MNO2602
Assignment 4 Semester 1 2025
Detailed Solutions, References & Explanations
Unique Number:
Due date: May 2025
QUESTION 1
1.1
Random variation (also called common cause variation) refers to the natural, inherent
fluctuations that occur in a process due to countless small, uncontrollable factors. These
variations are expected and typically fall within control limits. For example, minor
differences in temperature or material properties in a manufacturing process can cause
random variation. These do not signal a problem with the process.
In contrast, nonrandom variation (or special cause variation) arises from identifiable and
controllable sources outside the normal process. These variations are not part of the
system’s natural fluctuation and usually indicate that something has changed or gone
wrong. Examples include equipment malfunction, human error, or defective raw
materials. Nonrandom variation causes data points to fall outside control limits or display
unusual patterns, signaling a need for corrective action.
Terms of use
By making use of this document you agree to:
Use this document as a guide for learning, comparison and reference purpose,
Terms of use
Not to duplicate, reproduce and/or misrepresent the contents of this document as your own work,
By making use of this document you agree to:
Use this document
Fully accept the consequences
solely as a guide forshould you plagiarise
learning, reference,or and
misuse this document.
comparison purposes,
Ensure originality of your own work, and fully accept the consequences should you plagiarise or misuse this document.
Comply with all relevant standards, guidelines, regulations, and legislation governing academic and written work.
Disclaimer
Great care has been taken in the preparation of this document; however, the contents are provided "as is" without any express or
implied representations or warranties. The author accepts no responsibility or liability for any actions taken based on the
information contained within this document. This document is intended solely for comparison, research, and reference purposes.
Reproduction, resale, or transmission of any part of this document, in any form or by any means, is strictly prohibited.
, +27 67 171 1739
QUESTION 1
1.1
Random variation (also called common cause variation) refers to the natural,
inherent fluctuations that occur in a process due to countless small, uncontrollable
factors. These variations are expected and typically fall within control limits. For
example, minor differences in temperature or material properties in a manufacturing
process can cause random variation. These do not signal a problem with the
process.
In contrast, nonrandom variation (or special cause variation) arises from identifiable
and controllable sources outside the normal process. These variations are not part
of the system’s natural fluctuation and usually indicate that something has changed
or gone wrong. Examples include equipment malfunction, human error, or defective
raw materials. Nonrandom variation causes data points to fall outside control limits
or display unusual patterns, signaling a need for corrective action.
In summary, random variation is expected and stable, while nonrandom variation is
unusual and requires investigation.
1.2
When using a process control chart, several nonrandom signals can indicate that
the process is out of control:
1. A single point outside the control limits: This is the most obvious signal of
nonrandom variation and suggests a significant shift in the process.
2. A run of seven or more points on one side of the centre line: This may
indicate a gradual drift in the process mean, caused by a systematic issue.
3. A trend of increasing or decreasing points: A continuous upward or
downward pattern suggests that the process is changing over time.
4. Cyclic patterns or regular repeating patterns: These may indicate
external influences such as temperature changes or shift-based performance
issues.
Disclaimer
Great care has been taken in the preparation of this document; however, the contents are provided "as is"
without any express or implied representations or warranties. The author accepts no responsibility or
liability for any actions taken based on the information contained within this document. This document is
intended solely for comparison, research, and reference purposes. Reproduction, resale, or transmission
of any part of this document, in any form or by any means, is strictly prohibited.
Assignment 4 Semester 1 2025
Detailed Solutions, References & Explanations
Unique Number:
Due date: May 2025
QUESTION 1
1.1
Random variation (also called common cause variation) refers to the natural, inherent
fluctuations that occur in a process due to countless small, uncontrollable factors. These
variations are expected and typically fall within control limits. For example, minor
differences in temperature or material properties in a manufacturing process can cause
random variation. These do not signal a problem with the process.
In contrast, nonrandom variation (or special cause variation) arises from identifiable and
controllable sources outside the normal process. These variations are not part of the
system’s natural fluctuation and usually indicate that something has changed or gone
wrong. Examples include equipment malfunction, human error, or defective raw
materials. Nonrandom variation causes data points to fall outside control limits or display
unusual patterns, signaling a need for corrective action.
Terms of use
By making use of this document you agree to:
Use this document as a guide for learning, comparison and reference purpose,
Terms of use
Not to duplicate, reproduce and/or misrepresent the contents of this document as your own work,
By making use of this document you agree to:
Use this document
Fully accept the consequences
solely as a guide forshould you plagiarise
learning, reference,or and
misuse this document.
comparison purposes,
Ensure originality of your own work, and fully accept the consequences should you plagiarise or misuse this document.
Comply with all relevant standards, guidelines, regulations, and legislation governing academic and written work.
Disclaimer
Great care has been taken in the preparation of this document; however, the contents are provided "as is" without any express or
implied representations or warranties. The author accepts no responsibility or liability for any actions taken based on the
information contained within this document. This document is intended solely for comparison, research, and reference purposes.
Reproduction, resale, or transmission of any part of this document, in any form or by any means, is strictly prohibited.
, +27 67 171 1739
QUESTION 1
1.1
Random variation (also called common cause variation) refers to the natural,
inherent fluctuations that occur in a process due to countless small, uncontrollable
factors. These variations are expected and typically fall within control limits. For
example, minor differences in temperature or material properties in a manufacturing
process can cause random variation. These do not signal a problem with the
process.
In contrast, nonrandom variation (or special cause variation) arises from identifiable
and controllable sources outside the normal process. These variations are not part
of the system’s natural fluctuation and usually indicate that something has changed
or gone wrong. Examples include equipment malfunction, human error, or defective
raw materials. Nonrandom variation causes data points to fall outside control limits
or display unusual patterns, signaling a need for corrective action.
In summary, random variation is expected and stable, while nonrandom variation is
unusual and requires investigation.
1.2
When using a process control chart, several nonrandom signals can indicate that
the process is out of control:
1. A single point outside the control limits: This is the most obvious signal of
nonrandom variation and suggests a significant shift in the process.
2. A run of seven or more points on one side of the centre line: This may
indicate a gradual drift in the process mean, caused by a systematic issue.
3. A trend of increasing or decreasing points: A continuous upward or
downward pattern suggests that the process is changing over time.
4. Cyclic patterns or regular repeating patterns: These may indicate
external influences such as temperature changes or shift-based performance
issues.
Disclaimer
Great care has been taken in the preparation of this document; however, the contents are provided "as is"
without any express or implied representations or warranties. The author accepts no responsibility or
liability for any actions taken based on the information contained within this document. This document is
intended solely for comparison, research, and reference purposes. Reproduction, resale, or transmission
of any part of this document, in any form or by any means, is strictly prohibited.
