Understanding the “Core Tools” of Quality

1. Understanding the “Core Tools” of Quality

2. What are the “core tools”? • The core tools are five reference manuals which supplement the requirements of ISO/TS 16949. These five manuals were developed by the AIAG and are: • PPAP • FMEA • MSA • SPC • APQP

3. Core tool - FMEA Failure Mode Effects and Analysis

4. What is an FMEA and what is the intent? FMEA is an acronym for Potential Failure Mode Effects and Analysis. An FMEA is a systematic group of activities intended to do three things. a.) Recognize and evaluate the potential failure of a product or process and the effects of that failure b.) Identify actions that could eliminate or reduce the chance of the potential failure occurring c.) Document the entire process

5. An FMEA can be used for either a manufacturing process or the design of a product. One of the most important factors to the successful implementation of an FMEA is its timeliness. An FMEA is best done as part of “up front” planning, even though it needs to be a “living document” once the part goes into production. Time spent up front when a process or product is early in the development stage can lead to changes which can be made much more easily than when the product is closer to launch. The main idea behind an FMEA is to anticipate what can go wrong ahead of time and take actions ahead of time.

6. When is an FMEA developed? An FMEA can be developed in three cases: a.) There is a new design, new technology or new process b.) There is a significant modification to to an existing product or process c.) An existing product or process is to be used in a new environment, location or application

7. Who prepares FMEA’s? While FMEA’s are typically the responsibility of an engineer involved with a launch, it needs to be a group effort of people with a broad base of knowledge. This may include people from different areas of the company such as maintenance, quality, manufacturing, paint, etc.

9. “An FMEA is only as good as its follow-up actions.” One of the outputs of an FMEA is the desired follow-up actions. The need for taking effective preventive/corrective actions cannot be overemphasized. An FMEA will be of limited value without positive and effective preventive/corrective actions. The responsible engineer is in charge of ensuring all the recommended actions are implemented.

10. Once a product is launched, is the FMEA “complete”? • While the FMEA is a powerful tool as part of APQP, it needs to be a living document. This means is needs to be updated when: • Recommended actions are completed • There are engineering changes to the part • There are corrective actions once the part is in production • The manufacturing process changes

11. In a plant, you will generally see Process FMEAs, a.k.a. PFMEAs • The PFMEA serves many purposes: • Identifies the process functions and requirements • Identifies potential product and process-related failures modes • Assesses the effects of the potential failures on the customer • Creates a focus on which aspects of the process need increased levels of detection or prevention • Identifies process variables on which to focus controls • Develops a ranked list of potential failure modes, thus establishing a priority system for corrective/preventive actions

12. How is a PFMEA developed?

13. These are the “nuts and bolts” in the development of a PFMEA • For every general process, a list of ways in which that process can fail (failure modes) to meet requirements is developed. • General processes may be: • Sonic welding • Molding • Shipping • Assembly

14. Specific failure modes can be: • Part not fully welded together • Omega clip missing from the assembled part • Dirt in paint • Mixed parts in the tote • Shy grease on the spring • Excessive flash on the parting line • Mounting hole out of dimension

15. The effects of each failure mode is then determined. Examples of the effects can be: • Handle squeaks • Handle binds • Customer unable to mount part to vehicle • Bottle leaks • Part appearance unacceptable to customer

16. The causes of each failure mode are then listed. These causes may be things such as: • Operator instruction not followed • Improper molding parameters • Proper materials not available to operator • Parts contaminated • Poor mold maintenance

17. The current process controls to prevent each failure mode as well as the process controls to detect each failure mode are listed. For each failure mode, there may or may not be both a prevention control as well as a detection control. A prevention control may be something such as “molding within set parameters.” A detection control may be something such as “visual inspection.”

18. Once all the failure modes of all the general processes have been identified, each failure mode is given a “severity”, “occurrence” and a “detection” rating on a scale of 1 to 10. • More severe failure modes receive higher rankings. • Failure modes which are more likely to occur are given higher rankings. • Those failure modes which are harder to detect are given higher rankings.

19. RPN Once every failure mode is given a ranking for severity, detection and occurance, those three numbers are mulitplied together to give a number referred to as a Risk Priority Number a.k.a. RPN. Those failure modes with the highest RPN numbers are the ones on which the team should focus their efforts for process improvements.

20. As an auditor, what are some of the things I should look for? • Recommended actions up to date • FMEA’s updated as a result of corrective actions • Severity rankings cannot generally be reduced expect via design change • All causes for a given failure mode should have the same severity rankings • All steps in the process flow diagram should be included in the PFMEA

21. Core tool - PPAP Production Part Approval Process

22. What is the PPAP process? When PPAP is mentioned, sometimes are referring to the process of showing documentation and getting their process approved to go itno production for a new product. Sometimes when people refer to a PPAP, they are talking about the package of documents they have prepared. Other times, people will say they are “PPAPing today”, which can mean they are demonstrating a portion of their process to a customer.

23. In general, though, the PPAP process defines a general set of requirements for production part approval to determine if all customer engineering design record and specification requirements are proplerly understood by the supplier and that the process has the potential product consistently meeting these requirements during an actual production run. The PPAP process is used not only between tier-one suppliers and their customers (GM, DCX, Ford) but also between the suppliers themselves.

24. In preparing a PPAP package for submission, there are a number of documents which must be prepared. Some of these include: • Design records • DFMEA • PFMEA • Process flow diagrams • Control plan • Warrant (PSW) • Appearance approval report (AAR)

25. Different customers and different situations require different amounts of documentation to be submitted before approval will be granted. There are five “levels” of PPAP submission, ranging from submitting just a warrant “basically a cover page” up to submitting all 19 pieces of supporting documentation. It should be noted, however, that no matter what level the customer requires, all 19 pieces of supporting documentation need to be completed and retained at the supplier location and be made readily available for customer review.

26. As stated before, part of a PPAP process might involve a “run at rate” which is a demonstration of the process intended to be used to make the parts for the customer once production begins. Once the customer is sufficiently pleased that all the paperwork is thorough and he/she is confident that intended process is going to be capable of producing parts which will meet all the intended requirements at the desired rate, the PPAP may then be signed by the customer and production can begin.

27. As part of an audit, what are some things I should be on the lookout for? • On-going process capability for critical characteristics equal to or greater than that demonstrated in the PPAP package • Same materials used as specified in the original PPAP, unless permission has been granted by the customer otherwise • The process flow matches that called out in the original PPAP package • PPAPs on file for all tier-two suppliers

28. Core tool - APQP Advanced Product Quality Planning

29. What is APQP? • APQP is a structured method of defining and establishing the steps necessary to assure that a product satisfies the customer. Some of the benefits of APQP are: • To direct resources to satisfy the customer • To promote early identification of required changes • To avoid late changes • To provide a quality product on time at the lowest cost

30. There are five basic steps to APQP. These are: • Plan and define the program • Product design and development verification • Process design and development validation • Product and process validation • Feedback assessment and corrective action Like every process, each phase of APQP has specific inputs and specific outputs

31. Phase 1 - Plan and define the program • Inputs • Voice of the customer • Business plan • Benchmarking data • Product and process assumptions • Product reliability studies • Customer inputs • Outputs • Design goals • Quality goals • Preliminary process flow chart • Preliminary list of special characteristics • Management support

32. Phase 2 - Product design and development • Inputs • Design goals • Quality goals • Preliminary process flow chart • Preliminary list of special characteristics • Management support • Outputs • DFMEA • Design verification • Design reviews • Prototype build • Math data • Engineering specifications

33. Phase 3 – Process design and development • Inputs • DFMEA • Design verification • Design reviews • Prototype build • Math data • Engineering specifications • Team feasibility commitment • Outputs • Packaging standards • Process flow chart • Floor plan layout • PFMEA • Pre-launch control plan • Process instructions

34. Phase 4 – Product and process validation • Inputs • Packaging standards • Process flow chart • Floor plan layout • PFMEA • Pre-launch control plan • Process instructions • Management support • Outputs • Production trial run • Measurement systems evaluation • Process capability study • PPAP • Production validation • Production control plan • Quality planning sign-off

35. Phase 5 – Feedback, assessment and corrective action • Inputs • Production trial run • Measurement systems evaluation • Process capability study • PPAP • Production validation • Production control plan • Quality planning sign-off • Outputs • Reduced variation • Customer satisfaction • Delivery and service

36. As an auditor, what are some of the things I look out for? • All records required at each phase maintained and complete • All phases of APQP completed per schedule • Multi-disciplinary approach used

37. Core tool - MSA Measurement Systems Analysis

38. Terms and definitions Measurement: the assignment of number or values to material things to represent the relations among them with respect to particular properties. Gage: any device used to obtain measurements Measurement system: the collection of gages, standards, operations, methods, personnel, environment, etc. used to quantify a unit of measure.

39. True value: the target of the measurement process. It is desired that any individual reading be as close to this value as economically possible.

40. As you can see, a gage is only one part the measurement system. The goal of the measurement system is to produce a measurement of an object which is as close to the “true value” as economically possible. Many factors conspire against us always reaching that true value of the measurement, however. Some of those factors can be variation in how each inspector uses that gage, variation between gages, changes in the environment, variation in how each inspector reads the gage and others.

41. The goal of measurement systems analysis (MSA) is to determine the quality of a measurement system, or in other words, how good the measurement system is in producing measurements compared to the true value of those measurements.

42. Some other terms that are used in the analysis of measurement systems Standard: a reference value or an accepted basis for comparison Resolution: smallest scale of measure or output of an instrument Reference value: accepted value of a characteristic of a part True value: actual value of a characteristic of a part

43. Bias: difference between the observed range of measurements and the reference value As an example, let’s say ten inspectors measure the width of a gage block using a digital micrometer. The average of those ten readings comes out to 3.6 mm. If the reference value of the width of that gage block is 3.5 mm, the bias is 0.1 mm.

44. Stability: The change in bias over time. As an example, let’s say those say ten inspectors go back the next day and they measure the width of that exact same gage block with the same micrometer. This time the average of their readings is 3.62 mm. The day after that, those same ten inspectors measure that same gage block and get an average reading of 3.56 mm. As you can see the bias is not “stable.”

45. Linearity: the change in bias over the normal operating range of the gage As an example, let’s say those ten inspectors use that same digital micrometer to measure the width of a key cylinder. They get an average reading of 15.1 mm while the reference value of the key cylinder is 15.0 mm. They then measure the width of a handle and they get an average reading of 20.5 mm while the refenence value is 20.4 mm. As you can see the measurement system is exhibiting “linearity” because for each average reading, they are off (bias) by the same amount each time over the range of the gage. With a non-linear measurement system, that bias may grow larger or smaller over the range of the gage.

46. Repeatability: variation in measurements obtained with one measuring device when used several times by an appraiser while measuring the exact same characteristic on the same part. • As an example, Bob measured the width of a rod clip five times in the exact same spot. He got the following readings: • 2.45 mm • 2.48 mm • 2.51 mm • 2.49 mm • 2.50 mm

47. Reproducibility: variation in the average measurements made by different appraisers using the same gage measuring one characteristic on one part. • As an example, Bob, Sally and Paige measured the width of a rod clip ten times each using a digital micrometer. They got the following averages: • Bob = 2.53 mm • Sally = 2.49 mm • Paige = 2.51 mm

48. GRR a.k.a. Gage R&R: gage repeatability and reproducibility. It is the combined estimate of measurement system repeatability and reproducibility. GRR is often expressed as %. This is what % the GRR is compared to the tolerance of the part in question. In general, less than 10% GRR is very good. Greater levels of GRR can be acceptable, but will vary based upon company procedures, customer requirements, and so on.

49. As an auditor, what are some of the things I should be on the lookout for? • The results of a GRR study on file for every family of variable gages referenced in all control plans • A new GRR study completed for each family of variable gages completed every year using people who may actually use that gage in a production setting • GRR results that comply with either internal or customer specific requirements

50. Core tool - SPC Statistical Process Control