Patent Publication Number: US-2004049415-A1

Title: System and method for rescheduling procurement according to altered demand

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] This invention relates to systems and methods for rescheduling procurement according to altered demand, and more particularly to systems and methods which automatically calculate demand for material in preset procurement time spans and generate new material purchase orders according to the calculated demand for material.  
       [0003] 2. Description of Related Art  
       [0004] Most large manufacturing enterprises employ a material requirement planning (MRP) system to manage their material requirements and material procurement. Many popular ERP systems on the market provide functional modules needed for MRP. Such systems include SAP R/3 from SAP, SyteLine from Symix computer system Inc., and so on. Such MRP systems help enterprises collect material requirement data and schedule material procurement in time.  
       [0005] With the numerous diversification of business transactions, purchase orders released by customers are frequently modified or canceled according to new market demand. When a purchase order from a customer is modified, a corresponding material procurement schedule must be modified accordingly. However, most existing MRP systems cannot efficiently handle the problems raised by material procurement rescheduling. For example, when modifying a material procurement order, the MRP module of SAP R/3 only provides the functions of either resetting or canceling a delivery date of the material procurement order. If only a part of the material procurement order needs to be canceled or if the material procurement order is divided into several new material procurement orders, SAP R/3 cannot satisfactorily handle such matters.  
       [0006] Accordingly, what is needed is a system and method which can overcome the abovementioned problems.  
       SUMMARY OF THE INVENTION  
       [0007] A primary object of the present invention is to provide a system which automatically calculates demand for material in preset procurement time spans and generates new material purchase orders according to the calculated demand for material and according to supply.  
       [0008] Another object of the present invention is to provide a method which automatically calculates demand for material in preset procurement time spans and generates new material purchase orders according to the calculated demand for material and according to supply.  
       [0009] To achieve the above-mentioned primary object, a system of the present invention for rescheduling material procurement comprises: a production planning module for scheduling production and generating production scheduling sheets according to received purchase order modifications; a material management module for managing inventory data and bill of material data stored in a database; and a procurement rescheduling module for rescheduling material procurement according to the production scheduling sheets. The procurement rescheduling module comprises a time span management submodule for managing procurement time spans for different materials, a demand calculation submodule for calculating revised demand for materials in each procurement time span, a delivery date calculation submodule for calculating delivery dates for materials procurement according to the production scheduling sheets, and a material purchase order generating submodule for automatically generating revised material purchase orders.  
       [0010] To achieve the other above-mentioned object, a method of the present invention for rescheduling material procurement comprises the following steps: receiving a purchase order modification from a customer; calculating a total demand for material for a plurality of preset procurement time spans; calculating a balance of material according to the total demand for material and supply of material; determining a delivery date for material required for each procurement time span; and generating and sending out a revised material purchase order.  
       [0011] Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of a preferred embodiment of the present invention with attached drawings, in which: 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0012]FIG. 1 is a schematic diagram showing structure and data interchange of a procurement rescheduling system in accordance with the preferred embodiment of the present invention;  
     [0013]FIG. 2 is a schematic diagram of main function submodules of a procurement rescheduling module of the procurement rescheduling system of FIG. 1;  
     [0014]FIG. 3 is flowchart of a method for implementing the procurement rescheduling system of FIG. 1; and  
     [0015]FIGS. 4 through 7 are exemplary tables generated in relation to a process for rescheduling a material purchase order according to the method for implementing the procurement rescheduling system as disclosed in FIG. 3. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0016]FIG. 1 is a schematic diagram showing structure and data interchange of a procurement rescheduling system  20  in accordance with a preferred embodiment of the present invention. The procurement rescheduling system  20  comprises a production planning module  30 , a material management module  31 , a procurement rescheduling module  32 , and a database  33 . A client management information system (MIS)  10  electronically connects to the procurement rescheduling system  20 , and sends purchase order (P.O.) modifications  100  to the production planning module  30  via a network (not labeled). Each purchase order modification  100  is for modifying a purchase order previously released.  
     [0017] The production planning module  30  is for receiving the purchase order modifications  100  sent by customers, and generating production rescheduling sheets  102  according the received purchase order modifications  100 . The production rescheduling sheets  102  are sent to the material management module  31 , which then retrieves inventory data  106  and bill of material (BOM) data  104  stored in the database  33  according to the production scheduling sheets  102 . The procurement rescheduling module  32  reschedules material procurement according to the production rescheduling sheets  102  and inventory data  106 , and sends out revised material purchase orders  108 .  
     [0018]FIG. 2 is a schematic diagram of main function submodules of the procurement rescheduling module  32  of the procurement rescheduling system  20 . The procurement rescheduling module  32  comprises a time span management submodule  321 , a demand calculation submodule  322 , a delivery date calculation submodule  323 , and a material purchase order generating submodule  324 .  
     [0019] The time span management submodule  321  defines time spans in which required materials are to be procured. Different materials have different time spans for procurement. Each material has a standard procurement time span, on which an actual time span for procurement is based. For example, an important and expensive material may have a standard procurement time span of 10 days, and a common material with a lower unit price may have a standard procurement time span of 30 days.  
     [0020] The demand calculation submodule  322  recalculates demand for materials according to purchase order modifications  100  and inventory data  106 . For example, a purchase order previously released by a customer may be divided into several new purchase orders, or may be modified as to quantity or delivery date. The demands for materials in various actual time spans are modified in accordance with the purchase order modifications  100 .  
     [0021] The delivery date calculation submodule  323  recalculates material delivery dates according to purchase order modifications  100 . Generally, there is a lead time for material procurement before a purchase order is released to production departments for production. The material delivery dates are determined by the lead times and production schedules of corresponding purchase orders.  
     [0022] The material purchase order generating submodule  304  is for generating revised material purchase orders  108  according to purchase order modifications  100  released by customers.  
     [0023]FIG. 3 is flowchart of a method for implementing the procurement rescheduling system  20  according to the preferred embodiment of the present invention. In step  301 , the procurement rescheduling system  20  receives a purchase order modification  100  sent from a customer. The production planning module  30  reschedules production according to the purchase order modification  100 , and sends a production scheduling sheet  102  to the material management module  31  and the procurement rescheduling module  32 .  
     [0024] In step  302 , the procurement rescheduling module  32  compiles demands for materials covering various actual time spans, according to the production scheduling sheet  102 . The actual time spans for each material are different from the actual time spans for other materials, and each actual time span starts on a day that a material is ordered. For example, a material “A” has a standard procurement time span of 30 days, and is required as follows: 1000 pieces on September 5 th , 500 pieces on September 10 th , 2000 pieces on November 15 th , and 1000 pieces on November 30 th . The procurement rescheduling module  32  defines a first actual time span from September 5 th  to October 5 th , and a second actual time span from November 15 th  to December 15 th . In the first actual time span, the demand for material “A” is 1500 pieces (1000 pieces on September 5 th  and 500 pieces on September 10 th ). Similarly, in the second actual time span, the demand for material “A” is 3000 pieces (2000 pieces on November 15 th , and 1000 pieces on November 30 th ).  
     [0025] In step  303 , the procurement rescheduling module  32  calculates a quantity of material to be canceled or added in each actual time span. When a purchase order released by a customer is modified, the corresponding material purchase order is modified accordingly. For example, if a modified demand for material “A” is 1000 pieces, and 2000 pieces of material “A” are ordered by an original material purchase order in a same actual time span, the procurement rescheduling module  32  cancels 1000 pieces of material “A” in a revised material purchase order  108  for that actual time span. Similarly, if the original material purchase order is insufficient to meet the modified demand for material for that actual time span, the procurement rescheduling module  32  adds to the demand for material in the corresponding revised material purchase order  108 .  
     [0026] In step  304 , the delivery date of material procurement is determined. The delivery date of material procurement is calculated according to production schedules of the purchase order modification sent by the customer. Lead time and off days are also taken into consideration when determining the delivery date. For example, if a material “A” is required on September 10 th , the lead time is 3 days and the off days are 2 days, and so the delivery date of material “A” is set at September 5 th .  
     [0027] In step  305 , the procurement rescheduling module  32  generates a revised material purchase order  108 , and sends the revised material purchase order  108  to one or more relevant suppliers.  
     [0028]FIGS. 4 through 7 are exemplary tables generated in relation to a process for rescheduling a material purchase order according to the method for implementing the procurement rescheduling system as disclosed in FIG. 3. Referring to FIG. 4, an original material purchase order no. XXX orders 1000 pieces of material having part no. B01. The delivery date is Oct. 1 st  2002. The standard procurement time span of the material is 30 days. No inventory of the material is on hand.  
     [0029] Referring to FIG. 5, the customer&#39;s purchase order is modified, and the demand for material becomes: 100 pieces on Sep. 10 th  2002, 200 pieces on Dec. 1 st  2002, and 500 pieces on Jan. 20 th  2003. The procurement rescheduling module  32  recalculates material demand and material supply in each actual time span according to the customer&#39;s purchase order modification  100  and the original material purchase order. In the first actual time span, from Sep. 10 th  2002 to Oct. 10 th  2002, the material demand is 100 pieces and the supply is 1000 pieces (from the original material purchase order having the delivery date of Oct. 1 st  2002). In the second actual time span, from Dec. 1 st  2002 to Dec. 30 th  2002, the material demand is 200 pieces and the supply is 0. In the third actual time span, from Jan. 20 th  2003 to Feb. 19 th  2003, the material demand is 500 pieces and the supply is 0.  
     [0030] Referring to FIG. 6, the original material purchase order is modified to meet actual demand for material. The 1000 pieces of material ordered by the original material purchase order are apportioned into the three actual time spans in accordance with the demand of each actual time span. The net surplus 200 pieces are canceled.  
     [0031]FIG. 7 shows the content of the corresponding revised material purchase order  108 . The delivery dates are determined according to the first day of each actual time span, brought forward by lead time and off days that need to be taken into consideration. As shown, the first actual time span is from Sep. 10 th  2002 to Oct. 10 th  2002. The lead time and off days are respectively 3 days and 2 days, a total of 5 days. Accordingly, the delivery date of the material required for the first actual time span is Sep. 5 th  2002.  
     [0032] The preferred embodiment described herein is merely illustrative of the principles of the present invention. Other arrangements and advantages may be devised by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the present invention should be deemed not to be limited to the above detailed description, but rather by the spirit and scope of the claims which follow and their equivalents.