ASTM D4583-95(2004)

Standard Practice for Carbon Black—Calculation of Process Indexes From an Analysis of Process Control Data

SIGNIFICANCE AND USE
This practice will provide the following: (1) a statistical summary of individual production run data plotted on a control chart; (2) a statistical summary of data from multiple production runs; (3) a procedure to relate the average and variation of these data groups to specification limits, and (4) indexes for comparing different manufacturing units for projecting future capabilities or as historical reference.
SCOPE
1.1 This practice covers (1) a statistical procedure for analyzing the test data generated in the statistical process control of a carbon black manufacturing process; (2) a format for reporting process capability determined from the analysis of control chart data of an individual production run, and (3) a format for reporting process performance determined from the analysis of control chart data of an individual production run.
1.2 This practice specifically applies to the analysis of pelleted carbon black samples taken during the manufacturing process prior to storage. This practice does not apply to shipment samples taken from hopper cars or other containers or packages.
1.3 This practice is specifically designed to be used for those test methods given in Classification D 1765 which specify target values. However, these techniques are applicable to other test methods on carbon black.
1.4 This practice describes the calculation for two methods of determining capability factors from an analysis of process control data.
1.4.1 Process capability (Cp) is a measurement of variation calculated from the process control chart data with the use of an estimated standard deviation (σ) from the mean value of the moving range (R) chart. The calculation of the process capability (Cp and Cpk) indexes can be used as historical information or to predict future performance of the process, but are only valid when the process is in a state of statistical control.
1.4.2 Process performance (Pp) is a measurement of variation calculated from the process control chart data using sample standard deviation(s). The calculation of the process performance (Pp and Ppk) indexes are used for a historical reference of a process' performance and does not require a state of statistical control.

General Information

• Status: Historical
• Publication Date: 31-May-2004
• ICS: 83.040.20 - Rubber compounding ingredients
• Technical Committee: D24 - Carbon Black
• Drafting Committee: D24.61 - Carbon Black Sampling and Statistical Analysis

Relations

• Replaces: ASTM D4583-95(1999) - Standard Practice for Carbon Black-Calculation of Process Indexes From an Analysis of Process Control Data
• Effective Date: 01-Jun-2004
• Replaced By: ASTM D4583-95(2009) - Standard Practice for Carbon Black—Calculation of Process Indexes From an Analysis of Process Control Data
• Effective Date: 01-May-2009

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D4583–95 (Reapproved 2004)
Standard Practice for
Carbon Black—Calculation of Process Indexes From an
Analysis of Process Control Data
This standard is issued under the fixed designation D 4583; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This practice covers (1) a statistical procedure for 2.1 ASTM Standards:
analyzing the test data generated in the statistical process D 1765 Classification System for Carbon Blacks Used in
control of a carbon black manufacturing process; (2) a format Rubber Products
for reporting process capability determined from the analysis
3. Terminology
of control chart data of an individual production run, and (3)a
,
3 4
3.1 Definitions of Terms Specific to This Standard:
format for reporting process performance determined from the
analysis of control chart data of an individual production run. 3.1.1 average moving range ( R )—the arithmetic mean of n
moving ranges, R = (R/n.
1.2 This practice specifically applies to the analysis of
pelleted carbon black samples taken during the manufacturing 3.1.2 Cpk index—an index that indicates how well the
common cause process variability is actually contained within
process prior to storage. This practice does not apply to
shipmentsamplestakenfromhoppercarsorothercontainersor the specifications. (See 6.4.)
3.1.3 moving range (R)—the absolute difference between
packages.
1.3 This practice is specifically designed to be used for consecutive, individual test values.
3.1.4 Ppk index—indicates how well the common and
those test methods given in Classification D 1765 which
specify target values. However, these techniques are applicable special cause process variability is actually contained within
the specifications. (See 6.6.)
to other test methods on carbon black.
1.4 This practice describes the calculation for two methods 3.1.5 process capability index (Cp)—an index that com-
paresthemagnitudeofcommoncauseprocessvariabilitytothe
of determining capability factors from an analysis of process
range of upper and lower specification limits (USL and LSL)
control data.
1.4.1 Process capability (Cp) is a measurement of variation without regard to where the process is centered; Cp
index = (USL − LSL)/(6sˆ). (See 6.3.)
calculated from the process control chart data with the use of
an estimated standard deviation (sˆ) from the mean value of the 3.1.6 process performance index(Pp)—an index that com-
pares the magnitude of common and special cause process
moving range (R) chart. The calculation of the process capa-
bility (Cp and Cpk) indexes can be used as historical informa- variability to the range of the upper and lower specification
limits (USL and LSL) without regard to where the process is
tion or to predict future performance of the process, but are
only valid when the process is in a state of statistical control. centered; Pp index = (USL − LSL)/(6s). (See 6.5.)
1.4.2 Process performance (Pp) is a measurement of varia-
4. Significance and Use
tion calculated from the process control chart data using
4.1 This practice will provide the following: (1) a statistical
sample standard deviation(s). The calculation of the process
summary of individual production run data plotted on a control
performance (Pp and Ppk) indexes are used for a historical
reference of a process’ performance and does not require a
state of statistical control.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
1 3
This practice is under the jurisdiction of ASTM Committee D24 on Carbon Manual on Presentation of Data and Control ChartAnalysis, STP15D, ASTM
Black and is the direct responsibility of Subcommittee D24.61 on Carbon Black International, 1976.
Sampling and Statistical Analysis. Ford Motor Company Manual on “Process Capability and Continuing Process
Current edition approved June 1, 2004. Published June 2004. Originally Control,” Publication No. 80-01-251. Available in packs of five from Ford Motor
approved in 1986. Last previous edition approved in 1999 as D 4583 – 95 (1999). Company, Statistical Methods Publications, P.O. Box 1000, Plymouth, MI 48170.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4583–95 (2004)
chart; (2) a statistical summary of data from multiple produc- recommended for estimating a process capability standard
tion runs; (3) a procedure to relate the average and variation of deviation. In that case, the number (n) of moving ranges
these data groups to specification limits, and (4) indexes for averaged will be 29.
comparing different manufacturing units for projecting future
5.2.2 CalculateCp andCpk as shown in 6.3 and 6.4.TheCp
capabilities or as historical reference.
index and the Cpk index must be greater than 1.00 in order to
indicate the capability of the process to meet the established
5. Procedure
specifications.TheCpk index is inherently less than or equal to
the Cp index (for one-sided specifications, only the Cpk index
5.1 Sampling:
is applicable).
5.1.1
...