🚀 go-pugleaf

ThomCycle@aol.com wrote:

> I am assuming the  process with Cpk=.19 is stable.

Yes this process is in statistical control, it took over a year and a half to
bring it into control. Reduction of average range = 51.1%

> Can other methods (e.g., a histogram) be shown to the employees to show them
> they have a stable process but it's not meeting the spec much of the time?

The control charts are enough, the employees are very proud of their improvement
efforts.

> Who audits conformance to specification if the customer doesn't care?  Can we
> use simpler tools at the onset of process knowledge?

No one audits conformance to specifications for the proportioning of concrete
mixtures, if conformance audits were done then the specifications would have bee
 n
changed some time ago. I suspect that the specifications (ASTM C94 not C33 as I
stated in previous post) have been on the books unchanged for a long time, even
though ASTM committees must as stated in the bylaws either drop, modify or
re-approve the standards every five years.

Quality Control in the concrete construction industry is in the dark ages compar
 ed
to almost any other industry. I am publishing a case study paper about the use o
 f
SPC, in this paper I stress prevention rather then inspection which is a new
concept in concrete construction.

> Can we use simpler tools at the onset of process knowledge?

The simpler the better depending on you situation and the nature of the process,
criticality etc.

Aloha
Alan B Crammatte
Quality Coordinator
Hawaiian Cement
alanc@maui.net    acrammat@hawaiiancement.com