Quality
control
It is an approach to prevent the
defects rather than detecting the defects.
The ultimate aim of quality control is to provide products which are
dependable, satisfactory and economical
Objectives
of quality control
•Adherence to organization’s quality
policy.
•To decide the std.of quality of a
customer accepted product.
•Preparation of quality plan in accordance
with the stated
objectives.
•Verification of the standards of the
predetermined quality.
•To take different measures to improve the
standard of quality.
•To develop quality consciousness in the
various sections of the
unit.
•To reduce the wastage of the raw
materials, men, money and
material.
Quality
assurance
•Activity
of providing adequate confidence that a
product or service will satisfy given requirement for quality.
Benefits
of quality control
1.Minimum scrap or rework costs
2.Reduced cost of labor
3.Uniform quality and reliability
4.Reduced inspection costs
5.Reduced customer complaints
6.Higher operating efficiency
7.Better utilization of resources
Statistical
Quality Control
•SQC
is the application of statistical techniques to accept or reject products
already produced, or to control the process while it is being carried out.
SQC makes
inspection more reliable and at the same time less costly. Its main objective
is to control the quality of the outgoing products.
Using statistical techniques, SQC collects and analyses data in
assessing and controlling product quality.
SQC
can be broadly divided into 3 categories
- Descriptive
Statistics
- Statistical
Process control
- Acceptance
Sampling
Descriptive
Statistics
•It
is used to describe quality characteristics and relationships. Included are
statistics such as mean, standard deviation and the range etc.
Statistical
Process Control
•Statistical
evaluation of the output of a process during production.
It
involves inspecting a random sample of the output
from a process and deciding whether the
process is producing products with
characteristics that fall within a predetermined range. SPC answers the question of whether the process is functioning properly
or not.
Acceptance
Sampling
•Acceptance
sampling is a process of randomly inspecting a sample of goods and deciding
whether to accept the entire lot based on results.
•Acceptance
sampling determines whether a batch of goods should be accepted or rejected.
Advantages
of SQC
•It
helps in preventing defects from occurring.
•It
also helps in avoidance of risk of accepting a bad lot.
•SQC
avoids inspection of the entire lot.(sample)
•Ensures
maintenance of high standards of quality.