Once you have selected your project class and estimated PE and TS, you can
use the nomogram to compute the success percentage. Predicting project success
is a delicate art, and the nomogram puts numbers to the various assumptions we
implicitly make about how the various factors influence the outcome. If nothing
else, it provides a unifying framework.
Having used the nomogram to approximate the probability of success, you can
vary TS and PE and do a sensitivity analysis, judging how much you need to elevate
TS or PE or both in order to improve your odds. Replacing lower-performing team
members with better ones, and working to achieve greater teamwork can raise TS.
PE can usually not be improved by tinkering with the process, and changing it
completely in mid-project is almost always catastrophic. On the other hand, any
methodology can be made more effective through assiduous project management. Remember
that the implementation of any process is the key to its effectiveness.
I encourage you to imagine different projects across a wide range of classes,
and to try different team and process combinations. Play with the nomogram to
gain confidence with it. If the results of your trials convince you that it yields
reasonable answers, you will be more inclined to use it in new situations.
Different nomograms can be constructed with different assumptions. For example,
one could choose a project class percentage offset of 5% instead of 10%. Similarly,
the people vs. process ratios could be reduced from 3:1 and 2:1 to only 2:1 and
1.5:1. I deliberately chose large values to test the limits and to produce stark
differences. You may want something a bit more subtle.
Finally, remember that this is an approximation tool. It can only be as good
as the validity of its assumptions and the quality of the input. Results should
be taken with a healthy dose of skepticism, and with the idea that what the nomogram
provides is a starting point for deeper analysis. I'd love it if a PM did the
analysis and came up with 40%, when he thought he had a better-than-even chance
Now the crucial step: If he chucks the whole thing as useless, then we haven't
gotten much for our efforts; our ROI is negative. On the other hand, if he says,
"Sonja Henie's tutu! That's a surprise. Let me check my assumptions about the
project's class, and then have a closer look at PE and TS. Perhaps I have been
too optimistic." That's when the real work begins, work that may in fact increase
the odds that the project is ultimately successful.
I would welcome feedback on the approach and its implementation. Send me an
Email to firstname.lastname@example.org.