximum inventory quantity (allowable maximum inventory quantity) is 100.

Then, it is assumed that the production plan up to 10 days has been ordered as follows in the previous calculation processing. Date A Production plan X Procurement plan X Inventory X New procurement plan X New inventory 1 day 10 10 10 10 10 10 2 days 0 0 10 10 0 10 3 days 11 11 11 10 11 10 4 days 0 (+3) 0 10 (7) 0 7 5 days 12 12 10 (7) 12 7 6 days 0 0 10 (7) 0 7 7 days 13 (+5) 13 10 (2) 16 5 8 days 0 0 10 0 5 9 9 days 14 14 10 14 5 10 days 0 0 10 0 5 11 days 15 15 5 12 days 0 0 5 13 days 16 16 5 14 days 0 0 5 where product A gets a new order, 3 days in 4 days, 7 days Suppose that they will increase production by 5, respectively.

As a result of this plan change, the production plan of A in the above table changes as shown in the parentheses, and the procurement plan of X also changes as shown in the above table.

That is, if the production plan of X is the same as the previous time, the inventory of X on the 4th becomes 7. However, since this holds the minimum inventory of 5, the plan on the 4th does not need to change.

However, in the next 7-day increase in production, if the procurement of X is not changed, the inventory becomes 2, which is below the minimum inventory of 5, and the inventory of X is as shown in the parentheses. Become.

Therefore, for the stock of X, it is necessary to change the procurement plan of X on the 7th to 13 + 3 = 16. Then, the inventory also changes to 5 (= minimum inventory).

Calculations will be carried out for the subsequent steps, but other than that, there is no problem with the previous plan.

As described above, for the period of the previous order, it is sufficient to calculate based on the ordered plan and change the plan only when necessary.

Therefore, the new inventory plan is as shown in the following table. Date A Production plan X New required plan X New inventory plan X New procurement plan 1 day 10 10 10 10 10 2 days 0 0 10 0 3 days 11 11 11 10 11 4 days 0 (+3) 3 7 0 5 days 12 12 7 12 6 days 0 0 7 0 7 7 days 13 (+5) 18 5 16 8 days 0 0 0 5 0 9 days 14 14 5 14 10 days 0 0 5 5 0 11 days 15 15 5 15 15 12 days 0 0 5 5 0 13 days 16 16 5 16 14 days 0 0 5 0 When this method is represented by a flowchart, it becomes as shown in FIG.

However, this flowchart describes the processing after the necessary plan for a certain component is calculated, as in the above calculation example.

According to the method of the present invention, since the procurement plan of each material is associated with the production plan of the product through the inventory plan, independence is created and the production plan of the product is not unnecessarily swayed by fluctuations in the production plan. I will be done.

Further, it becomes possible to set an ordering period (reference period) for each material.

(In the case of the conventional material procurement method, since the concept of the allowable range of the inventory plan is not included in the daily calculation, the product production plan and the material procurement plan are uniquely linked to each other. In the calculation period, it was not possible to handle the plans that had already been fixed and the plans that had not been fixed in a mixed manner.) Next, referring to Fig. 2, the problem of the standard period for material procurement will be explained in more detail. explain.

In this case, some of the materials used are
There are various materials such as materials with short lead time that are delivered immediately after ordering, and materials with long lead time that are delivered 3 or 4 months after ordering.

Since the conventional calculation method can process only for a uniform reference period, for a material with a long delivery time, the timing of material procurement is too late. I was procuring things that I didn't need to do.

However, in the present invention, since the reference period can be set for each material, the above-mentioned conventional problems can be solved.

That is, necessary materials are provided at a necessary time,
Since we procure only the necessary quantity, it is possible to place an order at the most appropriate time.

Further, as a result, according to the calculation method of the present invention, it is possible to make the calculation target from today, and it is possible to quickly meet the demand of the customer.

Even in the case where a result that the procurement plan for the already ordered period has to be changed occurs during the above calculation, if the result is printed during the processing, the subsequent You will be able to make use of it for ordering and confirmation work. Further, if the procurement plan of the material cannot be changed, the production plan of the product can be corrected and recalculated.

Next, the second embodiment of the present invention will be described in detail.

In the second embodiment of the present invention, necessary materials are procured in accordance with the stock quantity within a predetermined period as follows.

That is, when arranging materials such as raw materials and parts necessary for producing a product and the production plan of the product changes, (1) first, the production plan of the changed product Calculate the daily stock of materials for each material in the initial material procurement plan. (2) Next, the daily material stock amount of each material is compared with the allowable range of the daily material stock amount set for each material. (3) Then, if the daily material stock amount of each material falls within the allowable range of the daily material stock amount set for each material, the initial material procurement plan is not changed and is left as it is. To do.

On the other hand, only when the daily material stock amount of each material is outside the permissible range of the daily material stock amount set for each material, the ordered procurement plan (initial material In the first embodiment, in which the procurement plan) is changed to procure necessary materials according to the stock amount within a predetermined period, according to the length of the procurement period of each material, according to the procurement period of the corresponding material. It decides the standard period of time, calculates the daily required inventory of materials for the entire period, and procures only the necessary materials within the standard period of the corresponding material.

The plan within the period thus procured is stabilized by the calculation method of the first embodiment even when the production plan of the product changes in the next calculation process.

According to this embodiment, since the material is procured for the optimum procuring period and the material can be procured at the optimum timing, the required amount of the material can be supplied to the production site in good timing, and the fluctuation of the demand can be achieved. And can respond flexibly.

In addition, it is possible to prevent in advance the trouble that the chance of making an error increases due to the increased work amount due to the material procurement at an unnecessary time or the material procurement by the manual work due to the change of the production plan. become able to do.

Moreover, the material procurement plan must be uniquely changed in response to the conventional fluctuations in the production plan.
It is possible to prevent in advance a problem in which it is not possible to respond quickly and flexibly, and complicated work such as special processing and manual work constantly occurs, which hinders smooth production activities.

Next, the third embodiment of the present invention will be described in detail.

In the third embodiment of the present invention, the required materials are procured in accordance with the stock quantity within a predetermined period as follows.

That is, when arranging materials such as raw materials and parts necessary for producing a product and the production plan of the product changes, (1) first, the production plan of the changed product Calculate the daily amount of material stock for each material in the initial material procurement plan from. (2) Next, the daily material stock amount of each material is compared with the allowable range of the daily material stock amount set for each material. (3) Then, if the daily material stock amount of each material falls within the allowable range of the daily material stock amount set for each material, the initial material procurement plan is not changed and is left as it is. To do.

On the other hand, only when the daily material stock amount of each material is out of the allowable range of the daily material stock amount set for each material, the ordered stock plan of the corresponding material (initial material Procurement plan) is changed to procure necessary materials according to the inventory amount within a predetermined period, in the first embodiment, according to the required amount of each material within the reference period calculated for each material. The necessary materials are procured by issuing slips such as order slips and work slips for each applicable material.

According to this embodiment, it is possible to smoothly procure necessary materials by issuing slips such as order slips and work slips for each applicable material at an optimum timing, and therefore, it is possible to obtain the necessary material in good timing. It is possible to supply the required amount of materials to the production site and flexibly respond to demand fluctuations.

Further, it is possible to prevent the occurrence of the trouble that the chance of making an error increases due to the increased work amount by procuring the material at an unnecessary time or procuring the material by the manual work due to the change of the production plan. It is possible to facilitate production activities.

[0074]

As described above, according to the present invention, the period of the previous order is calculated based on the ordered inventory plan, and the initial material procurement plan is changed only when necessary. As a result, there is an advantage that the material procurement plan can be stabilized against changes in the product production plan.

That is, according to the method of the present invention, since the procurement plan of each material is associated with the production plan of the product through the inventory plan, independence is created, and the production plan of the product is unnecessarily allocated to the fluctuation of the production plan of the product. It will be unnecessary.

Also, depending on the length of the procurement period of each material,
In order to procure necessary materials, it is possible to place an order for materials at the optimum timing, and it is only necessary to change the material procurement plan within the standard period, and the initial material procurement plan can be changed quickly and flexibly, so demand fluctuation There is an advantage that it can respond flexibly to.

Further, in the case of the conventional “material requirement planning calculation method (MRP)”, the number of materials is increased by procuring the material at an unnecessary time or by procuring the material manually due to a change in the production plan. There is an advantage that it is possible to solve the problem that the chance of making an error increases depending on the amount of work.

Further, in the case of the conventional "material requirement planning calculation method (MRP)", in response to the fluctuation of the production plan,
We have to change the material requirements. However, in reality, the initial material procurement plan cannot be easily changed, and complicated processing such as special processing and manual work is constantly occurring, which hinders smooth production activities. There is an advantage that the problem of the “plan calculation method (MRP)” can be solved.

Therefore, according to the present invention, when the production plan of the product changes, the calculation is made based on the procurement plan of the ordered initial material, and only when necessary, the initial material procurement plan is calculated. Therefore, it becomes possible to clarify the problem and take measures to solve the problem.

In practice, these processes are calculated at once for several thousand to tens of thousands of parts, raw materials, etc. Therefore, when the procurement plan fluctuates more than necessary as in the past, and the minimum required There is a very large difference between the case where the calculation is limited to the limit fluctuation. When the amount of data becomes large, it becomes impossible to check it by hand as a daily work, and in reality, the material is procured as calculated by the computer system. On the other hand, if you can't do that, it makes sense to use a computer system. From the point of view of the actual business, it is even more difficult to change the procurement of the material itself, so the conventional calculation method that changes the procurement plan more than necessary and the minimum necessary parts are changed. With the calculation method of the present invention, it becomes clear how large the difference is.

[Brief description of drawings]

FIG. 1 is a flowchart showing a method for procuring necessary materials according to an inventory amount within a predetermined period according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a reference period for ordering materials in the case of a method of procuring necessary materials according to an inventory amount within a predetermined period according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a flow of calculation processing and a flow of confirming a plan in the method of procuring necessary materials in the conventional example.

Claims (4)

[Claims] 1. When arranging materials such as raw materials and parts necessary for producing a product and the production plan of the product changes, (1) first, the production plan of the changed product. Calculate the daily stock of materials for each material in the initial material procurement plan. (2) Next, the daily material stock amount of each material is compared with the allowable range of the daily material stock amount set for each material. (3) Then, if the daily material stock amount of each material falls within the allowable range of the daily material stock amount set for each material, the initial material procurement plan is not changed and is left as it is. To do. On the other hand, within the predetermined period characterized by changing the initial material procurement plan only when the daily material stock amount for each material is outside the allowable range of the daily material stock amount set for each material A method of procuring necessary materials according to the amount of inventory. [Claim 2] A reference period corresponding to the procurement period of the corresponding material is determined according to the length of the procurement period of each material, and the daily required inventory amount of the material for the entire period is calculated, The method for procuring necessary materials according to the inventory quantity within a predetermined period according to claim 1, characterized in that only the standard period is procured. 3. By issuing a slip such as an order slip or a work slip for each applicable material in accordance with the daily required inventory amount of each material within the reference period calculated for each material, The method for procuring necessary materials according to the inventory quantity within a predetermined period according to claim 2, characterized in that necessary materials are procured within a reference period. 4. The allowable range of the daily material stock amount set for each material is the minimum daily stock amount (minimum holding stock amount) and the maximum stock amount (allowable maximum stock amount) set for each material. The method for procuring necessary materials according to the amount of stock within a predetermined period according to claim 1, characterized in that