The N7 and 7 MP Tools

The previous chapter introduced B7: The Seven Basic Tools of Quality. B7 came out of Statistical Process Control (SPC), based on Shewhart's control chart and its subsequent refinements in Japan. Although not all the tools used in SPC are quantitative, SPC as a whole deals with quality issues and characteristics that are more easily quantifiable. But many quality characteristics, especially those related to innovation, customer needs, and product development issues upstream, are not as quantitative. The major portion of the problems that must be solved by managers and staff makes use of worded data.^[1] The seven new tools of QC (N7), developed by the QC Techniques Development Committee of the Union of Japanese Scientists and Engineers (JUSE), were devised to aid in organizing, analyzing, and interpreting qualitative and worded data.^[2], ^[3] JUSE announced the N7 tools in 1977. These tools were subsequently modified and adapted to American industrial practices by Goal/QPC to a similar set of management and planning tools. It called them Seven Management and Planning Tools, and they became known as the 7 MP Tools. They are as follows:^[4], ^[5]

1. Affinity diagram

2. Interrelationship diagraph

3. Tree diagram

4. Prioritization matrices

5. Matrix diagram

6. Process decision program chart (PDPC)

7. Activity network diagram

Although not all the tools in the N7 kit were novel, two things were totally new when introduced:

• These tools have been combined into a cycle of activity that illustrates the output of one tool into the input of a related technique. This creates a continuous flow of analysis that really focuses any planning process.

• The 7 MP tools, which have been used in isolation by planning specialists in the past, are now available to mainstream managers.^[4]

The 7 MP tools are by and large qualitative and preventive; B7 tools, on the other hand, are essentially quantitative and diagnostic. N7 as well as the modified 7 MP tools help you plan for quality, design new products and processes, and reengineer existing ones. This book emphasizes the 7 MP tools, the modified version of the original 7N. These tools, as well as the original N7, work in conjunction with B7, not as their replacement, as the word "new" may imply. B7 and 7 MP tools constitute powerful problem-solving techniques when used in tandem. Table 7.1 summarizes the major differences between B7 and 7 MP tools.

Table 7.1. Differences Between B7 and 7 MP Tools

Category	B7 Tools	7 MP Tools
Problem definition	Define problem after data collection	Define problem before data collection
Basic approach	Analytic	Idea generation, brainstorming, and planning
Typical uses	Data analysis, process control, and continual improvement	New product/process design and reengineering existing ones
Data type	Numeric, hard	Worded, soft
Major capability	Corrective, known/knowable	Preventive, unknown/unknowable
Overall	Quantitative	Qualitative