Abstract:
A method of generating an engineered object is performed using the following steps. A request for proposal defining the engineered object is received. Components of the engineered object are defined. A cost estimate is generated based on at least one of the request for proposal, the components, and engineering rules and knowledge. An engineered product layout is generated based on at least one of the request for proposal and the engineering rules and knowledge. A proposal is generated based on the cost estimate and the engineered product layout. An order is generated based on the proposal. An object design is generated based on the proposal and the order. The engineered object is generated based on the object design.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 12/510,519 filed Jul. 28, 2009. 
         [0002]    U.S. patent application Ser. No. 12/510,519 is a continuation of U.S. Ser. No. 12/070,603 filed Feb. 19, 2008, now U.S. Pat. No. 7,567,849 issued Jul. 28, 2009. 
         [0003]    U.S. patent application Ser. No. 12/070,603 is a continuation of U.S. Ser. No. 11/430,798 filed May 9, 2006, now U.S. Pat. No. 7,333,868 issued Feb. 19, 2008. 
         [0004]    U.S. patent application Ser. No. 11/430,798 claims priority of U.S. Provisional Patent Application No. 60/679,447 filed on May 10, 2005. 
         [0005]    The contents of all related applications listed above are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0006]    The present invention relates to systems and methods of designing and manufacturing engineered objects and, more specifically, to design and manufacturing systems and methods for manufacturing engineered objects based on a customer-approved design. 
       BACKGROUND OF THE INVENTION 
       [0007]    The term “object” is used herein to refer to a mechanical, electrical, or chemical component or any combination of such components. The term “engineered” as used herein refers to an object at least some aspect of which is specifically engineered to suit the requirements of a particular customer. 
         [0008]    The present invention is of particular significance in the context of the design and manufacturing of bulk material handling systems such as the type typically used in a manufacturing environment to carry material from one location to another. The present invention will thus be described herein using the example of a system or method of designing and manufacturing an engineered object taking the form a bulk material handling system. However, the example presented herein is described for illustrative purposes only, and the present invention may take forms than the illustrative example described below. 
         [0009]    A bulk material handling system typically requires the combination of mechanical and electrical components and material properties into an overall system that fits the particular working environment of a specific customer. Although many of the components used in a bulk material handling system are standardized, each particular design requires custom engineering. A bulk material handling system thus meets the definition of an engineered object as set forth above. 
         [0010]    Conventionally, the design and manufacturing of a bulk material handling system involves the services of a salesman and an engineering department. The conventional process of designing and manufacturing a bulk material handling system may be described as follows. 
         [0011]    Initially, the customer sends to the salesman a Request For Quotation (RFQ) containing the requirements of a proposed new bulk material handling system. The salesman works with the engineering department to generate a proposal based on the RFQ. The proposal contains engineering specifications defining the proposed new bulk material handling system and a quote of the price. The proposal typically may take up to several days to generate. The customer places an order when the proposal is accepted. 
         [0012]    After the order is placed, the engineering department generates approval layout drawings based on the approved engineering specifications. The customer confirms that the approval layout drawings are accurate, and, if not, the approval layout drawings may be revised. The approval layout drawings are commonly produced based on finished job drawings for similar bulk material handling systems that have been hand-modified based on the specifications defined by the order. 
         [0013]    Once the approval layout drawings are finalized, the engineering staff will generate detail manufacturing drawings and associated documents. From the detail manufacturing drawings, CNC-ready files are created for the cutting of sheet metal. The sheet metal and other components such as motors or the like are then combined with the sheet metal components based on the detail manufacturing drawings. The finished bulk material handling system is then installed at the customer&#39;s site. 
         [0014]    The Applicant has identified at least the follow problems with conventional systems and methods for designing and manufacturing bulk material handling systems. 
         [0015]    First, the step of generating the proposal requires the involvement of highly experienced engineering staff for at least several hours and often several days. The use of experienced engineering staff is expensive, and the fact that the proposal may take several days to prepare may place the manufacturer at a competitive disadvantage. Second, even with involvement of engineers for many hours, the preliminary specifications, without the approval drawings, do not include the detail drawings required for manufacture. The use of preliminary specifications to create the proposal creates the potential for costly design mistakes and inaccuracies in the quote. Third, the step of generating approval drawings can take several iterations over the period of one to two weeks. Fourth, the step of generating the detail manufacturing drawings based on prior finished job drawings for other projects often resulted in components that did not fit together or match the approval drawings. 
         [0016]    The conventional process of designing and manufacturing a bulk material handling system is thus time consuming, requires significant highly technical labor simply to prepare a proposal, and is susceptible to design errors that are difficult and costly to fix. The need thus exists for improved systems and methods of designing and manufacturing engineered objects such as bulk material handling systems. 
       SUMMARY OF THE INVENTION 
       [0017]    The invention may be embodied as a method of generating an engineered object comprising the following steps. A request for proposal defining the engineered object is received. Components of the engineered object are defined. A cost estimate is generated based on at least one of the request for proposal, the components, and engineering rules and knowledge. An engineered product layout is generated based on at least one of the request for proposal and the engineering rules and knowledge. A proposal is generated based on the cost estimate and the engineered product layout. An order is generated based on the proposal. An object design is generated based on the proposal and the order. The engineered object is generated based on the object design. 
         [0018]    The present invention may also be embodied as a method of producing an engineered object comprising the following steps. Cost estimates are generated at least in part based on a request for proposal defining the engineered object and engineering rules and knowledge. Layout drawings are generated at least in part based on the request for proposal and engineering rules and knowledge. Object designs are generated at least in part based on the request for proposal, engineering rules and knowledge, and an engineering review. A request for proposal defining the engineered object is accepted. The request for proposal is entered to generate a cost estimate. The request for proposal is entered to generate a layout drawing. A proposal is generated based on the cost estimate and the layout drawing. An order is received based on the proposal. Based on the order and the proposal, an assembly specification, a detail specification, and machine control files comprising the object design are generated. The engineered object is produced based on the assembly specification, the detail specification, and the machine control files. 
         [0019]    The present invention may also be embodied as a method of producing a bulk material handling system comprising the following steps. Cost estimates are generated for bulk material handling systems based on requests for proposal. Layout drawings are generated. Object designs are generated at least in part based on at least one of parameters associated with components of bulk material handling systems, engineering rules and knowledge related to bulk material handling systems, and an engineering review. A request for proposal defining a bulk material handling system design is generated. A cost estimate is generated based on the request for proposal. A layout drawing is generated based on the request for proposal. A proposal is generated based on the cost estimate and the layout drawing. An order is received based on the proposal. Based on the order and the proposal, an assembly specification, a detail specification, and machine control files comprising the bulk material handling system design are generated. The bulk material handling system is produced based on the assembly specification, the detail specification, and the machine control files. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is block diagram depicting a system designing and manufacturing an engineered object; 
           [0021]      FIG. 2  is a flow diagram illustrating a method of using the system depicted in  FIG. 1 ; 
           [0022]      FIG. 3  is a flow diagram depicting one of the steps of the method of  FIG. 2  in further detail; 
           [0023]      FIGS. 3A-C  are screen shots depicting software panels that may be generated by the system of  FIG. 1 ; 
           [0024]      FIG. 3D  is an example layout diagram generated by the system of  FIG. 1 ; 
           [0025]      FIG. 4  is a flow diagram depicting one of the steps of the method of  FIG. 2  in further detail; 
           [0026]      FIGS. 4A and 4B  are screen shots depicting software panels that may be generated by the system of  FIG. 1 ; 
           [0027]      FIGS. 4C and 4D  are views of an example three-dimensional model generated by the system of  FIG. 1 ; 
           [0028]      FIGS. 4E and 4F  are two-dimensional drawings generated based on the example three-dimensional model of  FIG. 4C ; 
           [0029]      FIGS. 4G-J  are tables depicting examples of a bill of materials, buy list, ship list, and fabrication list generated by the system of  FIG. 1 ; 
           [0030]      FIG. 4K  is a drawing containing assembly specifications generated by the system of  FIG. 1 ; and 
           [0031]      FIG. 5  is a flow chart depicting the operation of an example parametric design system that may form part of or be used by the system of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    Referring initially to  FIG. 1 , depicted therein is a design and manufacturing system  20  constructed in accordance with, and embodying, the principles of the present invention. The example design and manufacturing system  20  is illustrated in the context of a method of designing and manufacturing of an engineered object  22 , which, in the detailed example that will be described below, takes the form of a bulk material handling system. 
         [0033]    The design and manufacturing system  20  comprises a parametric design system  30 ; the parametric design system  30  comprises an estimate generator  32 , a layout drawing generator  34 , and a design drawing generator  36 . The parametric design system  30  determines the parameters associated with components of an object based on: (a) the parameters associated with other components of the object; and (b) engineering rules and knowledge developed based on experience with objects similar to the engineered object  22 . 
         [0034]    The example system  20  further comprises factory automation machines  40 , manufacturing facilities  42 , and/or off-site assembly facilities  44 . The factory automation machines  40 , manufacturing facilities  42 , and off-site assembly facilities  44  all are or may be conventional and will not be described herein beyond what is necessary for a complete understanding of the present invention. 
         [0035]    Also depicted in  FIG. 1  are system functions that employ human input. In particular, the entity ordering the engineered object  22  is identified as the customer and is indicated by reference character  50 . The human involvement of the entity manufacturing the engineered object  22  is represented as a sales person  52  and an engineer  54 . In addition, the entity manufacturing the engineered object  22  may further employ additional human functions such as purchasing, sales, marketing, accounting, and management, but these functions are only tangentially related to the system  20  and will not be described in detail herein. 
         [0036]    The customer  50 , sales person  52 , and engineer  54  are not per se part of the design and manufacturing system  20  of the present invention but are integral to the design and/or manufacturing of the engineered object  22  using the system  20 . Further, the functions performed by any of the customer  50 , sales person  52 , and/or engineer  54  may be, and typically are, performed by more than one individual. 
         [0037]      FIG. 1  further illustrates that the example engineered object  22  is formed by the assembly of subassemblies  60   a  and  60   b  at the off-site assembly facilities  44 . The subassemblies  60   a  and  60   b  are in turn formed by the assembly of manufactured components  62   a,    62   b,  and  62   c  and procured components  64   a  and  64   b  at the manufacturing facilities  42 . For clarity, the engineered object  22 , subassemblies  60 , manufactured components  62 , and procured components  64  are all depicted in highly schematic forms in  FIG. 1 . 
         [0038]    In the context of a bulk material handling system, the manufactured components  62  are typically two-dimensional sheet metal components cut to be folded into three-dimensional structures; in this context, the procured components  64  are motors, sensors, belts, controllers, and the like that are assembled with the three-dimensional structures formed by the manufactured components  62  into the subassemblies  60  and eventually into the engineered object  22  in the form of a bulk material handling system. 
         [0039]    The entity that manufactures the engineered object  22  may own and operate the parametric design system  30 , the factory automation machines  40 , and the manufacturing facilities  42 . The on-site assembly facilities  44  may be owned and operated by an entity associated with the customer  50 . However, in the context of modern manufacturing practices, it should be clear that the parametric design system  30 , factory automation machines  40 , manufacturing facilities  42 , and on-site assembly facilities  44  may be owned and/or operated by other entities and located at widely distributed physical locations. 
         [0040]    During the operation of the design and manufacturing system  20 , numerous documents are generated. In the context of the present invention, the term “document” broadly refers to all forms of communication such as paper documents and computer files that represent design data associated with the design and manufacture of the engineered object  22 . This design data can take a wide variety of forms, including text, drawings, databases, lists, and computer code. The following table identifies and describes certain documents that are used as part of the design and manufacturing system  20  as described in  FIG. 1 : 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Document Name 
                 Ref. No. 
                 Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 RFQ (Request for 
                 70 
                 Generally - describes the performance 
               
               
                 Quotation) 
                   
                 requirements of the engineered object. 
               
               
                   
                   
                 Bulk Material Handling - describes 
               
               
                   
                   
                 properties of the proposed bulk material 
               
               
                   
                   
                 handling system such as the type of 
               
               
                   
                   
                 material to be carried and its properties, 
               
               
                   
                   
                 the amount to be carried per unit time, 
               
               
                   
                   
                 and locations where material feeds into 
               
               
                   
                   
                 the machine and is discharged from the 
               
               
                   
                   
                 machine. 
               
               
                 Cost Estimate 
                 72 
                 Generally - summarizes the cost to 
               
               
                   
                   
                 manufacture the engineered object. 
               
               
                   
                   
                 Bulk Material Handling - summarizes the 
               
               
                   
                   
                 cost to manufacture the proposed bulk 
               
               
                   
                   
                 material handling system. 
               
               
                 Layout 
                 74 
                 Generally - approval drawings, 
               
               
                 Specifications 
                   
                 specifications, and the like of the 
               
               
                   
                   
                 engineered object. 
               
               
                   
                   
                 Bulk Material Handling - approval 
               
               
                   
                   
                 drawings, specifications, and the like 
               
               
                   
                   
                 describing the basic parameters of the 
               
               
                   
                   
                 proposed bulk material handling system. 
               
               
                 Proposal 
                 76 
                 Generally - the combination of approval 
               
               
                   
                   
                 drawings and cost estimate related to an 
               
               
                   
                   
                 engineered object. 
               
               
                   
                   
                 Bulk Material Handling - the combination 
               
               
                   
                   
                 of approval drawings and cost estimate 
               
               
                   
                   
                 related to a proposed bulk material 
               
               
                   
                   
                 handling system. 
               
               
                 Order 
                 78 
                 Generally - agreement by customer to 
               
               
                   
                   
                 purchase an engineered object as 
               
               
                   
                   
                 described in a proposal. 
               
               
                   
                   
                 Bulk Material Handling - agreement by 
               
               
                   
                   
                 customer to purchase a bulk material 
               
               
                   
                   
                 handling system as described in a 
               
               
                   
                   
                 proposal. 
               
               
                 Detail 
                 80 
                 Generally - bill of materials and 
               
               
                 Specifications 
                   
                 assembly drawings describing the 
               
               
                   
                   
                 manufactured and procured components 
               
               
                   
                   
                 of a particular engineered object and how 
               
               
                   
                   
                 these components are assembled to 
               
               
                   
                   
                 obtain subassemblies of a particular 
               
               
                   
                   
                 engineered object. 
               
               
                   
                   
                 Bulk Material Handling - bill of materials 
               
               
                   
                   
                 and assembly drawings describing the 
               
               
                   
                   
                 procured components and two- 
               
               
                   
                   
                 dimensional sheet metal components of 
               
               
                   
                   
                 a bulk material handling system and how 
               
               
                   
                   
                 these components are assembled to 
               
               
                   
                   
                 obtain subassemblies of a particular bulk 
               
               
                   
                   
                 material handling system. 
               
               
                 Machine Control 
                 82 
                 Generally - computer files for controlling 
               
               
                 Files 
                   
                 factory automation machines to 
               
               
                   
                   
                 manufacture custom components of a 
               
               
                   
                   
                 particular engineered object. 
               
               
                   
                   
                 Bulk Material Handling - flat pattern files 
               
               
                   
                   
                 for controlling CNC machines to form 
               
               
                   
                   
                 two-dimensional components from sheet 
               
               
                   
                   
                 metal that will eventually be formed into 
               
               
                   
                   
                 three-dimensional structures. 
               
               
                 Assembly 
                 84 
                 Generally - assembly instructions for 
               
               
                 Specifications 
                   
                 final assembly of subassemblies to 
               
               
                   
                   
                 obtain a particular engineered object. 
               
               
                   
                   
                 Bulk Material Handling - assembly 
               
               
                   
                   
                 instructions for final assembly of 
               
               
                   
                   
                 subassemblies to obtain a particular bulk 
               
               
                   
                   
                 material handling system. 
               
               
                   
               
             
          
         
       
     
         [0041]    Referring now to  FIG. 2 , depicted at  120  therein is a method of using the example design and manufacturing system  20 . The method  120  starts with the customer  50  providing an RFQ  70  to the sales person  52 . Using the performance requirements described in the RFQ  70 , at step  130  the sales person  52  uses the estimate generator  32  and layout drawing generator  34  to generate an initial cost estimate document  72   a  and an initial approval specification drawing  74   a.  The sales person  52  then generates an initial proposal  76   a  at step  130  and presents this proposal  76   a  to the customer  50  for acceptance at step  134 . 
         [0042]    In some situations, the customer  50  may accept the initial proposal  76   a . In many situations, the customer  50  may reject the initial proposal  76   a  at step  134  for any one of a number of reasons such as the cost estimate  72   a  exceeding the budget, location or clearance problems, and/or a change of performance requirements since the generation of the original RFQ  70 . In any of these situations, the process may return to step  130 , and the sales person  52  may generate subsequent cost estimates  72   b  and possibly  72   c  and approval specifications  74   b  and possibly  74   c.  Based on these subsequent cost estimates  72   b,    72   c  and approval specifications  74   b,    74   c,  the sales person  52  may repeat step  132  to generate additional proposals  76   b  and possibly  76   c  until one of the proposals  76  is accepted at step  134 . 
         [0043]    When the customer  50  accepts one of the proposals  76  at step  134 , the customer  50  generates an order  78  at step  140 . The order  78 , which contains or identifies the approval specifications  74  defining the engineered object  22 , is forwarded to the engineer  54 . As shown at step  142 , the engineer  54  uses the design specifications generator  36  to generate the Detail Specifications, the machine control files  82 , and the assembly specifications  84 . 
         [0044]    The machine control files  82  are sent to the factory automation machines  40  to control these machines  40  to manufacture the manufactured components  62  at step  150 . The Detail Specifications  82  are used to identify and procure the procured components  64  at step  152 . Using the Detail Specifications  80 , the manufactured components  62  and the procured components  64  are combined to form the subassemblies  60  using the manufacturing facilities  42  at step  160 . 
         [0045]    In the example shown in  FIG. 1 , the manufactured components  62   a  and  62   b  and procured component  64   a  are combined to form the subassembly  60   a , while the manufactured component  62   c  and the procured component  64   b  are combined to form the subassembly  60   b.  Typically, the subassemblies  60   a  and  60   b  are then shipped to the off-site assembly facilities  44  where they are assembled using the assembly specifications  84  at step  160  to form the engineered object  22 . 
         [0046]    With the foregoing general understanding of the principles of the present invention in mind, the details of construction and operation of the example design and manufacturing system  20  will now be described in detail. 
         [0047]    Referring now to FIGS.  3  and  3 A-D of the drawing and Exhibits A and B attached hereto, the step  130  of the method  120  of using the example design and manufacturing system  20  will now be described in further detail. At an initial step  210 , the sales person  52  uses the parametric design system  30  to create a new proposal using the software panel depicted in  FIG. 3A . As shown in  FIG. 3A , the sales person  52  enters data identifying the customer  50  and data, such as a proposal number, project reference name, and the like, of a proposal associated with a particular proposed bulk material handling system. 
         [0048]    At step  212 , the sales person  52  defines the properties of the proposed bulk material handling system using a software panel as shown in  FIG. 3B . The properties entered into the parametric design system  30  at step  212  numerically define the controlling parameters associated with bulk material handling systems. These controlling parameters include material to be conveyed, capacity, length, width, incline, construction materials, and available options. 
         [0049]    Based on the properties entered at step  212 , at step  214  the machine specifications are generated.  FIG. 3C  depicts a software panel summarizing the machine specifications for the properties entered in the software panel illustrated in  FIG. 3B . 
         [0050]    Based on the machine specifications, the parametric design system  30  generates the cost estimate  72  at step  220  and the layout specifications  74  at step  222 . The cost estimate  72  is schematically depicted in  FIG. 3 , but a sample print-out of the cost estimate associated with the machine specifications generated at step  214  is attached hereto as Exhibit A. The cost estimate  220  typically contains unit, line item, and total cost values, but these cost values are not per se relevant to the present invention and have been omitted from the sample cost estimate contained in Exhibit A. The cost estimate  72  is typically not directly disclosed to the customer  50  but is used by the sales person  52  to generate the proposal  76  as will be described in further detail below. 
         [0051]    The parametric design system  30  further generates at step  222  the layout specifications  74  based on the machine specifications generated at step  214 . The layout specifications  74  typically include a summary of the more important specifications and a layout drawing associated with the proposed bulk material handling system. A sample layout drawing is illustrated in  FIG. 3D  of the drawing. The layout specifications  74  are typically included in the proposal  76  along with a price based on the cost estimate  72 . 
         [0052]    In particular, a sample proposal is attached hereto as Exhibit B. The proposal in Exhibit B takes the form of a multiple-page word processing document that has been automatically generated based on information entered into and generated by the parametric design system  30 . The sample proposal attached hereto contains on pages 1 and 2 boilerplate legal language associated with terms of sale, shipment obligations, freight options, and the like. Page 3 contains a summary of the important specifications and layout drawing of the proposed bulk material handling system generated from the layout specifications  74  and a price generated from the cost estimate  72 . Page 4 contains even more detailed specifications and price of the drive component of the proposed bulk material handling system. 
         [0053]    Based on a proposal such as the sample proposal in Exhibit B, the customer determines whether the proposed new bulk material handling system and price as defined in the proposal are acceptable. If not, the sales person can easily and quickly generate additional proposals  76 . 
         [0054]    When a proposal  76  is ultimately accepted, the customer  50  generates the order  78 . The order  78  obligates the customer  50  to purchase the proposed new bulk material handling system at the agreed upon price and obligates the sales entity to manufacture the new proposed bulk material handling system according to the specifications of the proposal  76 . The order  78  may contain or refer to the accepted proposal  76 . 
         [0055]    The order  78  is passed to the engineer  54 . The engineer  54  performs the step  142  of the method  120  using the example design and manufacturing system  20 , and this step  142  will now be described in further detail with reference to FIGS.  4  and  4 A-J. 
         [0056]    As discussed above, the layout specifications  74  define basic, important characteristics of the proposed new bulk material handling system, especially those relating to price. However, the layout specifications  74  do not define the details of construction and assembly of the proposed new bulk material handling system. As generally described above, at step  142  the engineer  54  uses the parametric design system  30  to generate the detailed specifications  80 , machine control files  82 , and assembly specifications  84 . 
         [0057]    Initially, in a step  250  shown in  FIG. 4 , the engineer  54  defines the subassemblies identified in the layout specifications  74 . As an example, in  FIG. 4A  the engineer  54  has identified the tail subassembly of the bulk material handling system identified in the layout specifications  74 . 
         [0058]      FIG. 4B  illustrates a software panel that allows the engineer  54  to size the individual components of the tail subassembly. The panel of  FIG. 4B  starts with default numerical values but informs the engineer  54  of alternative numerical values available for each of the individual components. The engineer  54  thus uses personal knowledge, training, and experience to confirm the values associated with the tail subassembly under design. These values are generated by the parametric design system  30  based on the engineering rules embodied therein and the engineering specifications defined in the order  78 . 
         [0059]    When the values associated with the components of the tail subassembly are confirmed, the engineer  54  next directs the parametric design system  30  to generate component values associated with the tail subassembly design. In particular, the parametric design system  30  generates the component values based on the accumulated knowledge embodied in the engineering rules stored in the parametric design system  30  as will be described in further detail below. 
         [0060]    The component values are then passed to a three-dimensional modeling system such as Solid Works. The three-dimensional modeling system generates a three-dimensional computer model representing the tail subassembly at step  254 , and a sample two-dimensional view of the three-dimensional model of the tail subassembly is depicted in  FIG. 4C . 
         [0061]    The three-dimensional modeling system allows the tail assembly to be rendered in many different views and perspectives. The engineer  54  analyzes the three-dimensional model from different views and perspectives to determine, at step  256 , whether a problem exists with the design of the tail subassembly. 
         [0062]      FIG. 4D  is a view of the sample tail subassembly depicted in  FIG. 4C  illustrating misaligned holes  258   a  and  258   b.  The misalignment depicted in  FIG. 4D  is typically the result of an error in the engineering rules governing the relationships among components forming the subassembly. 
         [0063]    Accordingly, if the engineer  54  determines at step  256  that a problem exists with the tail subassembly, the process proceeds to step  260  where the engineer revises rules contained in the engineering rules database of the parametric design system  30 . After the rules have been properly revised, the method returns to step  254  where another three-dimensional model is generated based on the values selected or confirmed in step  252 . 
         [0064]    When the engineer  54  determines at step  256  that the three-dimensional model does not contain any problems, the parametric design system  30  passes values associated with the designed tail subassembly to a Computer Aided Drafting (CAD) program such as AutoCAD. As shown in  FIG. 4E , at step  270  AutoCAD generates two-dimensional drawings based on the three-dimensional model that depict the tail subassembly, the components thereof, and instructions describing how to combine the components to form the subassembly. The two-dimensional drawings generated at step  270  form part of the detail specifications  80 . 
         [0065]    The parametric design system  30  further generates at step  270  a bill of materials such as depicted in  FIG. 4G  and associated documents for ordering procured parts such as a buy list, an example of which is shown in  FIG. 4H , and a ship list, an example of which is shown in  FIG. 4I . The example parametric design system  30  also generates at step  270  a fabrication list used during the factory pre-assembly step  160  described above. 
         [0066]    As shown at step  272 , AutoCAD generates flat pattern drawings as depicted in  FIG. 4J  defining how the manufactured parts are to be cut. AutoCAD further generates the motion control files  82  corresponding to the flat patterns. 
         [0067]    Step  274  illustrates that the parametric design system  30  generates the assembly specifications  84 , a sample of which is depicted at  FIG. 4K  of the drawing. 
         [0068]    The fundamental principles of a parametric design system such as the parametric design system  30  used by the design and manufacturing system  20  are generally known and will not be described herein beyond what is required for a complete understanding of the present invention. 
         [0069]      FIG. 5  illustrates an example parametric design system that may be used as the parametric design system  30  described above. Initially, the controlling parameters associated with a type of engineered object to be produced are defined at step  320 . Next, an engineering rules database  322  is created at step  322 . The engineering rules database  322  contains rules defining the components associated with a given type of engineered object and the relationships among these components. The engineering rules database  322  of the example parametric design system  30  further contains cost information associated with these components. 
         [0070]    At step  324 , the user enters sizing information defining a particular engineered object to be designed. Based on the engineering rules database created at step  322  and the sizing data entered at step  324 , at step  326  a machine specification  328  is generated. 
         [0071]    The machine specification  328  can take many different forms. In the context of the example parametric design system  30 , the machine specification may take the form of cost estimate  72 , the approval specifications  74 , the design specifications  80 , and/or the assembly specifications  82 . 
         [0072]    From the foregoing, it should be apparent that the present invention may be embodied in forms other than those described and depicted herein with departing from the scope of the present invention. The scope of the present invention should thus be determined based on the claims attached hereto and not the foregoing detailed description of the invention.