Comments on: Good and Bad Variation http://www.reformingprojectmanagement.com/2003/09/14/241/ The magazine for the project age Fri, 04 Jul 2008 13:37:55 +0000 http://wordpress.org/?v=2.0.5 by: Frank Patrick http://www.reformingprojectmanagement.com/2003/09/14/241/#comment-51 Wed, 31 Dec 1969 16:00:00 +0000 http://www.reformingprojectmanagement.com/2003/09/14/241/#comment-51 And another thing... Good variation and bad variation. Opportunity and Risk? Being open to one and vigilant about the other. And another thing…

Good variation and bad variation.

Opportunity and Risk?

Being open to one and vigilant about the other.

]]> by: Tariq Abdelhamid http://www.reformingprojectmanagement.com/2003/09/14/241/#comment-52 Wed, 31 Dec 1969 16:00:00 +0000 http://www.reformingprojectmanagement.com/2003/09/14/241/#comment-52 Wonderful topic...other sources sources of breakdowns, or variability, include late delivery of material and equipment, design errors, change orders, scope changes, equipment and tool malfunctions, improper crew utilization, labor strikes, environmental effects (rain, hot, cold, wind, humid), poorly designed production systems, and accidents. Deming and other Quality movement gurus have warned about two kinds of variation: 1. Common-cause variation (aka as chance variation or chronic variation).- This is an inherently random source of variation. It is a manifestation of the process capability and can't be avoided unless the process capability is increased, i.e., the whole process/product has to be re-designed - A major change! 2. Special Cause variation (aka assignable variation or sporadic variation). - This is a sign that the existing process is not operating according to its intended/specified/designed capability. It is an unusual but controllable source of variation that requires a correction to bring the process or procedures back to its normal levels. This kind has to be addressed right away but does not require a major change in the existing process but more of a calibration to the existing process. Deming asserts that �the difference between these is one of the most difficult things to comprehend� and that it is a futile attempt to address quality problems without understanding the two types of variations. Therefore, Deming recommended that special cause variation be addressed first before addressing common cause variation. Sorry for the length...I got carried away....Best, Tariq Wonderful topic…other sources sources of breakdowns, or variability, include late delivery of material and equipment, design errors, change orders, scope changes, equipment and tool malfunctions, improper crew utilization, labor strikes, environmental effects (rain, hot, cold, wind, humid), poorly designed production systems, and accidents.

Deming and other Quality movement gurus have warned about two kinds of variation:
1. Common-cause variation (aka as chance variation or chronic variation).- This is an inherently random source of variation. It is a manifestation of the process capability and can’t be avoided unless the process capability is increased, i.e., the whole process/product has to be re-designed - A major change!

2. Special Cause variation (aka assignable variation or sporadic variation). - This is a sign that the existing process is not operating according to its intended/specified/designed capability. It is an unusual but controllable source of variation that requires a correction to bring the process or procedures back to its normal levels. This kind has to be addressed right away but does not require a major change in the existing process but more of a calibration to the existing process.

Deming asserts that �the difference between these is one of the most difficult things to comprehend� and that it is a futile attempt to address quality problems without understanding the two types of variations. Therefore, Deming recommended that special cause variation be addressed first before addressing common cause variation.

Sorry for the length…I got carried away….Best, Tariq

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