1. MEANING OF SQC
SQC refers to the use of statistical
techniques in controlling the quality
of manufactured goods & achieving
quality specifications which requires
use of tools & techniques of statistics.
2. METHODS of SQC
• 1. PROCESS CONTROL :-
The quality of products is controlled while the
products are in the process of production.
2.PRODUCT CONTROL :-
The quality of products is controlled while the
product is ready for sale & despatch to the
customers
3. CONTROL CHARTS
• The control charts are graphical devices
developed by WALTER A. SHEWHART for
detecting unnatural pattern of variation in the
production process.
• A control chart consists of three horizontal
lines :-
• 1. Central line.
• 2. Upper control limit
• 3. Lower control limit
4. Control Charts Lines/Limits
• Central Line:- It indicates the grand average of
the measurements of the samples. It shows
the desired standard or level of the process.
• Upper Control Limit:- It is usually obtained by
adding 3 sigma to the process average.
• Lower Control Limit:- It is usually obtained by
substracting 3 sigma to the process average.
