1、This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2011 by Navistar, Inc. APRIL 2011 Page 1 of 5 NAVISTAR, INC. Engineering Design Standards NUMBER: EDS-A16
2、 TITLE: Key Control Characteristics (KCC) CURRENT ISSUE DATE: April 2011 WRITTEN/REVIEWED BY: J. Dewayne Dimit/Esther F. Rice APPROVED BY: Corporate Standards Committee SUPERSEDES ISSUE OF: October 2003 PRINTED COPIES OF THIS DOCUMENT MUST BE VERIFIED FOR CURRENT REVISION Change Notice: Added Key Pr
3、oduct Characteristic (KPC). Added definitions of acronyms. Replaced International Truck and Engine Corporation with Navistar, Inc. per corporate directive. Added paragraphs on identification of key product characteristics and the supporting key control characteristics. 1.0 INTRODUCTION This standard
4、 establishes that Key Control Characteristics (KCC) are the vehicle by which the Engineering community may identify, on part prints or installations, features that must be managed by Statistical Process Control (SPC). 2.0 DEFINITIONS KCC Key Control Characteristic - A process parameter for which var
5、iation must be controlled around a target value to ensure that variation of a KPC is minimized or maintained around its target value. KPC Key Product Characteristic - Reasonably anticipated variation of a Key Product Characteristic could significantly affect a products safety/compliance or is likely
6、 to significantly affect a products fit/function, or safety/compliance. SPC Statistical Process Control FMEA - Failure Modes and Effects Analysis TMS - Truck Material Specification 3.0 APPLICATION The application of KCC should be limited to the vital few characteristics (5% of total characteristics
7、maximum) of the part print or installation diagram. Releases of drawings that specify KCC type control on more than 5% of the characteristics must be approved by the appropriate Chief Engineer in a letter that accompanies the Release Letter. All newly released part prints may be required to indicate
8、 at least one (1) KCC per part. The selection of the characteristics should be derived from SPC, FMEA field history, or design objective. The identification of the characteristics for KCC management must be reviewed with a manufacturing representative or supplier (if they are known) as part of the d
9、esign process. Low volume parts do not warrant the application of SPC and thus should have no KCC applied to the drawing. If a dimension on a low-volume part is critical to its installation, then application of 100% inspection techniques should be considered. 4.0 IDENTIFYING KEY PRODUCT CHARACTERIST
10、ICS A cross functional team is established consisting of (but not limited to) the following: Product Engineering (leader), Manufacturing Engineering, Quality Engineering, Customer Engineering, Manufacturing, Suppliers, Supplier Management & Development, etc. NUMBER: TITLE: CURRENT ISSUE DATE: EDS-A1
11、6 Key Control Characteristics (KCC) April 2011 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2011 by Navistar, Inc. APRIL 2011 Page 2 of 5 The followin
12、g tools are used during the review and Key Product Characteristic identification process: Past test data Past part quality history QFD Team input/consensus Product Benchmarking Product evaluation experience Blueprints and standards Design of experiments PFMEA (Potential Failure Mode and Effects Anal
13、ysis) Process capability information The following criteria should be used in KPC selection. A. A KPC is a product characteristic for which reasonably anticipated variation could significantly affect a products safety/compliance, or is likely to significantly affect customer satisfaction with the pr
14、oduct. And/or B. A KPC is a characteristic that is particularly significant to the part performing its function and warrants additional control and/or capability studies and on-going control because the effects of manufacturing variations are significant. And/or C. A KPC is a characteristic in which
15、 reduction of variation around a target value is likely to improve quality, increase customer satisfaction and/or reduce cost. And/or D. A KPC is a characteristic traceable back to design/performance requirements. The following guidelines apply in identifying KPCs: o A product characteristic should
16、not be designated a KPC to ensure the part is made to print, since all parts must meet print specifications. o A KPC may be a variable or an attribute characteristic. Attribute characteristics could be go/no go, part/feature presence, etc. o KPCs should be identified such that they add to the total
17、quality of the component and increase customer satisfaction. o Over application of KPCs should be avoided since one of the goals of the Key Characteristic Designation System is to aid in the economical manufacture of quality parts. o The team approach should be use for the proper identification of K
18、PCs. There should be a team consensus to make a characteristic a KPC. Consideration for manufacturing concerns should be given during the review whenever possible. o Customer indicated critical characteristics shall not be revised without customer concurrence. Whenever possible, the customer should
19、be part of the cross NUMBER: TITLE: CURRENT ISSUE DATE: EDS-A16 Key Control Characteristics (KCC) April 2011 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liabili
20、ty. 2011 by Navistar, Inc. APRIL 2011 Page 3 of 5 functional review of the requirements. Special customer requirements for the control of these items should be covered in the control plan. o Suppliers should be invited to participate in the team review whenever possible. o Variable characteristics s
21、hould be chosen over attribute characteristics. If an attribute characteristic is chosen, the method of control should be evaluated carefully and the capability defined. Error proofing should be considered where practical. o KPCs may change over time as a result of product or process changes, or tes
22、ts that may establish that the chosen KPC may not have been correct. o Standard or common KPC selection should be considered on similar parts or assemblies, particularly on parts produced by similar processes or utilize shared features. The role of the team is to review the product specifications an
23、d requirements and identify the Key Product Characteristics. Product Engineering should conduct a review prior to reviewing with the cross functional team to develop a list of potential or candidate Key Product Characteristics. 5.0 IDENTIFYING KEY CONTROL CHARACTERISTICS After KPCs are identified, t
24、he lead role of the Key Characteristic Designation System process is taken over by Manufacturing Engineering and Quality Engineering. Key Control Characteristics are identified and documentation requirements for the control plan and reaction plan are generated. A cross functional review is used in d
25、etermining KPCs. As with KPCs, KCCs have certain tests to help determine if a control characteristic is a KCC or not: The following tests should be used in consideration of a characteristic as a KCC. A. A KCC is a process parameter in which variation must be controlled around a target value to ensur
26、e that variation of a KPC is maintained around its target value. The KCC is used to adjust the KPC to its target value. And/or B. A KCC is a process parameter for which variation reduction will reduce variation of a KPC. And/or C. It is directly traceable to a KPC. (examples - KPC - final PD size, K
27、CC - green PD size) And/or D. It is particularly significant to assuring a KPC achieves its target value. The following guidelines apply in identifying KCCs: A KCC can be either a variable or attribute process parameter. KCCs and other process parameters are (generally) not shown on any final produc
28、t documentation or blueprint. KCCs shall be shown on: NUMBER: TITLE: CURRENT ISSUE DATE: EDS-A16 Key Control Characteristics (KCC) April 2011 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate - Control plans - Process sheets - Reac
29、tion plans - In-Process drawings - Operator instructions - Relevant Inspection instructions - Operation and tool sheets KCCs are related to KPC, KCCs should not be specified for standard product characteristics. The following tools should also be considered in determining KCCs: List of KPCs Heat tre
30、at studies PFMEA (Potential Failure Mode and Effects Analysis) Tool and operation sheets Process Flow diagram Failure root cause analysis Control Plan Cause and Effect (Fish Bone) Diagrams QFD Design of Experiments FMA (Failure Mode Analysis) Team input Process capability information In cases where
31、the part or product being designed is a member of a family of parts having similar features, KCC requirements may be assigned to the family of parts by means of a general product specification such as the TMS (Truck Material Specification). When processing revisions to any previously released produc
32、tion part drawings, application of KCC type controls is not mandatory, but should be considered. If KCC application to a drawing is decided upon, the following guideline shall be adhered to: 5.1 KCC Selection Guide: Evaluate each tolerance, and determine if the part would be usable if the process ca
33、pability (Cpk) was as low as 0.5 out of tolerance by a factor of 2. If not, this characteristic is a prime candidate for KCC control. 6.0 SYMBOLIZATION The KCC symbol ( ) and KCC definition block stamps should be utilized as shown in Figure I on page 5. These stamps are available in the Engineering
34、Design Stamp Libraries. KCC6.1 For families of parts, the KCC symbol may be used with a note indicating compliance with the KCC requirement of the general product specification (CEMS, TMS, etc.) for that family of parts. Technical Standards. Suppliers are required to assume all patent liability. 201
35、1 by Navistar, Inc. APRIL 2011 Page 4 of 5 UMBER: EDS-A16 TITLE: Key Control Characteristics (KCC) CURRENT ISSUE DATE: April 2011 NThis document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Figure 1 If the part is one of a family of parts whose KCC control is specified in that parts general specifications, a note and stamp should be added to the drawing directing users to that specification. Example: Technical Standards. Suppliers are required to assume all patent liability. 2011 by Navistar, Inc. APRIL 2011 Page 5 of 5
