XX汽车供应商六西格玛教材

CONTINUOUS IMPROVEMENT GP-8

 PURPOSE: GP-8 defines the supplier's responsibility to have an on-going process for continuously improving the product by improving manufacturing processes to reduce variation and to insure the process has capability and stability over time. It outlines the customer expectations for the suppliers after a part has satisfactorily completed Production Part Approval Process (PPAP) and Early Production Containment (GP-12). (See page 8.)

1.0 SCOPE - The GP-8 procedural criteria applies to all General Motors suppliers, including General Motors allied and affiliated manufacturing operations, and is applicable for all parts and materials even when the customer has not requested data to be provided.

2.0 BASIC QUALITY REQUIREMENTS - All suppliers are required to have in place quality systems that insure parts shipped to the customer meet specification. Further they are expected to have an action plan and the necessary controls to maintain and improve the process capability of designated key product characteristics (KPC's).

2.1 BASIC QUALITY MEASURES - In evaluating their effectiveness in meeting the basic requirements of GP-8, the supplier should monitor the following measures:

A. Voice of the customer. These measures reflect quality performance as seen by the customer.

• Defective parts shipped to the customer.

This measure represents the number of non-conforming parts found at the customer's location, and is expressed in parts per million (PPM).

• Compliance with GP-5. Problem Reporting and Resolution (PR/Rs) are issued by the customers for problems in connection with a supplier's quality, packaging and delivery performance. Specifically measured are timely response and the elimination of repeated nonconformance.

B. Voice of the process. These measurements reflect quality performance as seen by the supplier at the suppliers' facility.

Long term process performance on KPC's. Variation on key product characteristics reflects the variation in the process and is a result of a supplier's ability to control the input variables of a process. Long term process performance is measured as a Ppk value.*

(Note: See Chrysler, Ford and G.M. Production Part Approval Process Manual, for discussion on initial approval requirements, and ongoing minimum requirements.)

• First Time Quality is a measure of a process' ability to make quality parts without scrap or rework. Whenever a supplier's process causes scrap or requires parts to be reworked there is undesirable variation in the input variables. Reducing and controlling the variation in the input variables presents an opportunity for continuous improvement.

N= number of parts started in the process

S = number of parts scrapped

R= number of parts to be reworked/repaired

CONTINUOUS IMPROVEMENT GP-8

3.0 CUSTOMER EXPECTATIONS FOR THE SUPPLIERS' CONTINUOUS IMPROVEMENT PROCESS -- Upon successfully meeting the criteria for exiting Early Production Containment (GP-12), the supplier is responsible to have a quality system that continues to produce material over the long term that meets specifications. All suppliers are expected to measure their quality performance and work for continuous improvement on all parts. The process is to have the support and involvement of the suppliers' top leadership.

3.1 GOAL OF CONTINUOUS IMPROVEMENT -- The goal of the continuous improvement process is to reduce variation in the manufacturing process and to improve the quality of the parts produced.

 * See the Chrysler, Ford, GM Fundamental SPC Reference Manual pages 80-81 for further information.

 3.2 IDENTIFYING PROCESSES FOR CONTINUOUS IMPROVEMENT -- Suppliers should concentrate their efforts on reduction of process variation by listening to the voice of the process and the voice of the customer.

In analyzing first time quality data, the part of the process that creates scrap or when parts require rework is the point in a process needing variation reduction.

In monitoring KPCs, special and common causes of variation are identified as candidates for variation reduction.

PR/Rs from the customer and an analysis of parts rejected by the customer (PPM) also can lead to the discovery of process variation that needs to be reduced.

3.3 ACTIVITIES TO IMPLEMENT CONTINUOUS IMPROVEMENT -- Suppliers should have an organized approach to IDENTIFYING the manufacturing processes that need to receive variation reduction efforts.

For those processes identified, individuals and/or quality improvement work groups should be assigned to analyze the cause of process variation and devise and implement change for improvement.

The work groups should be knowledgeable in problem solving techniques and should incorporate:

Error Proofing Techniques: to prevent or warn of defects.

Design of Experiments: to identify which of the process' input variables, or combinations of input variables, cause the undesirable output variable in the product.

Suppliers should have a follow-up mechanism to insure items for improvement are implemented and verified.

4.0 VERIFICATION OF A SUPPLIERS' CONTINUOUS IMPROVEMENT PROCESS BY THE CUSTOMER -- It is expected that the supplier will maintain documentation supporting the continuous improvement activities conducted in their facilities. The customer may, at their option, review a supplier's continuous improvement efforts periodically.

4.1 VERIFICATION FORMAT --  When the customer notifies the supplier that a verification meeting is to be conducted, the supplier will prepare his documentation showing improvement trends over time and explaining activities to support the continuous improvement effort.

Further, the supplier will complete the "Supplier Continuous Improvement Status Report" (see attached sample and blank form). The purpose of the "Supplier Continuous Improvement Status Report" is to summarize, using a common format, the current status of the suppliers' parts and processes.

CONTINUOUS IMPROVEMENT GP-8

Supplier Continuous Improvement Status Report

• INSTRUCTIONS FOR COMPLETION -

1. Supplier company name complete.

2. Z Code is the shipping code assigned by General Motors. If other supplier numbering systems are used, place the number in this area.

3. This is the number assigned by Dun and Bradstreet to your location. If a CISCO number has been assigned to your location, use the CISCO number.

4. This is the General Motors location where your parts are shipped.

5. This is the date the status report was completed.

6. This number is used for reference to the detailed data on the back of the form.

7. The part number for the part to be included in the report.  Where families of parts have been agreed upon all parts in the family must be included.

Note: If a part number changes due to an engineering change, list the new number and reference the former part number in thc         "Comments" column.

8. The part description must agree with the part nomenclature on the part print.

        Note: Use this column to show when family parts are involved including less finished numbers where appropriate.

9. Model Year is the model year the part is introduced.

10. This is the date that the part received PPAP approval from the customer.

11. The parts per million (PPM) is calculated as the number of non-conforming units divided by the number of units shipped for the reported period. This number is multiplied by one million to get the PPM value.

12. This column should show the number of PR/R's issued against the part number or family of parts.  Any PR/R's issued against a part will be reviewed to insure that GP-5 has been followed and at timely responses have been given and problems haven't reoccurred.

1. Number issued.
2. Number of initial responses on-time.
3. Number of final responses on-time.

13. Key Product Characteristics Summary:

1. The total number of KPC's assigned at the particular part number is to be numbered in this column.
2. Of the total number of KPC's, those that are for attribute characteristics are to be entered in this column.
3. When your control charts for attribute characteristics (p, c, np, u charts) show a value grater than (0) zero, enter the total of these characteristics in this column.
4. Variable characteristics that have a Ppk value less than 1.00 are to be counted in this column.
5. Variable characteristics that have a Ppk value greater than or equal to 1.00 and less than 1.33 are to be counted in this column.
6. Variable characteristics that have a Ppk value greater than or equal to 1.33 are to be counted in this column.
7. Variable characteristics that have a Ppk value greater than or equal to 1.67 are to be counted in this column.

CONTINUOUS IMPROVEMENT GP-8

13. First Time Quality is the percent of parts which enter the process that are produced without scrap, reoperation or rework.

N = number of parts started in the process.

S = number of parts scrapped.

R = number of parts to be reworked/repaired.

Note: First Time Quality is not necessarily a continuous measure. The FTQ measure is developed and analyzed to identify sources of variation within the process.  Later, the FTQ measure is again developed to evaluate the effectiveness of the continuous improvement efforts.

14. Comments to include information concerning:

• actions to get a KPC in control and/or stable.
• actions to contain non-conforming parts that were shipped to the customer.
• changes in part numbers due to an engineering change.
• any other appropriate information.

      Note: If additional space is needed attach another sheet of paper and note it in the "comments" column.

• KEY PRODUCT CHARACTERISICS DETAIL -

13. This number is used for reference to the detailed data on the front of the form.

14. The part number is to correspond to the part number on the front page.

13. a.    Up to 12 KPC's per part can be listed.  If there are more than 12 KPC's on a part use additional lines.          (Corresponding lines on the front page should be skipped).

2. PR is the performance ratio for variable data and is calculated as

Note:  For attribute characteristics enter the percent non-conforming number in this column.

2. Ppk is the performance index for variable data and it is calculated as the minimum of

Note:  For attribute characteristics enter the % sign in this column.

Note:  It is recognized that other established measures are appropriate in certain situations (i.e. individual and moving range, one sided tolerances, etc.).  In such cases the supplier and the customer will determine the most appropriate means of reporting the data.

CONTINUOUS IMPROVEMENT GP-8

• RULES FOR COLLECTING DATA AND CALCULATING PR AND Ppk -

• All submissions must include a minimum of 100 pieces with a minimum of 20 sub groups.

• Data is to be collected so that variable charts include common sources of variation.  i.e. shift change, material change, etc..

• Although special causes of variation are not to be included in the calculation of PR and Ppk they are to be identified on the control charts along with a notation of the corrective action taken.

• When calculating PR and Ppk for a given set of data,                                and Cpk=the minimum of     

        calculation for Cpk is very close to the minimum required values (i.e. 1.01) Ppk = the