Category 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 Histograms

First introduced by Karl Pearson, an English mathematician and bio-statistician credited with establishing the discipline of mathematical statistics, a histogram is a graph figure which is used to display past data. It differs from the more well-recognized bar graph because a bar graph relates two variables, but a histogram relates only one (i.e., “earnings per month” in our example.

More specifically, histograms represent the distribution of numerical data, providing an estimate of the probability distribution of the continuous variable. Data within a histogram is displayed in “bins” and each bin has the same width. The example above uses $25 as its bin width and shows how many people earned between $800 and $825 per month, $825 and $850 per month, and so on. In other words, the “frequency” of each.

Histograms often provide new insights into the dynamics of process performance by indicating the number of times (frequency) each outcome occurred. Note that the mode of this frequency distribution is between $900 and $925, which occurs some 150 times.

To make a histogram, follow the following simple steps:\

  1. On the vertical axis, place frequencies. Label this axis “Frequency” covering the total span of gathered data points. In the example above, the span ranges from 0 to 200.
  2. On the horizontal axis, place the lower value of each interval measured. In the example above the first “bin” represents earnings between $800 and $825 per month, followed by a bin representing earnings between $825 and $850 per month, and so on.
  3. Draw a bar extending from the lower value of each interval to the lower value of the next interval on the horizontal axis, and reaching up to the associated frequency measurement.

All About Flow Charts

Sample Flow Chart

A simple yet extremely useful improvement tool, a flowchart is a type of diagram that represents a workflow or process. As a graphic depiction or visual map, a flowchart can represent a process with greater clarity than text descriptions alone, thus enabling people to more easily view and follow the “steps.” Consequently, they are very useful when communicating with users or managers about policies, rules, and unnecessary, duplicitous or cumbersome steps within a work process, and help to quickly highlight problems or opportunities for improvement.

When creating a flowchart, process steps are shown as shapes of various kinds, and their order by connecting the shapes with arrows or lines. Different shapes are used to indicate actions, decision points, recycle loops, work and wait times.

Among the most commonly-used shapes are the following:

Common Flow Chart Symbols

Originally, flowcharts were created by hand using pencil and paper. Before the advent of the personal computer, drawing templates made of plastic flowchart shape outlines helped flowchart makers work more quickly and gave their diagrams a more consistent look. Today’s flowcharts are typically created using software.

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.”

All About Fishbone Diagrams

An Ishikawa or fishbone diagram is a visualization tool for categorizing the potential causes of a problem in order to identify its root causes. These diagrams are particularly useful in brainstorming sessions as they help people to focus their conversation.

The technique is named after Dr. Kaoru Ishikawa, a Japanese quality control expert, who invented it to help employees avoid solutions that merely address the symptoms of a much larger problem. The approach begins by stating the problem, and then requires people to identify at least four overall causes or categories that contributed to the problem. Once categories are selected, the team must brainstorm around each cause to further break-down how or why the effect took place.

Because the design of the diagram looks much like a skeleton of a fish, it is commonly referred to as a fishbone diagram.

Common uses of the fishbone diagram range from product design and quality defect prevention to identifying potential factors causing an overall effect or process failure. Each factor or cause for imperfection is a source of variation.

After brainstorming all the possible causes for a problem, users go on to rate the potential causes according to their level of importance and diagram a hierarchy.

Simple Implementation

Fishbone diagrams are typically worked right to left, with each large “bone” of the fish branching out to include smaller bones containing more detail.

  • Create a head, which lists the problem or issue to be studied.
  • Create a backbone for the fish (straight line which leads to the head).
  • Identify at least four “causes” or categories that contribute to the problem. Major categories often include: equipment or supply factors, environmental factors, rules/policy/procedure factors, and people/staff factors. Connect these four causes with arrows to the spine. These will create the first bones of the fish.
  • Brainstorm around each “cause” to document those things that contributed to the cause. Use the 5 Whys or another questioning process such as the 4P’s (Policies, Procedures, People and Plant) to keep the conversation focused.
  • Continue breaking down each cause until the root causes have been identified.

It’s About Time & 5 Steps to Best Measure It

Our previous post shared several reasons as to why the measurement of time is an effective way to identify and eliminate waste.

This approach has consistently proven successful in our work, and some specific examples include:

  • A finance department used this method to reduce reporting cycle time by over 50% by identifying and eliminating the causes of rework.
  • An organization reduced setup times by measuring the time and addressing the causes of the non-value-adding delays.
  • A sales force measured their total time to value-adding time by identifying huge chunks of non-value adding time which they were able to convert to more sales calls.
  • A retirement community studied total housekeeping time relative to value adding time and reduced costs by over 30%.
  • A financial services company studied the total time versus value-adding time for processing time-sensitive transactions and succeeded in simultaneously eliminating both overtime and late
    penalties.

Once you’ve decided that managing time is an ideal way to reduce costs and increase customer (internal and external) satisfaction, you might try using the following five steps for effective measurement:

    1. Identify the process to study and improve: where it starts and where it ends.
    2. Confirm with the customer (internal or external) the key element of value the process yields. Sometimes this is obvious, but in some cases not so much. An accurate understanding of what the customer considers of real value is key to any improvement effort.
    3. Determine how long the process actually takes today. This number— in minutes, hours, days, or weeks, whichever is best suited to the process — is the TOTAL component of the ratio we will calculate in step 5. Some questions often arise at this step:
      • Should we collect “person hours” or elapsed time? Measure elapsed time. If you study and improve elapsed time, you increase customer satisfaction and quality as well as costs. Person hours spent on the work almost always decline when an organization focuses on elapsed time.
      • How precise do we need to be? It is valuable to get good data about the total time elapsed from start to finish, if only through a modest sample. Of course, there will be
        variation — and the variation can be quite substantial for some processes. Keep the raw data, and calculate the average TOTAL.
    4.  Determine which steps actually add value and how much time is spent on those. For a step to be considered to add value, it must:
      • Be directly related to what the customer values and would pay for (if they knew what we were doing)
      • Actually change something of value — the product, database, approval status, whatever, (inspecting something or moving something does not actually change the thing, so does not ‘add value’)
      • Do so for the first and only time. Fixing or reworking something does NOT add value, because it compensates for not being done completely or correctly the first time.
        Often these steps must be done today, because they compensate for an imperfection somewhere in the process. Correcting those imperfections is what will yield the improvements.

      What if we disagree about what is truly adding value? When categorizing work, aim to be as rigorous as possible about applying the criteria for value-added. If you mis-classify a non-value step as adding value, you will lose out on the opportunity to study and possibly eliminate all or part of it. But it is not a fatal mistake; you can always circle back. Once a group has eliminated a first round of waste, they are able to scrutinize what is left more rigorously and find a whole new round of opportunities that may well exceed the first round.

      How precise must we be about the amount of time the specific steps take? Knowledgeable approximations of the individual components that consume time are usually sufficient to
      produce really great improvements.

    5. Study the differences between the total time and the value adding time to identify and eliminate the root causes. Then calculate again. To calculate the ratio: if total time today is 55 hours and value adding time is 2 ½ hours, then the ratio would be either:
      • Total-to-Value: 55 divided by 2.5 = 22, which means that the organization spends 22
        hours for every 1 hour of value add, or
      • Value-To-Total: 2.5 divided by 55 = 4.5%, which means that 4.5% of total elapsed time
        is actually spent adding value.

      It doesn’t matter which you use, as long as you are consistent.

 

Poka-Yokes?

Are you familiar with the term “poka-yoke?”

If so, then you know that a poka-yoke is a specially-designed feature of a process or a product that either prevents common mistakes or
catches them before they cause trouble. Often referred to as “mistake-proofing,” The term comes from the Japanese, meaning “inadvertent error” and “avoidance” and was popularized by the engineer Shingeo Shingo in his crusade to improve quality by eliminating human errors.

We see and use poka-yokes every day. For example, years ago, a dead car battery due to forgetfulness was a common problem. Since then, a poka-yoke was designed to sound a warning bell if the car lights are left on. A “warning” poka-yoke is a big help, but not fool proof. A more powerful poka-yoke has since been built-into newer cars and turns the lights on and off automatically.

Similarly, you see a wire gate swing out of the front of a school bus to guide children safely across the street; you are asked to double-enter a new password to guard against typos; wires are color-coded; highways have rumble strips.

All of these are features of a product or process that were specially designed to reduce the likelihood of a particular human error.

Has your organization created or made effective use of poka-yokes?

If so, we look forward to hearing from you! If not, our next post will focus on how to go about creating poka-yokes.

The 2-Second Rule, and 2 Categories of Visual Management

As the saying goes, “A picture is worth a thousand words!” Thus the value of visual management.

In a recent LinkedIn discussion, it was suggested that to be effective, any attempt at visual management must enable an observer to grasp the situation within two-seconds.

An admirable goal, for sure!

As you are most likely aware, visual management can be a powerful communication tool if, as noted above, it lets people know quickly and effectively exactly the right thing to do in each situation by way of an agreed upon use of signals.

Because visual management highlights the critical information in ways that can’t be ignored, it enables a person to assess the status of the situation at a glance. Consequently, people can get far more done, more quickly, with fewer errors and without the need of additional instruction.

It is also important to recognize that there are two types of visual management tools:

  1. Tools that indicate quickly and reliably what actions to take and not to take in order to maintain process control
  2. Teamwork tools that communicate how a process is performing compared to an agreed upon standard or goal, so the people doing the work easily spot and implement the needed adjustments or improvements

We will take a closer look at each category of visual management in upcoming posts.

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.