My Reading on ASQ CQA HB Part V Part 2

Charlie Chong/ Fion Zhang
Part VD1
Achieving Breakthrough Improvement
Building on Shewhart’s notions to develop a systematic method for improvement, Juran distinguished between
sporadic and chronic problems for quality improvement projects (QIPs). Starting from a state of chaos, a QIP
should first seek to control variation by eliminating sporadic problems. When a state of controlled variation is
reached, the QIP should then break through to higher levels of quality by eliminating chronic problems, thereby
reducing the controlled variation. The notions of control and breakthrough are critical to Juran’s thinking. The
following scenario demonstrates this concept: A dart player throws darts at two different targets. The darts on
the first target are all fairly close to the bull’s-eye, but the darts are scattered all over the target. It is difficult for
the player to determine whether changing stance (or any other variable) will result in an improved score. The
darts thrown at the second target are well off target from the bull’s-eye, but the location of the darts is clustered
and therefore predictable. When the player determines what variable is causing the darts to miss the bull’seye,
immediate and obvious improvement should result. The impetus behind Juran’s work is to achieve repeatable
and predictable results. Until that happens, it will be almost impossible to determine whether a quality
improvement effort has had any effect. Once a process is in control, breakthroughs are possible because they
are detectable. The following points are essential to an understanding of variation:
• Everything is the result or outcome of some process.
• Variation always exists, although it is sometimes too small to notice.
• Variation can be controlled if its causes are known. The causes should be determined through the practical
experience of workers in the process as well as by the expertise of managers.
• Variation can result from special causes, common causes, or structural variation. Corrective action cannot be
taken unless the variation has been assigned to the proper type of cause.
For example, in Deming’s bead experiment (white beads = good product, red beads = bad product) the workers
who deliver the red beads should not be blamed; the problem is the fault of the system that contains the red
beads. • Tampering by taking actions to compensate for variation within the control limits of a stable process
increases rather than decreases variation. • Practical tools exist to detect variation and to distinguish controlled
from uncontrolled variation.