Bheemannadora Sappa

Brainstorming is an individual or group method for generating ideas and solutions to problems.
 
Limitations in Brainstorming / How to overcome:
1. The focus on the quantity of ideas can be derailed easily by criticism or poor facilitation. In such case requires an experienced facilitator who is sensitive to group dynamics and social pressures and not afraid to note violations of the ground rules.
2. Group with a large numbers will not effective. In such case use group size 3 - 10, not more than that.
3. Extroverts or the senior people tend to dominate group work. In such case stop the involvement of senior people in the initial brainstorming session.
4. Some participants will not express their ideas “because of the belief that they will be seen as inarticulate or suggest ideas that have little or no values". In such case use brainwriting.  "brainwriting refers to a group of methods that emphasize the silent generation of ideas in writing”
5. Participants social anxiousness or feeling that their ideas will be negatively evaluated by other team members. In such case use nominal group than the interactive brainstorming group.
6. Some participants stay quite during the brainstorm session. In such case use Round Robin method of brainstorming, which allows everyone to pitch in and contribute.
7. The quantity of ideas will suffer when one participant is speaking and blocking the idea generation of the other members. So it is better allow only one group member to speak at a time.

Pre-control charts are the charts made using USL and LSL limits. it is normally preferred VOC. the tolerance between these USL and LSL is divided into two zones, Green and Yellow, Out of tolerance is considered as Red zone.
 
Green is 50% of the tolerance in the center, Yellow is 25%+25% of tolerance to both sides of green.
If the part specification falls either in Green Zone or Yellow Zone, it is acceptable.
If the part specification falls in Red Zone, it is not acceptable.
Pre-control chart with the above limits are printed in paper with color bands and do charting in shop floor.
It helps shop floor operator to control the process so that defective parts are not produced.
 
There are defined rules to qualify the process / setup.
 
How Pre-control charts different from control charts, Advantages:
1. Control chart preferred voice of process, but pre-control charts preferred VOC.
2. Control charts are difficult to understand by shop floor operators, whereas Pre-control charts are simple to understand by shop floor persons.
3. Control charts need sample data and the control limits are derived from the data, whereas Pre-control charts the control limits are Green Zone.
4. Control charts doesn't give the behavior of the process from very beginning, whereas Pre-control charts gives the process behaviour from very beginning.
5. Control charts needs subgroup data to define the control limits, whereas Pre-control charts we are measuring individual measurements.
 
Disadvantages:
1. Pre-control does not concern itself with understanding or estimating process characteristics vital to achieving product quality.
2. Any obvious patterns over time that indicate trends or cycles are not easily detected.
3. Since Pre-control charts uses individual values, it provides little power to detect anything but large process changes. So, pre control chart cannot help detect process change and variation unless drastic.
4. Pre-control is reactionary in nature and does not focus on finding or eliminating the sources of process changes. It leaves it up to the operators to make adjustments to stay within specifications and gives very little attention to eliminating variation at source.