Editor's Note | Introduction | Definition of "Success" | The Team
Interaction between Project Class, Process Effectiveness and Team Strength
Commentary on the Nomogram | Conclusion | Editor's Postscript

Commentary on the Nomogram

I would like to draw your attention to the following characteristics of the nomogram.

1. Locate the intersection point with the project success axis, indicated by the vertical arrow near the top of the axes. If you have a "class 3" project, read off the percentage on that axis. If you have one of the other 4 classes, navigate horizontally to the band corresponding to your project class and read off the percentage there. Each step left or right changes the result by 10%.
    
2. You may ask: why are we doing this analysis anyway? If I predict a probability of success of only 53%, should I decide that the risk is too great, and should I cancel the project? Well, that would be one option. But if you can find a way to improve the predicted value by 10%, you go from slightly better than even odds to being an almost two-to-one favorite; the difference between 50% and 67% is huge! So, at 53% and a good project plan, you might start to look for ways to improve PE and TS and have a better shot. You can use the nomogram to do a sensitivity analysis to see the best way to improve. The initial prediction is but a starting point for further analysis.
    
3. We provide two examples on the nomogram for your convenience. They illustrate the interaction of the three variables. In the first example, a class 4 project, we have a PE of 6 and a TS of 4. This is a moderately structured project using a somewhat well-adapted and well-executed process, but with a slightly less than average team.
   
   Referring to the nomogram, we see that since this is a class 4 project, we use second from the right-most vertical scale to locate the value of TS, 4, and the left-most vertical scale to locate PE, 6. Drawing a line to connect them, we find an intersection with the success scale at about 53%. However, this is a class 4 project, so we must move one colored band to the left, into the band that has a 4 at the bottom. Reading the value from that colored band, we obtain a probability of success of about 63%. We would predict that they would be successful a little less than two times out of three.
    
4. On the other hand, consider our second example, a much harder class 1 project. We have a stronger team, TS = 6, and an adequate but slightly weaker process, PE = 5. Using the same methodology, these values yield a success percentage of 45%, so we would expect a favorable outcome slightly less than half the time.
    
5. Note two features. First, project classes have an offset of 10% relative to each other. For a "class 3" project, with a success percentage of 50%, an equivalent combination of PE and TS will yield 60% for class 4 and 70% for class 5. Similarly, they will give 40% for class 2 and only 30% for class 1. In our model, project difficulty has a powerful effect.
   
   Second, PE and TS have different influences depending on class. Note in the example that for a class 4 project, we raise the success percentage more by raising PE than by raising TS by the same amount. This is because for moderately structured projects, process is more important than people, by a factor of two to one. For class 5, the ratio increases to three to one.
   
   On the other hand, for the class 1 project, the success percentage goes up more by increasing TS as opposed to PE; for a very creative project, people are more important than process. For class 3 they have equal effect, for class 2 the ratio is again 2:1, and for class 1, 3:1 as before. Figure 4 summarizes these assumptions.

Figure 4: Summary of sample assumptions

Interaction between Project Class, Process Effectiveness and Team Strength

Conclusion

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