Nonconformance Disposition

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


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


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.


Capability Analysis


Pharmaceutical sampling

Q: Why is a standard capability analysis determined to be best represented by 30 pieces?

I have answered this question by explaining it best represents a normal distribution. But I wonder if this is traceable to an industry standard?

A: You are right that most people associate 30 pieces with the conventional quantity for performing a capability study.  Although I don’t know the origin of this number, I can tell you the following:

  • The number 30 has nothing to do with whether or not the population is normally distributed.
  • In many applications, the number 30 is insufficient to properly model the process.  For example, automotive industry standards published by the Automotive Industry Action Group (AIAG) in their statistical process control (SPC) and production part approval process (PPAP) documents define 100 pieces as the appropriate sample size for an initial capability study (based on 20 subgroups of five or 25 subgroups of four).

I hope you find this helpful.

Denis J. Devos, P.Eng
A Fellow of the American Society for Quality
Devos Associates Inc.
London Ontario

Related Content:

Statistics in Pharmaceutical Development and ManufacturingJournal of Quality Technology,  open access

An overview is given of the use of statistical thinking and methods in the research and development and manufacturing functions in the pharmaceutical industry. Four case studies illustrate how these issues work in real life settings. A synopsis of these issues concludes that the technical nature of pharmaceutical development and manufacturing offers opportunities for the effective use of statistical methods leading to both process-development understanding and product-quality improvement.

Build a Usable Process Capability Database, Six Sigma Forum Magazine, Open Access

Design for Six Sigma requires that designs meet customer needs without sacrificing quality. A number of statistical tools can be used to produce process capability data to enable development teams to design products that can be produced at reasonable cost on existing equipment. However, setting up and using a process capability database is poorly understood and as a result, it is seldom used. To create a successful database, it is necessary to get management support, build the right data structure, collect the right data, and use the data correctly. A correctly designed database will allow the product development team to focus its efforts only on those tolerances in which the capability is unclear or in which function or cost improvements can be achieved.

Exploring ACM and BPM

Q: Can someone explain how to use Adaptive Case Management (ACM) and how to incorporate it in a process diagram?

A: First, let’s take a look at Business Process Management (BPM), which approaches the problem of improving an organization’s work from a strongly process centric point of view.  The first thing you think about is the process.  In a certain way, it is the process which defines whether two instances are similar or not.

Data flows into and out of a process. The process represents the goal of a particular sequence of actions, but that goal is not itself an information resource.  The process instance contains process relevant data, as well as application data, but it generally assumes that the data duplicates data that has its source elsewhere. This is the main point about “integration” of the process into other information resources.

 BPM might be visualized as in this diagram:

 Adaptive Case Management (ACM) also tries to improve the performance of an organization, but instead of considering the process to be primary, it is the case information that is primary. This case information is an information resource which will be accessed over the duration of use, and in many situations will become the official record (system of record) for that work.

There can be processes, but the processes are brought to the case, and run in the context of the case, rather than the other way around.

 An ACM system might be envisioned as in this diagram:

Both approaches deal with:

  • Process relevant data
  • Allowing for process requirements
  • Producing historical information that can be analyzed to determine the efficiency of the group involved
  • Availability to multiple people
  • People who are notified of tasks
  • Capturing the results of tasks

At a technical level, these are similar or perhaps even identical. But at a methodological level, i.e., how you approach a given problem, they are at the opposite ends of a spectrum.

In BPM, the process is primary.  Thus, it is predetermined and static, while the data flows through it.  However, with ACM it is the data that is primary.  This tends to persist for a long period of time, but the processes are brought to the data. In many cases with ACM, the processes are not even fully predefined, but must be defined on the fly.

The net result is that BPM and ACM are useful for different kinds of business situations. For example:

  • Highly predictable and highly repeatable business situations are best supported with BPM, e.g., signing up for cell phone service: it happens thousands of times a day, and the process is essentially fixed.
  • Unpredictable and unrepeatable business situations are best handled with ACM, e.g., investigation of a crime requires following up on various clues, going down various paths which are not predictable in advance.   There are various tests and procedures to use, but they will be called upon only when required.

Jack B. ReVelle, Ph.D.
A Consulting Statistician
ReVelle Solutions, LLC
Santa Ana, CA