Auditing accuracy

Q: I am in the process of examining all aspects of my company’s auditing and inspection processes for our healthcare and hospitality clients, including developing and quantifying standards.

We’re in a growth phase and want to ensure our auditors’ assessments are consistent and accurate, and that the standards within the audits are defined as clearly as possible. Where can I find a knowledgeable resource to objectively assess our auditing and inspection forms and processes?

Monte Fulton
Plano, TX

A: To identify a knowledgeable resource for assessing your auditing and inspection forms and processes, you first need to identify the goals of your company’s auditing and inspection function.

You said you want to improve the consistency and accuracy of your auditors, and ensure audit standards are clearly defined. Are there any other relevant company goals, such as error reduction, improvement in patient satisfaction, regulatory compliance, Joint Commission certification, a Baldrige award, ISO 9001 certification or IWA-1 implementation?

Improving auditor consistency and accuracy is challenging. Providing detailed audit forms to each auditor will help ensure auditors are asking the same questions. But it is difficult to ensure the auditors’ evaluations of the answers are consistent. A consulting company that has expertise in process auditing may be an appropriate resource.

To evaluate your auditing inspection forms and processes, including audit standards, you will need a subject matter expert who is knowledgeable about your industry and the applicable compliance requirements (regulatory and certification) for your company. Depending on your specific needs, there are a few resources to consider.

The ASQ Healthcare Division has a speaker’s bureau on its website.1 Each speaker lists his or her areas of expertise, and some may be willing to provide consulting services. The Joint Commission, in addition to providing accreditation and certification services, also provides consulting services.

Many of the organizations that provide ISO 9001 certification services have separate businesses that provide consulting services, some of which claim expertise in auditing the healthcare industry. There are also numerous consulting businesses that focus on the healthcare industry and can be found via a simple internet search.

If your budget only allows for self-assessment, you can find many articles on the internet, including a Wikipedia article on clinical audits that contains useful references.2 Also, the ASQ Store has a variety of standards and books on auditing and healthcare, which you can find by entering those keywords into the search function.3

As a final suggestion, look to other organizations similar to yours. Are there any that have achieved recognition or certification for their services? Perhaps their auditing and inspection function helped the company achieve that. You may be able to establish a relationship with them to share information and obtain the assessment you need.

Ken Cogan
Navis Pack & Ship MD-1106
Annapolis Junction, MD


  1. ASQ Healthcare Division, "Speaker’s Bureau," www.asq.org/health/quality-information/speakers-health.html.
  2. Wikipedia, "Clinical audit," http://en.wikipedia.org/wiki/clinical_audit.
  3. ASQ, "ASQ Store," www.asq.org/quality-press/index.html.

Looking for stability

Q: How are control charts related to process capability in a manufacturing environment? What is the solution when a control chart is stable but the process capability is not?

Adil Anwar
Punjab, Pakistan

A: Control charts provide a way to understand process behavior over time, while process capability is a one-time measure of what the process has produced over time.

Control charts provide the necessary estimates to determine process capability and must be stable to provide good estimates. Additionally, a stable control chart indicates the process is consistent and predictable, which is desirable over randomness and surprises.

Sometimes, a control chart can be stable, but the process capability is inadequate. Typically, process capability is defined by a set of specifications of tolerances. A process may be stable and predictable but has more variation than is desired in the final product. Reducing variation, and even centering a process, requires certain tools to define and minimize variation—for example, design of experiments and fishbone diagrams.

Often, I’ve seen situations with a process that is stable and yet is still variable over time. I’ve also seen process capabilities that are good, but the process is unstable and yet still produces adequate parts. Sometimes, you need to ask whether the specifications are realistic and set at the proper levels.

Tony Gojanovic
Packaging quality specialist

Under control

Q: Could you point me to some information regarding the control charting of laboratory instruments? Also, after you’ve made adjustments or performed maintenance procedures on an instrument, resulting in a run of points above or below the mean, how do you know when it’s time to recalibrate? Does the count start over from this point of action? Are quality control check samples ever readjusted when runs above or below the mean don’t come into tolerance?

Rick Patulski
Liverpool, NY

A: It is difficult to determine exactly what application you have in mind based on the question. So let’s see if I can provide the body of knowledge you seek through some references. One of these resources should be able to help with what you want to implement.

First, let’s look at some references so you can choose the right control charts for the instruments you are monitoring:

  • Introduction to Statistical Quality Control by Douglas Montgomery provides some real-life industrial examples.1
  • The Desk Reference of Statistical Quality Methods, second edition, by Mark L. Crossley is a quick reference for different statistical methods.2

It might also help to know the definition of calibration according to ISO Guide 99:2007:

Calibration operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication.

Note 1. A calibration may be expressed by a statement, calibration function, calibration diagram, calibration curve or calibration table. In some cases, it may consist of an additive or multiplicative correction of the indication with associated measurement uncertainty.

Note 2. Calibration should not be confused with adjustment of a measuring system, often mistakenly called "self-calibration," nor with verification of calibration.

Note 3. Often, the first step alone in the above definition is perceived as being calibration.3

Adjustment is a decision that comes after calibration. Making the decision of when to adjust depends on several factors. There are certain items, such as mass weights and gage blocks, that cannot be adjusted. The calibration of those items states the positive or negative difference from the standard value (Note 1), but pay specific attention to Note 2.

Several methods for establishing calibration intervals can be found in "NCSL Recommended Practice RP-1, Establishment and Adjustment of Calibration Intervals"4 and "ILAC-G24:2007—Guidelines for the determination of calibration intervals of measuring instruments."5 The NCSL Z540.3-2006 Handbook also details some methods for calibration decisions and references probability of false accept below 2%.6

Dilip Shah
E = mc3 Solutions
Medina, OH


  1. Douglas Montgomery, Introduction to Statistical Quality Control, Wiley, 2000.
  2. Mark L. Crossley, The Desk Reference of Statistical Quality Methods, second edition, ASQ Quality Press, 2007.
  3. International Organization for Standardization, ISO/IEC Guide 99:2007—International vocabulary of metrology—Basic and general concepts and associated terms (VIM), www.iso.org/iso/catalogue_detail.htm?csnumber=45324.
  4. National Conference of Standards Laboratories, "NCSL Recommended Practice RP-1, Establishment and Adjustment of Calibration Intervals," Nov. 15, 1989.
  5. International Laboratory Accreditation Cooperation, "ILAC-G24:2007—Guidelines for the determination of calibration intervals of measuring instruments," 2007, www.ilac.org/documents/ILAC_G24_2007.pdf (case sensitive).
  6. National Conference of Standards Laboratories, NCSL Z540.3-2006 Handbook, 2006.

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