The first limit is the upper control limit for values greater than the mean. There are two statistical control limits. The centerline is solid line that represents the mean or the arithmetic average of the measurement of counts. Some control chart also contain specification limit. It also indicates if a process has predictable performance.Įach control chart has a centerline, statistical control limits, and the control data. Control chart is a time oriented diagram that determines if a process is stable or not. The third tool of the seven basic quality control tools is a control chart. The causes are found by looking at the problem statement and asking “Why” until the actionable root cause has been identified or until the reasonable possibilities have been exhausted.įishbone diagrams often prove useful in linking the undesirable effects seen as special variation to the assignable cause upon which project teams should implement corrective actions to eliminate the special variation detected in a control chart. The major categories of potential causes form the structural “bones” and likely causes make up the “ribs”. The “head” of the fishbone carries the problem statement. Fishbone / Ishikawa or why-why diagram is the alternate name for this quality tool. The second tool of the seven basic quality control tools is a cause-and-effect diagram. pareto diagram can often display number of frequencies or consequences of defects collected in check sheets. They are especially useful for gathering attributes data while performing inspections to identify defects. Check sheets organize facts in a manner that facilitate effective collection of useful data on potential quality problems. Tally Sheets or check sheets act as a checklist when gathering data. The first tool of the seven basic quality control tools is a check sheet. Kaoru Ishikawa in 1968 first proposed the seven basic quality tools in his book. The following paragraph enumerates seven basic quality tools Hence this post briefly describes all seven basic quality tools that assist in problem solving and process improvements. Hence this post briefly describes all seven basic quality tools like Pareto chart, Check sheets, Control Charts etc. However, PMBOK 6th edition has grouped all tools and techniques under six distinct categories. PMBOK 5th edition specifically mentioned the complete list of the seven basic quality tools. Seven basic quality tools consist of techniques that facilitate data collection, data analysis and data visualization.