Systems Flashcards
Skibidi (63 cards)
Two aspects of Quality in a Manufactured Product
1) Product Features and 2) Freedom of Deficiencies
What are the product characteristics in Product Features?
- Design Configuration
- Size of Product
- Function and Performance
- Aesthetic appeal
- Ease of use
- Reliability
- Serviceability
What are the product characteristics in Freedom of Deficiencies?
- Absence of defects
- Conformance to specifications
- Components within tolerance
- No missing parts
What is acceptance sampling?
A statistical technique in which a sample drawn from a batch of parts is inspected, and a decision made whether to accept or reject the batch on the basis of the quality of the sample.
What are acceptance sampling applications?
- verifying quality of raw materials
received from a vendor - deciding whether or not to ship a batch of parts or products to a
customer - inspecting parts between steps in a manufacturing sequence
What are the three main objectives of Total Quality Management?
- achieving customer satisfaction
- encouraging involvement of the entire work force
- continuous improvement.
What are the quality control technologies ?
- quality engineering
- quality function deployment
- 100% automated inspection
- on-line inspection
- coordinate measurement
machines for dimensional measurement - noncontact sensors such as machine vision for inspection
What is a Random Process Variations?
Random variations result from intrinsic variability in the process. All processes are characterized by these kinds of variations.
Random variations cannot be avoided; they are caused by factors such as inherent human variability and minor variations in raw materials.
Random variations typically form a normal statistical distribution. This kind of variability continues so long as the
process is operating normally
How about Assignable Process Variations, What’s that? Skibidi
Assignable variations indicate an exception from normal operating conditions. Something has occurred in the process that is not accounted for by random variations.
Reasons for assignable variations include operator mistakes, defective raw materials, tool failures, and equipment malfunctions.
What is meant by the term process capability?
Process capability equals ±3 standard deviations about the mean output value under the assumptions:
(1) the output is normally distributed
(2) steady state operation has been achieved and the process is in statistical control.
What is a control chart?
A control chart is a graphical technique in which statistics computed from measured values of a certain process output characteristic are plotted over time to determine if the process remains
in statistical control.
What does a control chart consists of ?
The chart consists of three horizontal lines that remain constant over time: a center line (CL), a lower control limit (LCL), and an upper control limit (UCL).
The center line is usually set at the nominal design value, and the upper and lower control limits are generally set at ±3
standard deviations of the sample means.
What are the two basic type of control charts?
(1) control charts for variables
(2) control charts for attributes
What does control charts for variables requires?
Measurements of the quality characteristic
of interest.
What does control charts for attributes requires?
A determination of either the fraction of
defects in the sample or the number of defects in the sample
What’s a histogram?
A statistical graph consisting of bars representing different values or ranges
of values.
Length of each bar is proportional to the frequency or relative frequency of
the value or range.
What’s a Pareto chart?
A special form of histogram, in which attribute data are arranged according
to some criteria such as cost or value.
What does a Pareto chart displays?
A graphical display of the tendency for a small proportion of a given population to be more valuable than the much larger majority.
What is a scatter diagram?
An x-y plot of the data taken of two variables of interest.
What is a cause and effect diagram?
A graphical-tabular chart used to list and analyze the potential causes of a given problem
What does a cause and effect diagram also known as?
A fishbone diagram
What does a cause and effect diagram consists of?
A central stem leading to the effect (the problem), with multiple branches coming off the stem listing the various groups of possible causes of the problem.
What is a robust design in Taguchi’s quality engineering?
One in which the function and performance of the product or process are relatively insensitive to variations that are difficult or impossible to control.
What does a robustness means in a product design?
The Product can maintain consistent performance with minimal disturbance due to variations in its operating environment