Study Set Content:
a. inexact procedures
b. inadequate procedures
c. negligence by chance
Methods
a. variation of equipment for the same process
b. difference in adjustment of equipment
c. aging and improper care
Machines
a. Changes in temperature and humidity affect various processes.
b. Introduction of particles from outside the clean room can cause variation.
c. Changes in the environment have the ability to trigger changes in raw materials, equipment and human action.
Environment
a. improper working conditions
b. in adequate training and understanding
c. dishonesty, fatigue and carelessness
Men
defined as the use of statistical techniques to control a process or production method.
Statistical Process Control (SPC)
- helps in monitoring the process behavior, discover issues in internal systems, and find solutions for production issues
Statistical Process Control (SPC)
which is intrinsic to the process and will always be present
Common cause variation
which stems from external sources and indicates that the process is out of statistical control
Special cause variation
application of the 14 statistical and analytical tools (7-QC and 7-SUPP) to monitor process outputs (dependent variables).
Statistical Quality Control (SQC)
application of the same 14 tools to control process inputs (independent variables)
Statistical Process Control (SPC)
7 Quality Control (7-QC) Tools made by
Dr. Kaoru Ishikawa - 1974
7 Quality Control (7-QC) Tools
- Cause-and-effect diagram (also called Ishikawa diagram or fishbone diagram)
- Check sheet
- Control chart
- Histogram
- Pareto chart
- Scatter diagram
- Stratification
Supplemental (7-SUPP) Tools
- Data stratification
- Defect maps
- Events logs
- Process flowcharts
- Progress centres
- Randomization
- Sample size determination
- formal organized evaluation process which compares a certain attributes, and dimensions of a product against the standards and specifications this in turn evaluates these variables if they are within the prescribed limits or parameters.
Inspection
- The following are the general process of inspection:
- Interpretation of the specification
- measurement of the product
- Comparison of the product with specification
- Judgment as to conformance
- Disposition of the product
- Recording of the data obtained
is a process of securing a unit that will represent a bulk quantity of materials or population (total of actual items)
Sampling
is a smaller, manageable version of a larger group.
Sample
It is a subset containing the characteristics of a larger population.
Sample
is a detailed outline of which measurements will be taken at what times, on which material, in what manner, and by whom.
Sampling Plan
- working rule regarding size and frequency of sample and the basis for acceptance or rejection
Sampling plan
