U.S. ATLAS HL-LHC Upgrade Level 2 and Deputies-NSF only Management Mailing List

[Gustaaf Brooijmans <gusbroo AT nevis.columbia.edu>]

Hi George,


> Two points in particular:
> - They think that an upper range on the cost uncertainty of > 50% 
> reflects "a conceptual design maturity level" and suggest that this is 
> not appropriate for a project "approaching final design completion". 
> They think this points to "over-conservatism". We have many items that 
> have an upper range > 50% (namely anything with maturity score > 1.25).

NSF has already told us we should disregard that comment.

> - For task duration uncertainty, they applied uniformly -10% to +15% 
> uncertainty.  That's significantly more optimistic than what we're 
> typically assigning.  (And I don't know what they're doing about 
> correlations, probably ignoring them, decreasing the variance even further.)
>
> Basically they're taking the position that the contingency is driven 
> almost entirely by risk, which is not what we do.

I wouldn't go that far.

> The fact that we get roughly similar conclusions might reflect the fact 
> that, even in our approach, the contribution from risk is significant.

Well, yes, it's ~50%.

Best,

Gustaaf