Spider Charts: A Training Course This course was developed by Murray S. Pratt, an accounting student at Brigham Young University.

Spider Charts Training Agenda What Are Spider Charts? How Can Your Organization Use Them? Developing Spider Charts Spider Charting Exercise Summary References This is what we will go through during this presentation

What Are Spider Charts? A graphical way to compare data Displayed in a “web-like” form Used to evaluate multiple alternatives based on multiple criteria Spider Charts are also called “Radar Charts”. They are a very useful tool.

How Can Your Organization Use Spider Charts? Do you want to graphically compare multiple potential projects? Do you need to analyze the strengths and weaknesses of different supply chain strategies? Are you finding it difficult to make logical comparisons between business opportunities? If your answer is yes, then Spider Charts may be your solution! Spider Charts are most useful when you have relatively few alternatives (2-4) that you would like to compare based on a few different criteria (3-6). If you have more data to compare, a different method would be more useful.

Developing Spider Charts (Six Easy Steps) Identify the alternatives to be compared Generate criteria to rate each alternative Rate each alternative based on criteria Draw and label the axis arms of the chart (one arm for each criterion) Draw and label each alternative’s ratings on the chart, connecting between arms Analyze the chart These steps are flexible, and can be adjusted to meet your specific needs. However, this basic outline is very useful.

Developing Spider Charts What a Finished Spider Chart Might Look Like: For simplicity’s sake, this spider chart does not have multiple alternatives, only one option is charted. Obviously, the more alternatives compared, the more complicated the chart becomes. For this reason, Spider Charts are most effective for only 2-4 alternatives.

Developing Spider Charts Step 1 – Identify the alternatives to be compared Spider Charts could be used to compare: Potential Projects Performance of Vendors Employee Performance No more than 5 (five) alternatives should be compared using Spider Charts More than five alternatives will usually make the chart confusing. Any alternatives really may be compared.

Developing Spider Charts Step 2 – Generate criteria to rate each alternative Projects can be rated based on risk, return, initial cost, or any other criteria At least three criteria must be used, more may be helpful, but more than seven may be too complex Be creative in thinking up useful criteria on which to evaluate your alternatives.

Developing Spider Charts Step 3 – Rate each alternative based on criteria It is helpful to standardize ratings to some uniform scale (for example 0-10, or 0-100%) It is not necessary to form standardized ratings, however, it is helpful. This will become more clear when we show the examples in this presentation.

Developing Spider Charts Step 4 – Draw and label the axis arms of the chart (one arm for each criterion) If there are five criteria (C) on a scale of 0-10: C-1 10 C-2 C-5 5 The center of the axis arms should always be zero for each arm. Negative values will not work on this type of graph. C-3 C-4

Developing Spider Charts Step 5 – Draw and label each alternative’s ratings on the chart, connecting between arms Using different colors for each alternative is best C-1 10 C-2 C-5 5 You may plot points on each arm and then connect the dots, just don’t mix up which dots belong to which alternative. Alternative 1 Alternative 2 C-3 C-4

Developing Spider Charts Step 6 – Analyze the chart For this example, possible analyses might include: Alternative 1 is better in criterion 1, 2 and 5 Alternative 2 is better in criterion 3 and 4 The largest difference is found in criterion 4 C-1 10 C-2 C-5 5 It is usually most helpful to start with the first criterion, looking at the differences in the alternatives’ values, then move clockwise to each of the other criteria. Then, take a step back and look at the picture as a whole. Notice the shapes of the alternatives’ graphs, and analyze. Alternative 1 Alternative 2 C-3 C-4

Spider Charting Exercise Now, let’s go through an exercise to create a Spider Chart Suppose you want to compare how well three different vendors have delivered goods on time over the past five years. You have the following data: You should try this exercise on your own to make sure you understand how to make a Spider Chart.

Spider Charting Exercise (continued) Data On-time Delivery Percentages Vendors: AppleGate Patriot, Inc. Franklin Year: 1 45% 67% 83% 2 57 64 65 3 68 70 77 4 63 66 91 5 75 71 55 You’ll need this data, so either refer to this slide when solving the problem, or write down this information for your use.

Spider Charting Exercise (continued) Refer to the data on the previous slide and use the Six Steps to create a Spider Chart comparing the three vendors Hint: The “criteria” used in this example are actually the five years The next slide will show the six steps if you need to refer to them.

Spider Charting Exercise (continued) As a reminder, here are the Six Steps: Identify the alternatives to be compared Generate criteria to rate each alternative Rate each alternative based on criteria Draw and label the axis arms of the chart (one arm for each criterion) Draw and label each alternative’s ratings on the chart, connecting between arms Analyze the chart Go through each step. If you get stuck, the next slide gives hints for each of these steps.

Spider Charting Exercise (continued) More hints for the example problem: The alternatives are the three vendors The criteria are the five years The ratings are given as the percentages Your chart should have five arms (for the five years) You should have drawn three “webs”, one for each vendor What does the chart tell you about the vendors? Now you should be able to finish the Spider Chart. The next slide reveals the solution, so don’t look until you have tried.

Spider Charting Exercise Solution Here is what your Spider Chart should look like: Your solution could differ slightly depending on how you arranged the years around the axis.

Spider Charting Exercise Solution This Spider Chart was developed using Microsoft Excel, which is a quick and flexible way to make the chart To make it in MS Excel, input the data in the cells, then “Insert” a “Chart” and select “Radar” as the Chart Type See the last slide for references that will help in MS Excel.

Summary Spider Charts are very useful for visually comparing a few alternatives Just follow the Six Easy Steps to create your own Spider Chart Microsoft Excel provides a quick and easy way to create a Spider Chart That’s it! Spider Charts are really quite simple, but are a very useful and powerful tool.

References (Where to Find More Information) http://www.internet4classrooms.com/excel_radar.htm The Spider Chart: A Unique Tool for Performance Appraisal, 1995, ASQC, Rogers, Cephas B. Go to www.asq.org (the American Society for Quality website) and search for “spider chart” http://www.asq.org/education/docs/radarchart.pdf Beyond Strategic Vision: Effective Corporate Action with Hoshin Planning, Michael Cowley, 199, page 76. The Ultimate Six Sigma: Beyond Quality Excellence, Keki R Bhote, 2001, page 180. The internet sites were active and working as of 11/28/2005, when this was created. Apologies if the sites don’t work when you reference these works. Thanks for viewing this presentation, I hope you found it useful.