When we talk about measuring things in project management, there are four types of outcomes for two attributes of that measurement.
The measurement can be accurate and the measurement can be precision. We want it to be both. But without knowing if it is both, we're probably not going to get what we expected.
This is translated into our estimating processes like this. We need to know the accuracy of the estiimate as well as the precision of that estimate.
It does no good to have a precise estimate, that is not accurate. Or to have an accurate estimate that is not precise. Both are needed, but we also must know if we have accuracy and precise in the presence of natural variability of the underlying processes.
So when someone says I estimate that this project or this part of the project will be $127,700 and take 6 months, you can ask them back accuracy and precision questions.
