Statistical Process Control (SPC) is the equivalent of a histogram plotted
on it's side over time. Every new point is statistically compared with
previous points as well as with the distribution as a whole in order to
assess likely considerations of process control (i.e. control, shifts, and
trends). Forms with zones and rules are created and used to simplify
plotting, monitoring, and decision making at the operator level. SPC
separates special cause from common cause variation in a process at the
confidence level built into the rules being followed (typically 99.73% or 3
sigma).
Statistical process control is the application of statistical methods to
identify and control the special cause of variation in a process.
Who: The
process owner should be able to recognize when to add, monitor, change, and
remove SPC charting of their processes.
What:
Statistical Process Control (SPC) is the equivalent of a histogram plotted
on it's side over time. Every new point is statistically compared with
previous points as well as with the distribution as a whole in order to
assess likely considerations of process control (i.e. control, shifts, and
trends). Forms with zones and rules are created and used to simplify
plotting, monitoring, and decision making at the operator level. SPC
separates special cause from common cause variation in a process at
the confidence level built into the rules being followed (typically 99.73%
or 3 sigma).
Why: All
processes have a tendency to shift and drift. Key processes must be
controlled and monitored to assure that they don't change. SPC is often a
great tool often used to effectively do that.
Where: SPC
should be implemented on all key processes where the risk of losing control
outweighs the cost of implementing SPC. SPC costs include development of
charts and process specific rules, training operators on SPC, and
on-going data collection and monitoring costs.
When: SPC
should be implemented ... SPC should be updated as appropriate based on
risks, samples needed, opportunities for change, etc.
How:
How much:
How is SPC
Communicated:
Training:
Critical
success factors:
Controlled:
Initial setup,
sample size selection, on-going re-evaluation of control limits,
Collection of
knowledge
The process of
developing, applying, and re-evaluating SPC inititives should also be
continuously improved upon.
Please
contact Kim Niles.
Personal Experience of Kim Niles.
See related
living papers:
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