Rounding Numbers and Specifications

Automotive inspection, TS 16949, IATF 16949

Question

If I have a data collection form and the data inputs are whole numbers, should the report then use rounded whole numbers rather than to 2 decimals points?  I’d like to be accurate.

Answer

It depends on the specification.  If the specification is a whole number, then each reporting value should be in a whole number.  The issue comes in when inspection, measurement, and test equipment (IM&TE) gives a read-out in decimals, as they should.  (remember the requirement that the IM&TE should be more accurate than the desired result).

For example: if the specification is XX, then the test result should be reported in XX.  If the specification is XX.X, then the result should be reported in XX.X (one decimal place).

Not doing so can lead to problems.  If the specification is, for example 8 – 10, then a result of 8, 9 or 10 is passing.  If the IM&TE gives a result of 10.1 and you record 10.1 then you open the door for interpretation by others.  The best thing to do is define the recording of test results in the test procedure / method.

Once when I was being audited, the ISO auditor claimed that the company was accepting out-of-specification test results.  The specification was 0.01 max.  The test instrument gave a digital read out in the 4th decimal place and the technician record all 4.  The test result was 0.0102.  The auditor claimed that was over the max or 0.01. Boy did I have an argument with him (I won).  After that,the technicians were trained to round to the readings and record only to 2 decimal places (i.e. significant digits)  This was also added to the test instruction.

James Werner

Process Review Requirement in 9001?

About ASQ's Ask the Standards Expert program and blog

Question

Is there a requirement in the new 9001:2015 standards for annual monitoring/reviews of processes? What are any such requirements for process reviews?

Answer

First, there is no requirement to do anything annually.  Rather it is an expectation to do certain things such as calibration at least annually. The subject requirement is in section 9.3 Management review. Specifically section 9.3.2 Management review inputs includes at part (3) “process performance and conformity of product and services”.

What is commonly done is to create key performance indicators  (KPI’S) for each quality system process and these KPI’s are periodically reviewed (at least annually) during a management review.  Any process not meeting its KPI is looked into for improvement.

There are many articles and books written on this subject and available on the web.

James Werner

Click here for more information about KPIs and here for information about management reviews.

Internal Auditing Roles?

Manufacturing, inspection, exclusions

Question

I’m quality manager for R&D department and have several persons as Software Quality Assurance for our software development process. My question is can I act as Internal Auditor to audit the compliance of ISO 9001: 2015 requirements and the software development process execution?

Answer

Let’s look at this differently.  Say you are the quality manager and have several persons doing final product testing in a test lab. Clearly you are not impartial – you have a responsibility of the persons doing the testing.  Since you cannot be impartial, you cannot act as the internal auditor or even be on the auditing team.

James Werner

Click here for more resources about internal audits.

ISO 9001 and M & A

Reporting, best practices, non-compliance reporting

Question

I would like to know how ISO 9001 management system could facilitate a merger & acquisition. By speaking a common language and using the same exigencies, do you think ISO 9001 could facilitate this type of operation?

Answer

I’ve done this in the past but not with ISO 9001, instead using FDA Part 820 Quality System Regulation.  I created a checklist from the regulation and then audited the facility being merged / acquired.  This was done to determine the state of the quality management system and what needed to be done (including costs) to ensure the facility was in compliance.

James Werner

Nonconformance Disposition

Chart, graph, sampling, plan, calculation, z1.4

Question

Should the person writing a non-conformance also be the person who dispositions the same non-conformance?

Answers

From John Surak:

This question is interesting.  In addition, there may be a lack of information to properly answer the question.  There is nothing in ISO 9001:2015 that prohibits the person who wrote the non-conformance from ensuring that non-conformance is addressed in an effective manner.  However, several questions remain.  Why did an individual write a non-conformance on one’s self?  Why did the person just take actions to eliminate the non-conformance without having to implement a correction or corrective action process?  This issue would be an interesting discussion during an audit, and it may lead to an audit trail that discusses leadership and commitment.

John G. Surak, PhD

From George Hummel:

This answer depends upon how you define “dispositions.”  If you mean take the corrective action, then no.  If you mean determines the effectiveness and evaluates the results, then yes.

Click here for more resources about nonconformances.

 

ISO 9001: 2015 Clause 8.3.4 and Product Design

 

PLCs, programmable logic controllers

Question

My company is implementing ISO 9001:2015 and my question is regarding Clause 8.3.4 d. Our company designs product for only 20% of our customer base. We do not have a validation process. We do send a prototype to the customer to test the part for a period of time to approve the design. In determining the scope of our organization, can we exclude the validation process and still become ISO 9001:2015 certified?

Answers

From John Surak:

This organization is involved in product design.  Therefore, the product design cannot be excluded.  However, the organization needs to review the validation clause.  8.3.4d states the following:   “validation activities are conducted to ensure that the resulting products and services meet the requirements for the specified application or intended use.”  It should be noted that neither 8.4.3d not the validation refences in ISO 9001 do not prescribe a method on how to conduct validation.  It would appear that the company has some sort of process they use to develop the prototypes.  This process should be codified or documented so that it is done in a consistent manner and in a way to ensure that the customer needs are met.

John G. Surak, PhD

From George Hummel:

Basically, you are outsourcing validation.  Therefore, you need to control that process per 8.4. I would not accept the exclusion. In the future, you may have a customer that requires you to do the validation. However, the final answer would be provided by your certification body.

Click here for more resources about ISO 9001: 2015.

 

 

 

Z 1.4 Inspection Levels

Pharmaceutical sampling

Question

I am using a reduced switching rule and I don’t understand the meaning of the numbers in the first box. Total noncomforming less than limit number? What’s my limit number?Does production stability mean capability? Would I use 1.33?  The table has an arrow to reduced, so would I move to the next box?

Answer

The ANSI/ASQ Z1.4 standard has three inspection levels: normal, reduced and tightened inspection.  Initially you start at normal inspection, and can move to either tightened or reduced inspection depending on how lots are dispositioned.  Based on Figure 1 of the standard, the determination to move amongst the levels can be ascertained.  When you get to the reduced inspection level (Table II-C), you need to read the footnote (†).  It states “If the acceptance number has been exceeded, but the rejection number has not been reached, accept the lot, but reinstate normal inspection.”

A stable process or production is less about a capability index, and more about the control chart of the data showing a stable process.  In other words, the process is stable over time.

Steven Walfish

For more information about inspection, please view the resources found here.

Confidence Levels

 

Data review, data analysis, data migration

Question

I would like to confirm if ASQ Z1.4-2008 attribute tables are calculated based on 95% confidence level? I am using Table II-A, on page 11.

Answer

ANSI/ASQ Z1.4 tables are not technically calculated based on a 95% confidence level.  The technical definition of AQL is the quality level that is the worst tolerable process average when a continuing series of lots is submitted for acceptance sampling.  Some interpret it to mean if a lot has AQL percent defective or less, a lot would have a high probability of being accepted based on the sampling plan.  The standard does not specify the probability of acceptance explicitly.  The operating characteristic curve (OC Curve and the tables define the AQL as the percent defective that has a 95% probability of acceptance.  So though it is not a 95% confidence level, it is a 95% probability of acceptance.

Steven Walfish

For more information about AQL, please view the resources here.

Zero Acceptance Number Sampling Plans

Airplane, aerospace, AS9100

Question

Regarding Nicholas Squeglia’s Zero Acceptance Number Sampling Plans, in the 4th edition for lot size 151-280 (1% AQL), a sample size of 20 is provided.  However, in the 5th edition, for the same lot size 151-280 and AQL of 1%, the sample size is 29. Which is correct – a sample size of 20 or 29?

Answer

In the 5th edition of Nicolas Squeglia’s book, he mentions on page xii the rationale of the change in sample sizes.  From  the 5th edition, “in the early 2000’s, a large aerospace manufacturer was given permission by ASQ to reproduce the c=0 sampling table.  They modified the table by changing several sample sizes, and for convenience it was therefore originally decided to carry those modifications into the fifth edition.”

Table 1a is the original tables (4th edition and previous) which has the sample size of 29.  Use this table unless otherwise specified by contract.

Table 1b is the modified table which has a sample size of 20.

Thanks

Steven Walfish

Calibration Questions

Automotive inspection, TS 16949, IATF 16949

Question

I work at a hydraulic cylinder manufacturer. The company has homemade thread and ring gages in house that we are using for production that are not sent out for calibration but have a homemade master that is used to check them with once a year which does not get sent out either. I have been here 6 months and am thinking these gages and masters are a violation of ISO. Am I correct?

Answer

The short answer is yes. The intent of ISO 9001:2015’s subclause 7.1.5 is to ensure that your company determines and provides suitable resources to ensure valid and reliable monitoring and measuring results, when evaluating the conformity of your products; and 7.1.5.2’s that is to ensure that your company provides measurement traceability when it is a requirement or when your company determines it to be necessary to have confidence in the validity of the measurement results. It seems that your practice for controlling the homemade thread and ring gages cannot fully fulfill those purposes. This is how I would address the situation:

  1. Assign a unique identifier to each homemade thread and ring gage. Maybe you can do that through your Document Control process.
  2. Ensure that those gages are protected from deterioration or damage when they are not in use.
  3. Have the homemade master measured by a service able to provide you with reliable certified measurements. That will make that gauge traceable to national or international standards. It will also allow you to demonstrate that the piece is fit for its intended purpose.  That means, you will be able to use this piece as the standard during the in-house calibration of the rest of the gages.
  4. Conduct an “in-house calibration” of each gage you use in production. You will need to issue an in-house calibration certificate for each one of those pieces, indicating on those documents how you achieve traceability to NIST or equivalent. If possible, identify the error for each one of those individual measurements you perform during calibration. Do not forget to include a statement indicating that the gauge was found suitable/unsuitable for use. That will demonstrate that each gage is fit for its intended purpose.
  5. Include ALL the gages in your calibration program. Make them subject to all the applicable provisions of your Quality System.

This approach will allow you to demonstrate that your thread and ring gages are properly controlled and maintained. If controlling those gages has not been an issue in the past, there is no guarantee that the situation will remain the same in the future. That is managing risk 😉

Aura Stewart

For more information about calibration, please see the resources here.