Tag Archives: CI tools

All About Run Charts

Run Charts are simple line graphs of data plotted over time. They are used to better-understand the performance of a process, as they help people distinguish between random variation and special causes, or to track information and predict trends or patterns.

A run chart can also reveal whether a process is stable by looking for a consistent central tendency, variation and randomness of pattern.

One of the most common CI tools, a run chart is easy to interpret and does not require tedious calculations or special software to produce.

Sample Run Chart

How to create a run chart:

    1. Identify the question that the run chart will answer and obtain data that will answer the question over a specified period of time. For example, if you were looking at how long it takes to complete a task, you will make note of the time taken (in minutes) to complete it over a specified period of time.
    2. Gather data, generally collect at least 10 data points to detect meaningful patterns.
    3. Create a graph with vertical line (y axis) and a horizontal line (x axis).
    4. On the vertical line (y axis), draw the scale related to the variable you are measuring. In our example, this would include the complete range of observations measuring time-to-completion
    5. On the horizontal line (x axis), draw the time or sequence scale.
    6. Plot the data, calculate the median and include into the graph.
    7. Interpret the chart. Four simple rules can be used to distinguish between random and non-random variations:
      1. Shift – 6 consecutive points above or below the median
      2. Trend – 5+ consecutive points going up or down
      3. Too many/too few runs – too few or too many crossings of the median line
      4. Astronomical data point – a data point that is clearly different from all others (often a judgement call)

All About Pareto Charts

The Pareto Chart

Simply stated, a Pareto chart is a bar graph that represents problems or opportunities in order of descending magnitude or frequency.

Considered one of the seven key quality and improvement tools, it is named after Vilfredo Pareto, an Italian engineer, sociologist, economist, political scientist, and philosopher. He made several important contributions to economics, particularly in the study of income distribution. He is most well-known for his observation that 80% of the land in Italy was owned by about 20% of the population – now referenced as the “Pareto Principle” or “80/20” rule.

Pareto charts are used for a number of purposes, such as to analyze the frequency of defects in a process, to look at causes in a process, to figure out what the most significant problem in a process is, or to communicate data with others.

Here are seven simple steps for creating a Pareto chart:

  1. Decide what categories you will use to group items
  2. Decide what measurement is appropriate. Common measurements are frequency, quantity, cost and time.
  3. Decide what period of time the Pareto chart will cover: One work cycle? One full day? A week?
  4. Collect the data, recording the category each time, or assemble data that already exist.
  5. Subtotal the measurements for each category.
  6. Determine the appropriate scale for the measurements you have collected. The maximum value will be the largest subtotal from step 5. (If you will do optional steps 8 and 9 below, the maximum value will be the sum of all subtotals from step 5.) Mark the scale on the left side of the chart.
  7. Construct and label bars for each category. Place the tallest at the far left, then the next tallest to its right and so on. If there are many categories with small measurements, they can be grouped as “other.”

10 Key Charting Tools

Continuing our theme of using the “right” tool for the right job, there are some key tools one might use when involved in continuous improvement.

Ultimately, persistent problems cannot be solved by repeatedly using the same knowledge and insights; solutions require the innovative use of multiple problem-solving tools to examine current reality from a variety of different angles.

Here are 10 tools you might consider using:

    1. Pareto Chart

    Pareto Charts contain both bars and a line graph, where individual values are represented in descending order by bars. They are commonly used to explore ideas about possible causes.

  1. Process Mapping is a tool that enables people to spot and quantify the waste and trace it to the primary cause.
  2. Cause and Effect Diagramming is used to stretch beyond initial ideas about possible root causes.
  3. Histograms represent the distribution of numerical data, providing an estimate of the probability distribution of a continuous variable. They provide new insights into the dynamics of process performance.
    1. Run Chart

    Run Charts are line graphs of data plotted over time. They can be used to understand current process performance and distinguish between random variation and special causes.

  4. Scatter Diagrams are primarily used to clarify the importance of possible causal factors on results measurements.
  5. Affinity Diagrams are used to find breakthrough ideas and natural relationships among the data.
  6. Priority Matrices can be used to consider alternatives and identify the right things to work on.
  7. Interrelationship Digraphs provide visual demonstrations of the relationship among factors—causal factors (drivers) vs. symptoms so that you get the most leverage on interventions.
  8. A dependable method of analyzing the data as outlined in recent posts.