The present application claims priority from Japanese application JP2007-288005 filed on Nov. 6, 2007, the content of which is hereby incorporated by reference into this application.
This invention relates to a technique for supporting a person in charge of the production planning to form/correct the production plan, or in particular to a system for supporting the change in the production plan to suppress the increase in the amount of the inventory assets by indicating what is a changeable production plan or an increased amount of the inventory assets in the case where the production plan for which the order has already been received is changed downward.
What is called a MRP (Material Requirements Planning) exists as a means of the material procurement planning which was proposed in the 1970 in US and which has recently come to find wide application. According to this method, a plan is formed to purchase or produce the required auxiliary items such as assemblies, parts and raw materials in the required quantity to meet the delivery time as required, based on the information including the production plan or the merchandising plan formed in terms of the product, the parts list, the stock/ordered amount (backlog). In the MRP calculation, an arrangement plan is formed by calculations to purchase and produce the required objects (items) to the required degree (in the required quantity) at the required time point (required to meet the delivery time) based on the production plan formed in terms of product (master production schedule, hereinafter referred to as MPS). Specifically, the lead time of each process is subtracted from the product delivery time (production plan in terms of the product) thereby to calculate the required time and the required quantity for each item of parts and raw materials (production plan in terms of the process). The MRP calculation normally requires three types of information including the MPS data, the part list and the stock/backlog data.
The MPS data is generally defined as a data indicating the production plan (how many products are required by when) of the item at the top level (i.e. the end product) in the part development diagram indicating the relation between the various parts of the product along the basic production procedure. The MPS is also called the standard production schedule.
The part list normally includes two master data of “item data” and “product configuration data”. The item data is a table containing the information unique to each item such as the time required to produce or purchase a particular part (hereinafter referred to as “the lead time”). The product configuration data, on the other hand, is the information indicating the relation between items, i.e. the product-to-part relation, the part-to-part relation and the part-to-material relation, or specifically, the information including a given item (called a parent item), a part required for producing the particular parent item (called a child item as an item underlying the parent item), and the quantity of each child item (called the constituent number of child item) required for producing a single particular parent item.
The stock/backlog data indicates the present quantity of the stock and the stock in process of each item, and the expected delivery time and the expected quantity (backlog information) of each item already ordered for future delivery.
The MRP calculation includes the following five types of calculations on each item based on the information described above.
The data on the required quantity of each item to be processed is read and the required quantity is determined for each period thereby to calculate the total required quantity for each period. To facilitate the understanding in the description that follows, assume that the period is one day and the plan is formed daily.
Based on the total required quantity calculated, the stock and the order backlog are reserved, and by subtracting the stock and the order backlog, the actually required quantity, i.e. the net required quantity is calculated on daily basis.
Based on the daily net required quantity thus calculated, the quantity is determined in lot size as set for each item.
From the delivery time for the quantity determined by lot, the lead time is subtracted, and the order date or the starting date for the order is calculated thereby to prepare an order.
The prepared order is developed to low-level items using the part list. Specifically, assuming that the day immediately preceding to the starting date for the order is the requirement date, the required quantity of each child item is calculated based on each child item and the number thereof required for each parent item in the product configuration data.
By executing the steps (1) to (5) described above, a plan is formed for one item. These steps are collectively called the part development calculation. The MRP calculation is the part development calculation process (MRP development) executed for all the items, sequentially from highest to lowest level, registered in the part list and required for production of all the products set in MPS. In the case where the merchandising plan and the estimated actual sales quantity are different from each other, an inventory calculation simulation method for accurately predicting the future inventory is available, in which the time point constituting the basis of the MRP calculation is advanced into the future and the MRP calculation is made for each time point so that the stock is calculated from the warehousing/shipment quantity thereby to determine the stock change for each time point. (see JP-A-2004-161437).
In the prior art, the future change in the inventory can be calculated using the production plan formed at the present time. It is difficult, however, to know the detailed information on each production plan such as what is a changeable production plan or what is a production plan for which many parts are already ordered. Conventionally, therefore, the person in charge of production planning is unable to change the production plan instantaneously to suppress the inventory increase.
Also, the sales department cannot be easily requested to promote the sale of a given product nor the material purchase department can be easily requested to shorten the procurement lead time. Thus, neither the measure nor the proposition to reduce the inventory can be carried out instantaneously.
In order to facilitate the preparation of a proposition to change the production plan for suppressing the inventory increase, a support system is required to easily grasp, in advance, how many parts are already ordered and at what future timing the parts are to be ordered with an increased order amount with respect to the production planning amount at a given timing.
In order to solve the problem described above, the object of this invention is to provide a production planning support method and a system thereof: wherein the part order timing information including when the parts required for production at a given timing are ordered or required to be ordered in the future is determined for each order timing and converted into an amount of money thereby to calculate the order amount for each order timing, the result of this calculation is formed into a graph, and the production planning amount at a given timing and the order amount of the parts required for the particular production are displayed in juxtaposition with each other for each period, so that the person in charge of the production planning can grasp, in advance, how many parts have already been ordered or to be ordered at what future timing with an increased order amount, thereby making it possible to change the production plan without increasing the inventory; and wherein the proposition of the extraneous stock ordered can determine the parts of which the material purchase department is requested to shorten the procurement lead time on the one hand and the products of which the sales department is requested to promote the sale on the other hand.
According to the present invention, there is provided a production planning support method and a system thereof to support the production planning of products having the parts different in procurement lead time, comprising:
a storage unit for recording the production information including the production achievement information and the production planning information, the MRP information including the initial stock information, the ordered amount information, the part list information and the various lead time information, the amount information including the product and part cost information, the expected order information, the order amount information, and the calculation result information including the production schedule and achievement amount information;
an expected order amount calculation unit supplied with the part list information, the lead time information, the initial stock information, the production planning information and the ordered amount information to calculate the expected order information;
a production planning and achievement amount/order amount calculation unit supplied with the expected order information, the initial stock information, the ordered amount information and the cost information to calculate the order amount information on the one hand and supplied with the production planning information, the production achievement information and the cost information to calculate the production planning and achievement amount information on the other hand;
a production planning and achievement amount/order timing display information calculation unit for preparing a collective order amount table collectively showing the order amount of the order amount information for the same completion date and the same order date and a collective production planning and achievement amount table collectively showing the production amount of the production planning and achievement amount information for the same completion date, and based on these information, preparing a production planning and achievement amount/order timing confirmation graph including a first bar graph with the abscissa representing the period and the ordinate the amount for showing the production amount at the position corresponding to each period and a second bar graph, displayed in juxtaposition with the first bar graph, for identifying and adding, in chronological order of the order time point, the order amounts in the collective order amount table with the particular period in a data record: and
a unit for displaying the graph.
The person in charge of the production planning can be informed of what is a changeable production plan and grasp the stock amount with the production plan changed downward with many ordered parts. In this way, the inventory increase is suppressed, and an early proposition and execution of an action is made possible thereby to reduce the risk of an increased inventory. Also, the parts of which the material purchase department is requested to shorten the procurement lead time can be determined and so can the parts of which the sales department is requested to promote the sale.
Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
A production planning support system according to an embodiment of the invention is explained below.
The storage unit (101) stores the production information (104) including the production planning information and the production achievement information, the MRP information (105) including the initial stock quantity, the ordered amount, the part list and the various lead time information required for production and part procurement which are necessary for calculation of the required quantity of the parts and the new order amount and date from the production plan, the amount information (106) containing the cost information for all the items, and the various calculation result information (107) including the expected order information containing the expected order amount and date determined by the order timing calculation unit, the order amount information, the production planning amount information and the production achievement amount information.
Also, the order timing calculation unit (102) is configured of three calculation engines including an expected order amount calculation engine (108), a production planning and achievement amount/order amount calculation engine (109), and a production planning and achievement amount/order timing display information calculation engine (110).
In the order timing display unit (103), the person in charge of the production planning reads the required data from the storage unit based on the input command for starting the system operation and calculation, conducts the three calculations of the order timing calculation unit sequentially, and holds the result of the calculations in the storage unit while at the same time outputting the result to the order timing display unit (103). The person in charge of the production planning proposes/corrects the production plan based on the result output to the order timing display unit. The invention has this system configuration.
Finally, based on the production planning amount, the production achievement amount and the order amount, the order timing calculation unit (202) calculates the production planning and achievement amount/order timing display information (206). As a result, a collective order amount table, a collective production planning and achievement amount table, and a production planning and achievement amount/order timing confirmation graph are acquired and displayed on the order timing display screen (207) of the order timing display unit (203). A series of processes are traced above according to the invention.
Next,
First, the part list (301), the lead time (302), the initial stock quantity (303), the production plan (304) and the ordered amount (305) are input to calculate the expected order amount (306).
First, the various input files are explained.
Using the file information shown in
Next, an explanation is given about the production planning and achievement amount/order amount calculation (308) corresponding to the process of the second step in the order timing calculation unit shown in
In the first part of the step, the quantity data including the expected order information (307), the initial stock (303) and the ordered amount (305) determined by the expected order amount calculation (306) is multiplied by the cost information (309) providing the amount data per item to prepare the order amount information (310).
The second part of the step executed for the production planning and achievement amount/order amount calculation (308) is to prepare the production planning and achievement amount information (312) by multiplying the quantity data including the production plan (304) and the production achievement information (311) by the cost information (309) providing the amount data per item.
Finally, the production planning and achievement amount/order timing display information calculation (313) which is the third step of the process executed by the order timing calculation unit shown in
As described above, the production planning and achievement amount/order timing confirmation graph (316) shown in
Also, the accumulation polygonal graphs of
The polygonal graph of the total order amount at time point n+1, on the other hand, indicates the order amount of the parts required to be ordered before time point n+1 to fulfill the production schedule for each period. This graph is prepared in the same manner as that for time point n.
Specifically, assuming that the time point n−1 is the beginning of the period and the time point n+N the end of the period, the total order amount at time point n+N corresponds to the total order amount for the current period. By comparing the total order amount at each time point with the total order amount at time point n+N, therefore, it is understood that about one half of the total order amount for the current period is ordered by time point n.
Also, observation of this graph indicates which production plan is difficult to change (a plan for which many parts required for production are already ordered), and therefore, the sales department can be requested to promote the sales. Further, the order amount at each time point can be grasped in detail, and therefore, it is understood that regardless of a future plan, a large amount of order is issued at an early time. With regard to such items, the material purchase department can be requested to shorten the procurement lead time, while at the same time making it possible to present the effect of reducing the inventory.
According to this invention, the person in charge of the production planning specifies a changeable production plan at the time of forming/correcting a production plan. Also, a support system is realized whereby the stock amount can be easily grasped in the case where the production plan with many parts already ordered is changed downward.
It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.
Number | Date | Country | Kind |
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2007-288005 | Nov 2007 | JP | national |