With advancement in quality management during the past few years qualitative data analysis has become a new challenge along with quantitative data analysis.
The fundamental tools of quality control; Process flow chart, Check sheet, Histogram, Pareto diagram, Cause and effect diagram, Scatter chart, and Control charts, are well enough capable to analyze the quantitative data and to implement statistical process control. But in case of qualitative data analysis the fundamental QC tools are not sufficient to serve the purpose.
With advent of modern quality tools in the field of quality management the problem of qualitative data analysis reached to the solution. These modern quality tools are known as "New 7 Quality Control Tools"
Basically these tools deal with management and planning of quality control activities like; New product development, Policy deployment, Translating the customer voice into technical requirements, etc. hence these tools are also named as "7 M Tools"
These "New 7 QC Tools" or "7 M Tools" are;
- Affinity Diagram
- Interrelationship Digraph
- Tree Diagram
- Matrix Diagram
- Prioritization Matrices
- Process Decision and Program Chart
- Activity Network Diagram
A brief description of all new 7 tools are given below one by one;
Tool#1: Affinity Diagram
Affinity diagram provides the opportunity of generating a large number of ideas for an issue. Team members brainstorm and collect the ideas as much as possible to solve a problem and paste these ideas on the board to see by all members. Similar type of ideas are then categorized under the same category, and collected in ordered manner for different categories. Similar ideas are under one category.
Tool#2: Interrelationship Digraph
This tool clarifies the interrelationships of many factors of a complex situation. Ideas or issues are placed on paper in circular format. Discuss the issues one by one and find which issue influences others. Draw an arrow between related ideas. An idea from which an arrow coming out is considered as the cause and an idea towards an arrow incoming is considered as the effect.
Count the number of outgoing and incoming arrows for an issue or idea and write under there. The issue having largest number of outgoing arrows is the 'Driver' and the issue having smallest or no incoming arrow is the 'Key Outcome or Effect'.
The tool serve the purpose of root cause analysis when there are many issues or causes available for a problem.
Tool#3: Tree Diagram
When team wants to screwed an idea into lager details, the tree diagram served the purpose. Tree diagram helps in objective achievement by placing the objective in a seed box on extreme left side on the paper then options and means of objective achievement are brainstormed and place horizontally in three different boxes coming out of the seed box, further at next level each new box broken into three new boxes for further details of objective achievement.
Tree diagram grows like fusion reaction.
Tool#4: Matrix Diagram
The objective of construction of matrix diagram is to analyze the correlation between two group of ideas. In-fact matrix diagram is the basic technique used in construction of "Quality Function Deployment or House of Quality (QFD/HOQ). A group of ideas are placed in first row of the matrix say "How's" the customer requirement fulfilled? another group say "What's" are the customer requirements? are placed in first column of the matrix.
Each option in first column is compare the relationship with the corresponding options available in first row of the matrix then place a relationship symbol or numeral in the intersection cell of the matrix for the corresponding row and column option.
Calculate the options importance score and rank accordingly
Tool#5: Prioritization Matrices
This tool prioritize the issues based on weighted criteria using a combination of tree and matrix diagram
First using tree diagram, options of objective achievement are finalized then select the criteria to judge the available options of objective achievement under each criterion.
Prepare a matrix between team members and criteria. Each member then weight the criteria so that all individual criterion weight will equal to 1. Say four team members assign the weights to a criteria as 0.35, 0.15, 0.25, 0.25 then sum of weights is 0.35+0.15+0.25+.025=1.0
Find the sum of each individual criterion score and then prepare a new matrix in which options came from the tree diagram are ranked under each individual criterion and multiply the criterion score. Sum, all the values under the criteria for each option and judge which option should be implemented first.
Tool#6: Process Decision Program Chart
PDPC is used for forecasting the failures that may happen while delivery of the program, like a conference, project presentation, etc. so that the failure could avoid and some countermeasures prepare accordingly.
An objective written on the top of a paper or board, say "Successful execution of a conference". In next step write the means of executing the conference, Next write "What if" i.e. possible failure with probability of failure. Further write the countermeasures to tackle the failure. Write 'o' under those options which are accepted and 'x' which are rejected.
Tool#7: Activity Network Diagram
This tool is also know as Program Review and Evaluation Technique (PERT) or Critical Path Method (CPM). It helps to schedule a project efficiently The tool is from project management.
All tasks are writing on board and arranged in a sequence of their implementation one after another. The time of completion of each task is written under each task. Calculate the Earliest Start and Earliest Finish time. Earliest Finish time can be calculated by adding the task time in Earliest Start time.
Now write the Latest Start and Latest Finish time by moving in reverse direction and find the "Critical Path"
Critical Path is the longest cumulative time of connecting activities when Slack time is zero. Where,
Slack = Latest Start - Earliest Start