11. What are the causes of operator’s errors?
Answer:
1. Incompetence
2. Lack of awareness
3. carelessness and lack of interest
12. What is control charts?
-
A control charts is a graphical
technique in which statistics computed from measured values of a certain
process characteristics are plotted over time to determine if the process
remains in statistical control
-
A control charts is a graphical
technique in which statistics computed from measured values of a certain
process characteristics are plotted over time to determine if the process
remains in statistical control
-
Control charts for variable:
control charts based on upon measurements of quality characteristics are called
as control charts for variables.
13. What is process
capability?
Process capability may be defined as the “minimum spread of a
specific measurement variation which will include 99.7% of the measurement from
the given process”
14. What is defect?
It refers to the failure of quality characteristic to meet the
specified standard.
Types of defect:
Sporadic
Chronic
15. Write the 5 causes of
defects?
1.
Design and specification
2.
Materials
3.
Machinery and equipment
4.
Operating and supervisory staff
5.
Process control and inspection
16. What is defective?
It designates an item which has one or more defects.
17. What is p-chart?
It is also known as fraction defective chart.
18. What is c-chart?
It is used when the number of defects per unit are counted.
19. What is reliability?
The reliability of a product is the probability of performing its
intended function over its specified life.
R (t) = N-n/N
20. Write the factors
affecting reliability?
1.
Complexity of a product
2.
Manufacturing process
3.
Operation and maintenance
4.
Component reliability
5.
Environment conditions
6.
Reliability and failure of a
product
21. What is MTTF?
MTTF stand for Mean Time To Failure. MTTF is the reciprocal of
hazard rate.
22. What is maintainability?
It is defined as the probability that a device will be restored to
its operational effectiveness within the given period, when maintenance action
is performed on accordance with the prescribed procedure.
The maintainability is related to the given maintenance time, if the
given maintenance time is increased the probability of its being restored to
normal function will increase. Since the maintenance time is an important
constraint of maintainability.
23. What is MTBF?
MTBF=MEAN TOME TO FAILURE
Mean time to failure is the men time between successive failures of
a product. It is the ratio of total test time and number of failure during
test.
MTBF= 1/λ=Total test time/number of failure during test
24. What is MTTR?
MTTR= MEAN TIME TO REPAIR
Mean time to repair is thee arithmetic mean of the time required to
perform maintenance action.
