An Interrelationship Diagram shows graphically the cause-and-effect relationships that exist among a group of items, issues, problems, or opportunities. It is particularly useful in helping to identify the potential causal relationships that might lie behind a problem that continues to recur despite attempts to resolve it.
A Tree Diagram is a chart that begins with one central item and then branches into more and keeps branching until the line of inquiry begun with the central item is exhausted. The tree diagram, with its branching steps, motivates you to move from the general to the specific in a systematic way.
A Standard Operating Procedure (SOP) is a set of written instructions that document a routine activity that is to be followed by members of an organization. Standard Operating Procedures are essential parts of good quality systems. Sound and well-written SOPs should enhance consistency and reduce human error. Note: sometimes standard operating procedures are referred to as Work Instructions.
A Control Plan is a method for documenting the functional elements of quality control that are to be implemented in order to assure that quality standards are met for a particular product or service. The intent of the control plan is to formalize and document the system of control that will be utilized.
A Run Chart is a basic graph that displays data values in a time sequence (the order in which the data were generated). A run chart can be useful for identifying shifts and trends. A supervisor of a customer service center collects data on the number of complaints that are filed each month. Data for the last several weeks are shown below.
A Run Chart is a basic graph that displays data values in a time sequence (the order in which the data were generated). A Run Chart can be useful for identifying shifts and trends. Example: A supervisor of a customer service center collects data on the number of complaints that are filed each month. Data for the last several months are shown below.
The following formulas are used to compute the Centerlines for Statistical Process Control (SPC) charts.
A Run Chart is a basic graph that displays data values in a time sequence (the order in which the data were
generated). A Run Chart can be useful for identifying trends or shifts in process.
Example: A supervisor of a customer service center collects data on the number of complaints that are filed
each month. Data for the last several months are shown below.
The following formulas are used to compute the Upper and Lower Control Limits for Statistical Process Control (SPC) charts. Values for A2, A3, B3, B4, D3, and D4 are all found in a table of Control Chart Constants.
How fine a measurement is sliced is referred to as Measurement Discrimination.
One way to visualize the amount of measurement discrimination is to look at the range portion of a control chart. It is points (dots) that you need to look at on the chart. You look for the number of strata (parallel layers) of the dots as they spread across the range chart. It is not the count of dots. Instead, it is a count of strata (parallel layers) of dots (you are looking for a minimum of six strata).
