All the project world a non-linear, non-stationary stochastic process, driven by the exchange of cost, schedule, and technical capabilities - act accordingly
This means:
- No single point estimate can be credible in the absence of knowing the variance on that estimate and knowing something about the underlying statistical uncertainties that drive the probabilistic processes that produce those variances.
- You can not asses the value of something, the decision to make or buy, or the decision to move foreword in search of the business benefit, without knowing the cost of that decision. Both the value and the cost need a probabilistic assessment.
- All decisions must be risk adjusted if they are be be credible. Risk comes from uncertainty. Uncertainty is of two kinds - reducible and irreducible.
- Estimating the impact of your decisions is the role of management. Not estimating, or being unwilling to estimate, the cost, duration, and beneficial outcome of your work efforts is called labor.