Bar Chart/Graph A bar chart is a graph represented by spaced rectangular bars that describe the data points in a set of data. It is usually used to plot discrete and categorical data. The horizontal axis of the chart represents categorical data while the vertical axis of the chart defines discrete data. Although the rectangular bars in a bar chart are mostly placed vertically, they can also be horizontal. Advantages of a Bar Chart • Summarizes a large amount of data in an understandable form. • Easily accessible to a wide audience. Disadvantages of a Bar Chart • It does not reveal key assumptions like causes, effects, patterns, etc. • May require further explanation. Pie Chart A pie chart is a circular graph used to illustrate numerical proportions in a dataset. This graph is usually divided into various sectors, where each sector represents the proportion of a particular numerical element in the set. Uses of Pie Chart • It summarizes data into a visually appealing form. • It is quite simple compared to many graph types. Disadvantages of Pie Chart • It is inapplicable for large datasets. • It cannot visualize groups of data. Pareto Chart A Pareto Chart is a graph that indicates the frequency of defects, as well as their cumulative impact. Pareto Charts are useful to find the defects to prioritize in order to observe the greatest overall improvement. A Pareto Chart is a combination of a bar graph and a line graph. Each bar usually represents a type of defect or problem. The height of the bar represents any important unit of measure — often the frequency of occurrence or cost. Advantages: • One of the essential and most important advantages of Pareto analysis is that it simply helps to identify and determine main cause i.e. root causes of defects or problems. • Defects are firstly ranked in order of their severity i.e. in descending order. Defects are organized from highest to lowest priority with help of Pareto Chart. Defects that are on top with highest priority are eliminated first or resolved first. • With help of Pareto chart, one can also determine cumulative impact of defect. In simple words, cumulative impact is an effect that is being caused due to defect happening over a long period of time. • Pareto Chart also helps and provides a better explanation regarding defects that are needed to resolved first. One can also decide and plan about correct and important measures or actions that are needed to be taken regarding defect. • With help of Pareto chart, skills of individuals are also increased in better ways like problem-solving skills, decision-making skills, etc. It simply helps to improve important skills that are required because when someone prepares a Pareto chart, it enables to organize problems related to defect or anything into cohesive facts. • It also helps in solving issues regarding problem-solving and decision making, time management i.e. be at work on time or personal, change management, etc. • One can plan, analyze, and resolve problems or defects with help of Pareto Chart. Disadvantages: • One of main disadvantages is that root cause analysis cannot be done by itself in Pareto analysis. There is a requirement of tool i.e. root cause analysis tool for determining or identify root causes or major causes of defect. • It does not represent severity of defect or any problem. It only shows qualitative data. • Pareto analysis only focuses on past data where damaged has already happened. Yes, past data is essential too, but it’s not necessary that it will be relevant in future scenarios also. Therefore, it should focus on past data as well as present and future data also. • Pareto analysis cannot be applied to all cases. It is limited to some cases only. • There are other disadvantages also like mistake in scoring problems, mistake in applications, etc. Stem and Leaf Plot A Stem and Leaf Plot is a special table where each data value is split into a "stem" (the first digit or digits) and a "leaf" (usually the last digit). The "stem" values are listed down, and the "leaf" values go right (or left) from the stem values. The "stem" is used to group the scores and each "leaf" shows the individual scores within each group. Advantages of Stem and Leaf Plots It can be used to quickly organize a large list of data values. It is convenient to use in determining median or mode of a data set quickly. Outliers, data clusters, or gaps are easily visible. Disadvantages of Stem and Leaf Plots A stem and leaf plot is not very informative for a small set of data. Time series graph A time series graph is a line graph of repeated measurements taken over regular time intervals. Time is always shown on the horizontal axis. On time series graphs data points are drawn at regular intervals and the points joined, usually with straight lines. Time series graphs help to show trends or patterns.
