There are 7 basic Quality Control Tools in Quality Management and they are:
1. Control Charts
2. Cause and effect diagram
3. Flowcharting
4. Histogram
5. Pareto Chart
6. Run Chart and
7. Scatter diagram
Control Charts graphically helps one to determine if the process is within acceptable limit. If the Schedule Variance is always within the range, everything is ok. But, if it crosses this limit, you need to investigate and find the reason for the same and take necessary corrective action. Also, if the schedule variance goes out of the limit, it is said to be "Out of Control".
The next Quality Control tool is Cause and Effect Diagram. This is also known as Fishbone Diagram or Ishikawa Diagram. If you look at the picture, it looks like the bone of a Fish and hence the name Fishbone Diagram. Ishikawa is the name of the person who proposed this tool first. That's why its also called Ishikawa diagram. This tool can be used in Quality Planning to look forward to what might contribute to the highest quality on the project. In Quality control it is used backward to identify the root cause of the Problem.
Other quality control tools used:
Flowcharting: Flowchart shows how a process or system flows from beginning to end and how the elements interrelate. Its graphical nature helps in analyzing where the problems occur.
Histogram: It is a vertical bar chart showing how often a particular variable occurred. The height of each column represents the relative frequency of the variable
Pareto Chart : It's also called 80/20 rule. ..Meaning 80% of the problems are because of 20% reasons. It helps focus attention to the most critical issues. In a way, Pareto chart helps identify the critical few from the uncritical many.
Run Chart: Run Chart is used in identifying trend.
Scatter diagram: Tracks two variables to see if they are identified.