Question

Problem 7 [Pencil version] Under what practical situations, the following control charts would be useful? Write one line for each question. Avoid jargon. (1) I-MR charts (2) DNOM chart (3) Zone chart (4) G chart (5) T chart

Answer 1

Answer:

Given that:

1) I-MR charts :

In statistical quality control the individual moving range chart is a type of control chart used to monitor variables data from a business or industrial process for which it is impractical to we rational subgroups.

2) DNOM chart:

Short run control charts are DNOM. Traditional SPC used 20 or more data points to develop a control chart. These are also known a Deviation from normal charts i.e (DNOM chart) . So if the first group of parts has a target value 74mm. We measure each part and determine variation from the target.

3) Zone chart:

We zone chart to monitor the mean of our process with a control chart that uses sigma intervals or zones and a cumulative scoring system instead of tests for special causes to detect out-of-control points.

4) G chart:

The G control chart is used to analyze rare events. If the events are very rare, the traditional attribute control charts (p,n,p,s or u) may not be very useful, therefore we use G chart in such situation.

5) T-chart:

The T-chart creates a picture of a process over time each point on the chart represents on amount of time that has passed since a prior occur range of rare event. The time unit might be hours ,days, weeks,months etc.