The current issue of the National Estimator, The Society of Cost Estimating and Analysis, monthly magazine has an eye opening article titled "Correlating Work Breakdown Structure Elements."
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This should be a frightening fact for all of us who assume no correlation, or worse have no recognition that such correlations are important.
So when the question of "why are projects late and over budget," is asked this is one of the answers, along with a myriad of other answers:
- No understanding of the needed schedule margin, derived from Monte Carlo Simulations
- No understanding of how the increasing maturity of the products or services are being measured in units meaningful to the stakeholders
- No management of the inherent risks of the program
- Insufficient partitioning of work efforts to reduce the coupling between work durations - "How Long Are You Willing to Wait Before You Find Out You're Late?"
- The inability to determine the capacity for work, so all work estimates are underestimated.
- And the final killer result - multitasking creates hidden correlation between WBS elements.
The last element alone, should be reason enough to start to understand the correlations, and remove the multitasking. After that the real correlations, need to be ferreted out and placed in the cost model.