<P> In a structures - fabrication and assembly plant in the south - eastern US, some quality circles (QCs) were established by the management (management - initiated); whereas others were formed based on requests of employees (self - initiated). Based on 47 QCs over a three - year period, research showed that management - initiated QCs have fewer members, solve more work - related QC problems, and solve their problems much faster than self - initiated QCS . However, the effect of QC initiation (management - vs. self - initiated) on problem - solving performance disappears after controlling QC size . A high attendance of QC meetings is related to lower number of projects completed and slow speed of performance in management - initiated QCS QCs with high upper - management support (high attendance of QC meetings) solve significantly more problems than those without . Active QCs had lower rate of problem - solving failure, higher attendance rate at QC meetings, and higher net savings of QC projects than inactive QCs . QC membership tends to decrease over the three - year period . Larger QCs have a better chance of survival than smaller QCs . A significant drop in QC membership is a precursor of QC failure . The sudden decline in QC membership represents the final and irreversible stage of the QC's demise . Attributions of quality circles' problem - solving failure vary across participants of QCs: Management, supporting staff, and QC members . </P> <P> There are seven basic quality improvement tools that circles use: </P> <Ul> <Li> Cause - and - effect diagrams (sometimes called Ishikawa or "fishbone" diagrams) </Li> <Li> Pareto charts </Li> <Li> Process mapping, data gathering tools such as check sheets </Li> <Li> Graphical tools such as histograms, frequency diagrams, spot charts and pie charts </Li> <Li> Run charts and control charts </Li> <Li> Scatter plots and correlation analysis </Li> <Li> Flowcharts </Li> </Ul> <Li> Cause - and - effect diagrams (sometimes called Ishikawa or "fishbone" diagrams) </Li>

Who created fishbone diagrams and what are they used for