Abstract:
A computer-implemented method to assist in managing supplier capacity to supply a supplied unit to at least a first user of the supplied unit by at least one supplier, for a series of periods, based on data as of a reference date, the series of periods being in the future relative to the reference date, comprising calculating a supplier capacity contingency ratio for each period, the supplier capacity contingency ratio for each period being a ratio between, a difference between the supplier future load for that period and the supplier reference-date available capacity for that period, and the supplier available capacity for that period. A computer-readable information storage device containing computer-executable instructions to carry out this method.

Description:
CROSS-REFERENCE 
     The present application claims priority to U.S. Provisional Patent Application No. 61/091,321 filed on Aug. 22, 2008, the entirety of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the management of supplier capacity in a supply chain. 
     BACKGROUND OF THE INVENTION 
     In many industries, original equipment manufacturers (“OEM&#39;s”) do not themselves manufacture some (or even any) of the parts of which their products are made. In some such cases, the OEM&#39;s rely on various suppliers to supply them with the parts, etc. that they need to complete the final assembly of the product. In other such cases, even the final assembly of the product is completed by a supplier (who may provide the OEM with the final product for distribution or may even directly distribute the final product through distribution networks or to final consumers). 
     The suppliers themselves will likely rely on sub-suppliers to provide them with certain parts, such that the entire supply chain can be quite complex and can include many different suppliers at many different levels (the term “suppliers” being used hereinafter to refer to both ultimate supplier(s) and any sub-supplier at any level in the supply chain). The OEM which is selling the final product may not know (unless it specifically enquires thereinto) the intricacies of their own supply chain, which may include hundreds or thousands of suppliers and sub-suppliers. 
     The relationship between an OEM and its suppliers (or between a supplier and its sub-suppliers) is rarely a one part relationship. Typically, a supplier will supply an OEM with many parts (be they related or unrelated) for more than one (and, in some cases, many) products. Furthermore, the supplier may also be supplying some (or all) of the same parts to other entities (including competitors of the OEM), for a variety of reasons. 
     Globalization adds another layer of complexity to supply chains, since the OEM&#39;s and their suppliers supplying parts, etc. for a final product, are rarely both in the same geographic region of the world (or even in the same country or continent). In many instances an OEM cannot simply drop in on one of its suppliers (let alone its sub-suppliers) whenever it decides that it needs to do so. A similar observation can be made with respect to the relationship between the suppliers and the sub-suppliers. 
     Finally, the increasing technological complexity of products only adds to this problem as it increases the number of suppliers and the depth of the supply chain. 
     Nonetheless, despite all of this, OEM&#39;s ideally need to try to ensure, at a minimum, adequate timely supply of required parts. This can be quite a challenge in the manufacturing context previously described. 
     Presently, perhaps somewhat surprisingly to those unfamiliar with the situation, there is simply no effective system to do this. What typically occurs is that an OEM will examine and approve a supplier (in terms of quality and quantity of production) at the start of their relationship with the supplier, and will periodically (for example every few years or so) audit and re-approve the supplier. In the interim, the OEM will place orders with the supplier and trust that the supplier can timely fulfill them, notwithstanding the changing needs of the OEM (and the other persons that the supplier supplies). Assuming the supplier does timely fill the OEM&#39;s orders, there is generally likely nothing to suggest to the OEM that the supplier will not be able to do so in the future. In some cases, however, notwithstanding the goodwill of the supplier and its past history with an OEM, the supplier will be unable to meet the changing future needs of the OEM. This obviously will create a problem for the OEM, yet conventionally the OEM has no vision into this problem and when and where it will occur. 
     To illustrate this point, a concrete example may be taken from the aircraft manufacturing industry. The assignee of the present application manufactures and sells various aircraft in association with the trademark AIRBUS (the present assignee hereinafter referred to as “OEM A”). For the purposes of the present patent application, some of these aircraft may be grouped into different programs of related aircraft, such as the “single aisle” (SA) aircraft program (those aircraft sold in association with the trademarks A318, A319, A320, and A321), the “long range” (LR) aircraft program (those aircraft sold in association with the trademarks A330 and A340), the “double deck” (DD) aircraft program (that aircraft sold in association with the trademark A380), the A400M aircraft program (that aircraft sold in association with the trademark A400M), the A350 aircraft program (that aircraft sold in association with the trademark A350) and the ATR aircraft program (those aircraft sold in association with the trademarks ATR42 and ATR72). 
     It will be appreciated that for any one individual part, there are several possibilities with respect to that part&#39;s use. A first possibility is that a part is used in the manufacture of every aircraft series in each of the aforementioned aircraft programs of OEM A (i.e. the A318, A319, A320, A321, A330, A340, A350, A380, A400M, ATR42 and ATR72). A second possibility is that a part is used only in the manufacture of some, but not all, aircraft series (be they all part of the same program or otherwise) by OEM A. A third possibility is that a part is used only in the manufacture of a single aircraft series by OEM A. The part may also be used by other aircraft OEM&#39;s (either with or without the knowledge of OEM A). 
     An aircraft is composed of thousands of parts. OEM A does not manufacture itself each and every one of these parts. It relies on a complex supply chain, the precise details of which are not relevant to the present application. However, solely for the purpose of illustrating some of the problems with conventional supply chains, it will be assumed (although it is clearly not the case) that each of those parts is supplied by a supplier which itself manufactures the part in question and does not rely on any sub-supplier. 
     Assuming that a part in question used by OEM A is an aircraft fuselage window, called Window Type A. Window Type A is used both for the single aisle program and for the double deck program. Window Type A is supplied to OEM A primarily by Supplier #1, but also to a limited extent by Supplier #2. Supplier number #1 also supplies OEM A with Window Type B, which OEM A uses for the long range program. Supplier #1 also supplies other OEM&#39;s, as well as individual airlines (for use as replacement parts for example), with both Window Type A and Window Type B. Supplier #1 was approved as a supplier to OEM A and in the past has been able to supply OEM A with the windows that it required. 
     However, in the current year, based on OEM A&#39;s current order book, it is forecast that the number of aircraft of each of the aircraft programs will increase on a yearly basis, although not by the same amount per program, nor the same amount year over year. Nor are these increases continuous or constant. Therefore, the number of windows of each type that the supplier will need to supply to OEM A will increase over the next few years, but not at a constant rate and not at the same rate for each type of window supplied. The other OEM&#39;s that Supplier #1 supplies may also increase their purchase of windows as well, although OEM A is unaware of the timing and quantity of such increases. OEM A obviously wants to ensure that its supply of windows can keep up with its production rates. While this may appear complex although reasonably achievable, this is but one product in an oversimplified example. The true issue is much greater than this, as OEM A wants to simultaneously ensure that its supply of all of the parts of which all of its products are made can keep up as well. 
     Conventionally, there is no effective way for OEM A to do this, i.e. to determine where and when (if any) there will be bottlenecks in its supply chain given its current forecast for its increased future needs. Presently, OEM A can simply alert all its suppliers of its forecast increased needs (both in quantity and timing) and trust that the suppliers will be able to comply. This, obviously, may have mixed results. In some cases the suppliers themselves do not understand the effect of OEM A&#39;s and others&#39; increased needs on their own business and they will not make adequate preparations to meet the increased demand. Or, they may fail to meet increased demand for a variety of other reasons. In any event, OEM A has no vision in which suppliers will have a problem in advance of the problem itself, so it cannot take steps in advance to avoid the problem from occurring or to mitigate the effects of any problems that will occur. This is an undesirable situation. 
     Therefore, there is a need in the art for an improved method to assist in managing supplier capacity to meet changing (and particularly increasing and discontinuously variably increasing) demand in a supply chain. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to ameliorate at least some of the inconveniences present in the prior art. 
     It is also an object of the present invention to provide an improved method to assist in managing supplier capacity to meet changing (and particularly increasing and discontinuously variably increasing) demand in a supply chain. 
     Therefore, in one aspect, the invention provides a computer-implemented method to assist in managing supplier capacity to supply a supplied unit to at least a first user of the supplied unit by at least one supplier, for a series of periods, based on data as of a reference date, the series of periods being in the future relative to the reference date, the method comprising:
     (a) accessing data related to a supplier reference-date load for the supplied unit for each of the periods;   (b) accessing data related to a supplier reference-date available capacity for the supplied unit for each of the periods;   (c) accessing data related to a first-user supplied-unit requirement for the supplied unit for each of periods;   (d) calculating a supplier future load for the supplied unit for each of the periods, the supplier future load being based on the supplier reference-date load for that period and the first-user supplied-unit requirement for that period;   (e) calculating a supplier capacity contingency for each period, the supplier capacity contingency for each period being defined as a difference between the supplier future load for that period and the supplier reference-date available capacity for that period; and   (f) calculating a supplier capacity contingency ratio for each period, the supplier capacity contingency ratio for each period being a ratio between the supplier capacity contingency for that period and the supplier reference-date available capacity for that period.   

     It is highly preferred that when the supplied unit is one of a group of different supplied units that each of (a)-(f) is repeated for each one of the group of different supplied units, to determine a supplier capacity contingency ratio for each one of the group of different supplied units for each period. 
     It is also highly preferred that when the supplied unit is further supplied by the supplier to at least one additional user, the data related to the supplier reference-date load for the supplied unit for each period includes data related to at least a total of each additional-user load for that period. 
     The present invention arose from the observation of several characteristics of a supplier-client relationship (which is not to imply that any or all of these characteristics must be present in any particular relationship in order for the present invention to be of utility). 
     Given the size and complexity of supply chains of global companies, the conventional method of oversight through periodic audits is inefficient, and moreover, is insufficient to ensure that suppliers in a supply chain will be able to meet increased future demand. In its most basic form therefore, the invention provides a metric against which the supply capacity of the various suppliers in a supply chain can be measured, to determine where and when the problems (i.e. bottlenecks) in the chain are likely to occur. In order to evaluate a supplier against this metric, the invention standardizes the type of information collected from each supplier and the method by which that information is processed. This standardization yields a result from each supplier that is meaningful across basically the entire supply chain, allowing a comparison of all the different suppliers in the chain with the metric. This result is referred to herein as the “supplier capacity contingency ratio” and is described in further detail herein below. 
     In the context of the present invention, a “supplied unit” is not limited to the final output from the supplier received by its client. A “supplied unit” may be the output of any production entity (i.e. a machine, a group of machines, a production line, or a particular plant), the production entity selected being the “supplier” in the present context. Hence, the term “supplier” is not limited to the conventional definition of the term. Therefore, the output of the production entity may (and in many instances, will) be an interim output and serve as the input for another production entity (typically in the same plant); this second production entity being a “user” in the present context. While the “supplied unit” must be discretely measurable (so as to yield a quantifiable total per period), it needs not be an actual unit (of course it may be). The supplied unit may thus, for example, be measured in hours, units, tons, meters, square meters, etc., whatever the appropriate unit of measure is for the output of the particular production entity selected. 
     The choice of what exactly the “supplied unit” and the production entities are (i.e. how deep does one drill down into the supply chain) depends on the level of detail at which the parties (particularly the ultimate OEM) decide that the particular supply process in question needs to be managed in order to provide a desired level of confidence in the supply capability of the supplier to the client. This choice may be based on past experience of the client, the comfort level of the client, the relative bargaining power of the parties, the nature of the part supplied, the criticality to the client of the part to be supplied, or any other criteria related to the organizations and parts involved. What is important is that less detailed “supplied-unit” choices be representative of the more detailed “supplied-unit” possible choices of which they are comprised, such that meaningful results are obtained. 
     Notwithstanding the foregoing, and solely for the purpose of ease of explanation and not intending to be limiting, the following discussion will use the term “supplier” in the conventional sense (i.e. an entity that supplies a complete part to another entity), that complete part will be the “supplied unit”, and the “first user” of the supplied unit will be the OEM whose supply chain is being managed. 
     For present purposes, time is broken down into various “periods” of more or less even length. For example, a “period” may be a month, a week, a bi-week, 10 days, or any other repeating measurable unit or group of units of time. Months are the preferred period in most contexts, since this is the unit of time by which many production schedules are measured. The present invention is concerned with a series of these periods, with the length of the series being at the determination of the parties (or one of them), again at a length that provides a desired management horizon, depending on the parties and the business concerned. Three (3) years (i.e. 36 months) is the preferred length of the series of periods. 
     On a particular date or dates, (collectively as the case may be) the “reference date” in the present context, the “supplier reference-date load” for the supplied unit for each of the periods is provided. (The “reference date” is simply the date as of which the data is up-to-date to. Ideally it would be up-to-date to the date of the assessment and thus would be current. But it may be somewhat (although insignificantly older). The “load” is the total number of supplied units that the supplier must supply during a period regardless of the supplied units&#39; destination or ultimate use. Thus, the “supplier reference-date load” may be the load (on a per period basis) that, as of the reference-date, is known. In most contexts, however, the actual reference-date load for each period is not used in calculations, but rather it is preferred (although not required) to use the average of all such actual reference-date loads for the periods for each period. (I.e. each period is assigned the average load of all the periods.) Using an average load is one way to take into account that the loads are simply forecasts and that they may change (depending on how far they are in the future) as time progresses and the future period approaches. It also takes into account that periods may always be exactly the same amount of time (e.g. not all months have the same number of days nor holidays/working days). As another alternative, the average actual user demand over a selected interval of time prior to the reference data—e.g. 1 year—on a per period basis may be used. The data related to the supplier reference-date load is typically provided by the supplier, as in most cases the supplier will be supplying entities other than the OEM, and thus only the supplier will have information related to the total load (and not just the load related to the OEM). The data provided by the supplier may or may not include the load related to the OEM (obviously the OEM has this information), it should simply be clear as to whether or not it includes this information so the load related to the OEM is not counted more than once. With respect to loads related to entities other than OEM&#39;s, it is not necessary that the data provided contain anything other than the total “other entity” load, a breakdown by particular entity (or even more detailed) is not necessary. (In many instances, a supplier will be legally unable or unwilling to provide such a breakdown in any event.) The data should incorporate as much information regarding changes to the “other entity” load over time (available on a period by period basis) as possible, in order to provide the most accurate information. The expression “load split” refers to how the supplier load breaks down between various clients (e.g. the various OEM&#39;s) and, optionally, between the clients&#39; uses as well (e.g. the various OEM programs). 
     Similarly, on a particular date or dates, (collectively as the case may be with the previously referred to dates the “reference date”), the supplier reference-date available capacity for the supplied unit for each of the periods is provided. The available capacity is preferably the actual demonstrated capacity over a selected interval of time prior to the reference date—e.g. 1 year—(on a per period basis) to supply the supplied unit under normal operating conditions (e.g. normal employee shift pattern, no overtime, no tactical subcontracting, etc.). The actual demonstrated capacity is preferred to be used, not some theoretical capacity or a demonstrated capacity under abnormal operating conditions, in order to provide a more realistic result. (Although in some situations a theoretical or other demonstrated capacity may be used.) 
     Data related to the OEM supplied-unit “requirement” for the supplied unit for each of periods is also required. The “requirement” is the total number of supplied units that the OEM will require during a particular period (for each of the periods—although the number may be zero). If the supplier reference-date load contains only up-to-date (i.e. of the date of the assessment) data related to this requirement, then for the present purposes (depending on the circumstances), that can be sufficient. What is more likely to be the case is that the data related to the supplier reference-date load will contain some data related to the OEM supplied-unit requirement, but not all. That is to say the OEM may be changing its forecasts for its future requirements from the information that is provided in the supplier reference-date load data. This might be the case either because of an actual change in its needs or because the OEM could be running a theoretical simulation to see what would happen in its supply chain should certain changes in the demand for its products occur. Thus, the data related to the OEM supplied-unit requirement may be separated by OEM use. 
     The data related to the supplier reference-date load, the supplier reference-date available capacity, and the OEM supplied-unit requirement may be provided in any form and/or format whatsoever, either physical or electronic. However, it is much preferred that the data be provided in electronic form in a standard format directly usable by a computer program (an example of which is described below) designed to implement the method of the present invention. In such cases, the data in electronic form may be provided as an electronic file or files on a computer-readable information storage device (e.g. a USB “key”), via electronic-mail, over a network, or the internet. The exact means by which the electronic file(s) is (are) provided is only important in so far as it (they) must be compatible with or be able to be made compatible with the aforementioned computer program. If the data (or any portion thereof) is provided in physical format (e.g. on paper), it will, at some point, have to be converted to an electronic format, by any number of conventional means, including optical character recognition or human data entry. 
     Once data related to the supplier reference-date load and to the OEM supplied-unit requirement has been accessed, a supplier future load for the supplied unit for each of the periods is calculated. The supplier future load is based on both the supplier reference-date load and the OEM supplied-unit requirement for a particular period, and is the combination of the “others” load and the OEM load for the period. Depending on in what format the data is stored, this may be the result of addition of two numbers or the result of a more complex mathematical formula. No particular mathematical formula is dictated by the present invention. What is important is that that total load (from all sources) is calculated. This total load is termed the “supplier future load”. 
     Next, the “capacity contingency” for each period is calculated. The capacity contingency for a period is the difference between the supplier future load for the period and the supplier available capacity for the period.  FIG. 1  shows graphically (among other things) the relationship of load, available capacity and capacity contingency. 
     Thereafter, a “supplier capacity contingency ratio” for each period is calculated. The supplier capacity contingency ratio for each period is a ratio between the supplier capacity contingency for that period and the supplier available capacity for that period. The ratio is easier to understand if expressed as a percentage, rather than as a fraction. The ratio is unit-less, and as was previously mentioned, provides a standardized result that is meaningful no matter who the supplier or what the supplied product, allowing a comparison of basically all the different suppliers in the chain with the metric. 
     To illustrate this,  FIG. 2  shows graphically a simplified example of what may happen over time if the OEM load (being the total of the shown DD, LR, and SA loads—from the previous example) on a particular supplier increases. In this simple case (as it is assumed that the “others” load and the supplier available capacity remain constant) at some point in the future, as the OEM load on the supplier increases, the capacity contingency decreases, and the supplier will at some point no longer be able to furnish enough supplied units to meet the OEM demand. 
     As was previously noted, however, conventionally, the OEM does not know to which supplier(s) this will occur (if any) and when. The supplier contingency capacity ratio assists in that it can be calculated at any given time for a multitude (or even) all of the suppliers to an OEM. Table 1 below illustrates this. 
     
       
         
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Scenario X Contingency Simulation 
               
             
          
           
               
                   
                 Production 
                 January 
                 February 
                 March 
                 April 
                 May 
                 June 
                 July 
                 August 
                 September 
                 October 
                 November 
                 December 
                 January 
               
               
                 Supplier 
                 line 
                 2007 
                 2007 
                 2007 
                 2007 
                 2007 
                 2007 
                 2007 
                 2007 
                 2007 
                 2007 
                 2007 
                 2007 
                 2008 
               
               
                   
               
               
                 Alpha 
                 Assembly 
                 12% 
                 14% 
                 14% 
                 12% 
                 8% 
                 7% 
                 3% 
                 −2% 
                 2% 
                 6% 
                 12% 
                 12% 
                 14% 
               
               
                 Beta 
                 Panel Riveting 
                 16% 
                 14% 
                 11% 
                 13% 
                 12%  
                 9% 
                 4% 
                  5% 
                 1% 
                 4% 
                  6% 
                 11% 
                 13% 
               
               
                 Alpha 
                 Machining 
                  9% 
                  6% 
                  4% 
                  2% 
                 4% 
                 7% 
                 10%  
                 11% 
                 11%  
                 12%  
                 14% 
                 16% 
                 15% 
               
               
                 Gamma 
                 Paint Shop 
                  5% 
                  3% 
                  3% 
                  4% 
                 4% 
                 6% 
                 5% 
                  6% 
                 7% 
                 5% 
                  6% 
                  8% 
                  7% 
               
               
                   
               
             
          
         
       
     
     In Table 1, the supplier capacity contingency ratio for 3 suppliers supplying 4 supplied units (i.e. unnamed output of the production line indicated) of over one-month periods of time beginning in January 2007 and going until January 2008. The actual load changes are not important in this example; what is important to note is that the load changes drive changes in the capacity contingency ratio. The larger the number, the more contingency for supply the supplier has. The smaller the number, the less contingency for supply the supplier has. 
     Moreover, the calculations leading to the supplier contingency ratio can be re-run as often as is desired using different OEM supply requirements, allowing for “what-if” scenarios to be run to determine the effect on the supply chain of various different OEM supply requirements. 
     In situations where there is more than one supplier supplying an OEM with the same supplied unit, it is highly preferred that the data related to the supplier reference-date load for the supplied unit for each of the periods includes data related to each of the plurality of suppliers; and that the data related to a supplier reference-date available capacity for the supplied unit for each of the periods includes data related to each of the plurality of suppliers. In other words, it is preferred that the multiple suppliers be treated as a single supplier factoring in each supplier&#39;s relative load and available capacity. In such cases, altering the relative proportion supplied between the suppliers may be an action that can be undertaken to increase the available capacity. Alternatively, it is possible, to treat the suppliers as separate suppliers despite the fact that they supply the same part. 
     Where the supplied unit is required by the OEM for a plurality of uses, it is highly preferred that the data related to the OEM supplied-unit requirement for the supplied unit for each of the periods includes data related to a per OEM use basis. In this manner, the invention allows the OEM to be more granular in its approach with respect to its products where the supplier is supplying the same supplied unit for a number of different OEM products. In this respect the OEM load on the supplier is split by OEM product or group of product (as the case may be). Referring to  FIGS. 1 &amp; 2 , for example, the OEM load does not appear as a single block (as does the “others” load), but rather is broken down by program (SA for Single Aisle, DD for Double Decker, and LR for Long Range—from the previous example). In this way, the OEM can run even more detailed “what-if” scenarios that do not treat all of its products as monolithic block. 
     It is highly preferred to compare the supplier capacity contingency ratio for each period with a threshold value indicative of an insufficiency in the supplier capacity contingency, to determine any periods having insufficient supplier capacity contingency. (This is the metric to which reference was previously made that allows a comparison of disparate suppliers.) Proceeding in this manner may help to focus the attention of the OEM on those suppliers having too great a risk (or even an almost certainty) of being unable to meet the OEM&#39;s requirements. The threshold value selected can depend on many factors including the nature of the product and the supplied unit and the risk tolerance of the OEM. Referring back to Table 1, the threshold value selected is 5%, thus every period in which a supplier&#39;s capacity contingency ratio is 5% or less has been highlighted, with particular highlight being given to the August 2007 period for the supplier Alpha in which the ratio is negative (−2%) (indicating a very high likelihood that the supplier will be unable to meet the OEM requirement for that period). It is also possible, as is shown in the Table to have multiple threshold values indicating different risk profiles. In this respect, supplier capacity contingency ratios greater than 5% but less than or equal to 10% have also been indicated in Table 1. 
     In most circumstances, the supplier available capacity can be increased over a certain period of time. For example, to name but a few ways: more workers can be hired, more raw material can be purchased, more machinery can be purchased, additional production lines may be added, the process may be optimized to increase efficiency, etc. Each of these remedial actions will have the effect of increasing output, although not all may be available in any given situation. Further, they will not all likely have the same effect on the supplier&#39;s available capacity, nor can they all be implemented within the same period of time. Each will have its own lead time, i.e. the minimum interval of time required for its implementation (which is rarely zero).  FIG. 3  illustrates an example of this principle in graphical form. In this example the available capacity increases over time as each of the various ways to increase capacity is implemented. 
     In view of this, it is highly preferred that each supplier provide data related (in advance) to each action that can be undertaken to change that supplier&#39;s reference-date available capacity for the supplied unit and the lead time required in order to implement those actions. (The format and form of this data being as described herein above in relation to other data.) In this manner, when desired (for example, when the supplier capacity contingency threshold is exceeded), a computer program implementing a method of the present invention will determine at least one action (and preferably more) that can be undertaken to change the supplier reference-date available capacity for a given period in time having insufficient supplier contingency. Further, based on the date of the given period in question, the program will determine, for each action, a latest action implementation date by which that action must be undertaken in order to change the reference-date available capacity in time for the given period based on the lead time for that action. 
     In this manner, when data related to a multitude of suppliers is rendered accessible and the OEM can input various different (or only one—depending on its goal) supplied unit requirements and can obtain a list of what actions need to be taken at which supplier and by when they must be started, in various scenarios (as desired). Assuming the data is complete (i.e. has all information pertaining to all suppliers), the OEM now has a good vision into what problems may be created in its supply chain in view of its increasing requirements, where they will be created, what actions need be taken to resolve those problems, and by when those actions must be started. The OEM can then focus on those actions with those suppliers and be less concerned with the others. While this approach may not prevent any supply chain issues from occurring, it will lessen the number of them (all other things being equal). 
     Preferably, along with each remedial action possible, a revised supplier capacity contingency ratio for the given period in time is calculated, taking into account the effects of that action. In this way, the cumulative effects of several actions will be known, and, where there are more than one of them, the OEM and the supplier will be able to take this into account when making a decision as to which action to implement (or how to otherwise proceed). 
     It is also preferred to re-compare the revised supplier capacity contingency ratio for each period with the threshold value indicative of an insufficiency in the supplier capacity contingency, to determine any periods still having insufficient supplier capacity contingency. 
     Optionally, for at least one of the periods having an insufficient supplier capacity contingency, a difference between a supplier reference-date maximum capacity and the supplier projected future load for that period can be calculated. This difference is referred to as the “surge capacity” and is shown in  FIG. 1 . The supplier reference-date maximum capacity is the capacity that can be triggered quickly (e.g. within a week) under difficult conditions and can only be sustained for a short period of time (e.g. a few months). In this manner, it may be known whether it would be possible to implement a short term solution to a supply issue that might function until a permanent increase in available capacity can be brought on line. 
     The present invention is not merely the computer implementation of a previously-known method, as the method was not previously known. Moreover, the present invention requires a computer in order to be carried out, given the volume of calculations that are required. It would not be possible to do so by hand. 
     No particular computer (hardware or software) is required. It is within the knowledge and skill of a skilled computer programmer to select appropriate hardware and software and to program and implement a method of the present invention depending on those choices. It is preferred to use a standard PC running the Microsoft™ Windows XP™ operating system and Microsoft Office™. The method is preferably implemented using Microsoft Excel™ and programmed using macros and Visual Basic™. 
     In an additional aspect, the present invention provides a computer-readable information storage device (e.g. a hard drive, a USB-key, computer memory, a network drive, an internet website, etc.) containing computer-executable instructions (e.g. a computer file) to enable a method of the present invention to be executed by a computer. 
     Embodiments of the present invention each have at least one of the above-mentioned objects and/or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present invention that have resulted from attempting to attain the above-mentioned objects may not satisfy these objects and/or may satisfy other objects not specifically recited herein. 
     Additional and/or alternative features, aspects, and advantages of embodiments of the present invention will become apparent from the following description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the present invention, as well as other aspects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, where: 
         FIG. 1  shows graphically the relationship of load, available capacity and capacity contingency; 
         FIG. 2  shows graphically a simplified example of what may happen over time if the OEM load on a particular supplier increases; 
         FIG. 3  shows graphically an example of remedial actions to increase supplier capacity and their lead time for implementation; 
         FIG. 4  is a flow chart illustrating the steps of a preferred embodiment of the present invention; 
         FIGS. 5A-5U  are a print-out of a MS Excel Worksheet showing sample supplier data for the present invention; 
         FIGS. 6A-6H  are a print-out of a MS Excel Worksheet showing sample first-user data for the present invention; 
         FIGS. 7A-7D  are a print-out of a MS Excel Worksheet showing a first sample output of the present invention; 
         FIGS. 8A-8D  are a print-out of a MS Excel Worksheet showing a second sample output of the present invention; and 
         FIGS. 9A-9F  are a print-out of a MS Excel Worksheet showing a third sample output of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 4 , there is shown a flow chart illustrating the various steps of a preferred embodiment of the present invention. In step  110 , data related to the supplier reference-date load for the supplied unit for each of the periods is accessed. In step  120 , data related to the supplier reference-date available capacity for the supplied unit for each of the periods is accessed. These steps are carried out on a personal computer running Microsoft Windows XP™ and Microsoft Excel™ by opening a file containing the requisite data that has been previously prepared in a format that is readable by MS Excel. A sample worksheet from such a file is shown in  FIG. 5 . This worksheet (and thus file) contains both the data of step  100  and the data of step  110  (and thus the steps are carried out simultaneously by the opening of the file). (It should be noted that the data shown in  FIG. 5  is not real-life actual data, it is fictitious data that has been created solely for the purpose of illustration.) MS Excel has been selected given that it is relatively easy to use and is generally accessible to most PC users. 
     Specifically,  FIG. 5  contains data associated with a number of suppliers and supplied units, including optional data not required by the present invention. Most importantly, the data provided includes the name of the supplier and the supplied unit (production line), an indication of the reference date of the data (assessment date), the total reference-date load (current load), a load-split by AIRBUS aircraft program (and in some cases aircraft series), other entity load (other customers load), reference-date available capacity (current available capacity), maximum available capacity (current max capacity), load splits by period (M+2 though M+36), and data related to various remedial actions that can be taken to increase capacity (action, new expected capacity, start date, etc.). 
     In step  130 , data related to an AIRBUS supplied-unit requirement for the supplied unit for each of the periods is accessed. This step is also carried out by opening a file containing the requisite data that has been previously prepared in a format that is readable by MS Excel. A sample worksheet from such a file is shown in  FIG. 6 . (It should be noted that the data shown in  FIG. 6  is not real-life actual data, it is fictitious data that has been created solely for the purpose of illustration). In  FIG. 6 , the data related to the AIRBUS supplied-unit requirement is in the form of the number of aircraft that AIRBUS will manufacture in a given month (a month being the period in the present embodiment) for the months of June 2006 to December 2020. Further, as can also be seen in  FIG. 6 , the data related to the AIRBUS supplied-unit requirement includes data related to (previously described) AIRBUS aircraft programs. For example, the AIRBUS A321 is part of the AIRBUS Single Aisle Program. Thus, for instance, for the month of January 2006, the 0.5 A321 aircraft are included in the 8.0 Single Aisle aircraft that will be produced in that month. 
     As can be seen by examining each of the columns in  FIG. 6 , the quantity of aircraft of each program being produced per month is generally increasing over time. This indicates that the number of parts required from suppliers to produce these aircraft will also increase over time. It will be noted that the increases are not consistent month over month, nor between aircraft programs, nor in between particular aircraft series within a program (and thus would be extremely difficult to mathematically model). 
     Referring back to  FIG. 4 , in step  140 , a supplier future load for the supplied unit for each of the periods is calculated, the supplier future load being based on the supplier reference-date load for that period and the AIRBUS supplied-unit requirement for that period. In step  150 , a supplier capacity contingency for each period, the supplier capacity contingency for each period being defined as a difference between the supplier future load for that period and the supplier reference-date available capacity for that period, is calculated. In step  160 , a supplier capacity contingency ratio for each period is calculated, the supplier capacity contingency ratio for each period being a ratio between the supplier capacity contingency for that period and the supplier reference-date available capacity for that period. In step  170 , the supplier capacity contingency ratio for each period is compared with a threshold value indicative of an insufficiency in the supplier capacity contingency, to determine any periods having insufficient supplier capacity contingency. In the present case there are two such threshold values, 10% and 5%. Each period (for each supplied unit) is assigned a colour based on the comparison of its supplier capacity contingency with the threshold values. Most importantly, ratios less than 5% have been termed “reds” (and are coloured red or black), and indicate periods where there is an insufficient supplier capacity contingency. 
     Still referring to  FIG. 4 , in step  180 , data related to actions that can be undertaken to change the supplier reference-date available capacity for the supplied unit and to a lead time required in order to implement the actions is accessed. In step  190 , at least one action that can be undertaken to change the supplier reference-date available capacity for the supplied unit for a first period in time having insufficient supplier contingency is determined. In step  200 , for the at least one action that can be undertaken to change the supplier reference-date available capacity for the supplied unit for the first period in time having insufficient supplier contingency, a latest action implementation date by which that action must be undertaken in order to change the reference-date available capacity for the supplied unit in time for the first period in time having insufficient supplier contingency based on the lead time for that action is determined. 
     Still referring to  FIG. 4 , in step  210 , a revised supplier capacity contingency ratio for the first period in time having insufficient supplier contingency and for periods thereafter is determined, based on the supplier projected future load, the supplier reference-date available capacity for that period, and the actions that can be undertaken to change the supplier reference-date available capacity for that period. In step  220 , the revised supplier capacity contingency ratio for each period is compared with the threshold value indicative of an insufficiency in the supplier capacity contingency, to determine any periods still having insufficient supplier capacity contingency. In step  230 , for at least one of the periods having an insufficient supplier capacity contingency, a difference between a supplier reference-date maximum capacity and the supplier projected future load for that period is calculated. 
     Finally, still referring to  FIG. 4 , in step  240  data related to the supplier capacity contingency ratio for each period is output. 
     Each of the aforementioned steps are carried out through various operations by appropriate MS Excel macros.  FIG. 7  shows the example of such an output in the form of an MS Excel worksheet. As can be seen in  FIG. 7 , there is a column for the supplier name and the name of the supplier production line (in this embodiment the supplied unit of the present invention). There are also columns for each of the periods in question (the series of periods being 36 months long, starting at August 2008 and extending to July 2011). Each period is assigned a colour based on its comparison with the threshold values. The date a supplied contingency ratio first turns “red” is also provided. Also indicated are the programs (i.e the uses) to which the parts will be put in the columns to the right of the columns for each period. 
       FIG. 8  provides another possible output, again prepared with appropriate MS Excel Macros. Specifically,  FIG. 8  is an output on the basis of a single supplier “Fastener Supplier” in Tarbes, France and is split amongst the various supplied units that this supplier supplies: “Bolt PL 2”, “Screw PL 1”, etc. For each supplied unit, there is a graph showing on a periodic basis the load (the bar) vs. the capacity (the line). Taking Bolt PL 2 as an example, the load exceeds the capacity for most of the periods. Below the graph, there are identified two actions that the supplier may take to increase its capacity, the lead time that the action requires, and based on the lead time, the start date and the end date for the action. Similar information is available for each of the other supplied units supplied by that supplier. 
       FIG. 9  provides yet another output, again prepared with appropriate MS Excel Macros. Specifically,  FIG. 9  is an output on the basis of all of the suppliers supplying units to AIRBUS requiring remedial actions to be taken to increase their supply capacity in view of the fact that their supply capacity contingency ratio is below an acceptable threshold. As can be seen in  FIG. 9 , the action list indicates the supplier name, supplier production line (supplier unit), the remedial action to be taken, the date by which the action must be taken in order to timely increase capacity, and the AIRBUS affected aircraft programs and series. 
     Modifications and improvements to the above-described embodiments of the present invention may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the present invention is therefore intended to be limited solely by the scope of the appended claims.