vault backup: 2025-12-18 17:14:55
This commit is contained in:
Vendored
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"type": "file",
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"type": "file",
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"ctime": 1761313177282,
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"ctime": 1761313177282,
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"path": "nfpa-70_national-electric-code.md"
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"path": "nfpa-70_national-electric-code.md"
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},
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{
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"type": "file",
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"ctime": 1766074735360,
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"path": "consolidate-estimating-thoughts.md"
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}
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}
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]
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]
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}
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}
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@@ -0,0 +1,64 @@
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---
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||||||
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id:
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aliases: []
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title: "2025-12-18"
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tags:
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- authorship/original
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- destiny/permanent
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- status/draft
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- type/daily
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---
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# 2025-12-18
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## 2025-12-18 08:32
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[[uncertainty-in-construction-estimating]]
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## 2025-12-18 10:38
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#topic/meta
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I definitively think my new approach
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of putting nascent ideas in daily notes
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rather than separate fleeting notes
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is superior.
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The unfortunate reality is I'll never look at most of them again,
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so better that they don't crowd out my main notes.
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## 2025-12-18 14:18
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What interests me most in [[construction-estimating]]
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is an idea you might call "estimating golf":
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the goal is to produce a satisfactory[^1] estimate,
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the estimator can not view the project documents
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and must ask questions about the job
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(answerable in a sentence or less)
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of a neutral party ("the reader").
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The estimator fails if the estimate is unsatisfactory[^1],
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but otherwise is scored by number of questions asked.
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[^1]: satisfactory in terms of accuracy and precision,
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according to the standards of the organization.
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a control estimate must be prepared accordingly
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by a neutral party ("the control").
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You could further imagine different brackets
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for required accuracy and precision,
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whether organization historicals are freely available
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or must be questioned like project details.
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The most interesting part of this problem is choosing when to stop,
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since it requires one to estimate their certainty of their estimate.
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## 2025-12-18 15:22
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PDI has moved up the schedule to transition to Accubid Anywhere
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and will be signing a contract with Trimble in late January.
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[Drawer AI | Automated Electrical Takeoff & Estimating](https://drawer.ai/)
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## 2025-12-18 15:30
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[Kip (unit) - Wikipedia](https://en.wikipedia.org/wiki/Kip_\(unit\))
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[Construction Cost Estimating](https://www.quantity-takeoff.com/index.htm)
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@@ -22,3 +22,5 @@ In this way, projects are better compared to _insurance accounts_.
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* cost of individual service is uncertain
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* cost of individual service is uncertain
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* cost to customer must be minimized
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* cost to customer must be minimized
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![[decrease-in-sigma#^pdf]]
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@@ -13,6 +13,10 @@ tags:
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[actuarial science](https://en.wikipedia.org/wiki/Actuarial_science)
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[actuarial science](https://en.wikipedia.org/wiki/Actuarial_science)
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Divorced from its traditional context of insurance,
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actuarial science is determining the optimal price of a service
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given [[uncertainty|uncertain]] cost.
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## Terms
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## Terms
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* [discounted cash flow](https://en.wikipedia.org/wiki/Discounted_cash_flow)
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* [discounted cash flow](https://en.wikipedia.org/wiki/Discounted_cash_flow)
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@@ -55,7 +55,7 @@ $$
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\Phi : \mathcal{P}([0,\infty)) \to [0,\infty),
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\Phi : \mathcal{P}([0,\infty)) \to [0,\infty),
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$$
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$$
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mapping a cost distribution $\mu_C$ to a scalar.
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mapping a cost distribution $\mu_C$ to a **scalar** (a single value).
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Examples of such functionals include:
|
Examples of such functionals include:
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@@ -4,7 +4,7 @@ aliases: []
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tags:
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tags:
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- authorship/original
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- authorship/original
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- destiny/permanent
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- destiny/permanent
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- occupational/takeoff/standalone-systems
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- occupational/takeoff
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- status/draft
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- status/draft
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- type/guide
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- type/guide
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title: Carbon Monoxide Detection Takeoff
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title: Carbon Monoxide Detection Takeoff
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@@ -30,11 +30,11 @@ Remove estimating-specific content from irrelevant notes.
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Create and use cross-topic notes for complex thoughts:
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Create and use cross-topic notes for complex thoughts:
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* [[uncertainty-in-construction-estimating]]
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* [[actuarial-science-for-construction-estimating]]
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* [[actuarial-science-for-construction-estimating]]
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* [[risk-oriented-estimating]]
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* [[risk-management-for-construction-estimating]]
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* [[risk-management-for-construction-estimating]]
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* [[risk-oriented-estimating]]: resource allocation
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* [[auction-theory-for-construction-estimating]]
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* [[auction-theory-for-construction-estimating]]
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* [[bid-process-strategy]]
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* [[bid-process-strategy]]
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@@ -58,7 +58,6 @@ Create and use cross-topic notes for complex thoughts:
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* [[statistical-modeling-for-construction-estimating]]
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* [[statistical-modeling-for-construction-estimating]]
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* [[transparency-in-construction-estimating]]
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* [[transparency-in-construction-estimating]]
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* [[estimating-ethics]]
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### Orphaned Notes
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### Orphaned Notes
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@@ -0,0 +1,88 @@
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# Decrease in Sigma
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|
```tikz
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|
\usepackage{pgfplots}
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|
\pgfplotsset{compat=1.16}
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|
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|
\begin{document}
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|
\begin{tikzpicture}
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|
\begin{axis}[
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|
width=13cm,
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|
height=7cm,
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|
axis lines=middle,
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|
xlabel={$x$},
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|
ylabel={$\varphi(x;\mu,\sigma)$},
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|
xmin=-6, xmax=6,
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|
ymin=0, ymax=0.85,
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|
samples=400,
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domain=-6:6,
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|
legend style={draw=none, fill=none, at={(0.98,0.98)}, anchor=north east},
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legend cell align=left,
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ytick=\empty,
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]
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|
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|
% Normal PDF: (1/(sigma*sqrt(2*pi))) * exp(-(x-mu)^2/(2*sigma^2))
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\addplot[thick]
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{ (1/(1.8*sqrt(2*pi))) * exp(-((x-0.8)^2)/(2*1.8^2)) };
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\addlegendentry{$\mu=0,\ \sigma=1.8$}
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|
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|
\addplot[thick, dashed]
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{ (1/(0.8*sqrt(2*pi))) * exp(-((x-0.8)^2)/(2*0.8^2)) };
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|
\addlegendentry{$\mu=0,\ \sigma=0.8$}
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|
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|
\end{axis}
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\end{tikzpicture}
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\end{document}
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|
```
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|
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|
^pdf
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|
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|
```tikz
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|
\usepackage{pgfplots}
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|
\pgfplotsset{compat=1.16}
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|
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|
\pgfmathdeclarefunction{erfapprox}{1}{%
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|
\pgfmathparse{%
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|
% save sign and work with |x|
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|
( (#1<0) ? -1 : 1 )
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|
* ( 1 - (1 + 0.278393*abs(#1) + 0.230389*abs(#1)^2 + 0.000972*abs(#1)^3 + 0.078108*abs(#1)^4)^(-4) )
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|
}%
|
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|
}
|
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|
|
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|
% Normal CDF using erf approximation:
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|
% F(x;mu,sigma) = 0.5*(1 + erf((x-mu)/(sigma*sqrt(2))))
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|
\pgfmathdeclarefunction{normcdf}{3}{%
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|
\pgfmathparse{ 0.5*(1 + erfapprox((#1-#2)/(#3*sqrt(2)))) }%
|
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|
}
|
||||||
|
|
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|
\begin{document}
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||||||
|
\begin{tikzpicture}
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||||||
|
\begin{axis}[
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|
width=13cm,
|
||||||
|
height=7cm,
|
||||||
|
axis lines=middle,
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|
xlabel={$x$},
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||||||
|
ylabel={$F(x;\mu,\sigma)$},
|
||||||
|
xmin=-6, xmax=6,
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||||||
|
ymin=0, ymax=1.05,
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|
samples=400,
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|
domain=-6:6,
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|
legend style={draw=none, fill=none, at={(0.02,0.98)}, anchor=north west},
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|
legend cell align=left,
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|
ytick={0,0.5,1},
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|
]
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|
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|
% Normal CDF: 0.5*(1 + erf((x-mu)/(sigma*sqrt(2))))
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\addplot[thick]
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{ normcdf(x,0,1.8) };
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|
\addlegendentry{$\mu=0,\ \sigma=1.8$}
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|
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|
\addplot[thick, dashed]
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{ normcdf(x,0.8) };
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|
\addlegendentry{$\mu=0,\ \sigma=0.8$}
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|
|
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|
\end{axis}
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|
\end{tikzpicture}
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|
\end{document}
|
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|
```
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@@ -5,7 +5,7 @@ aliases:
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|||||||
tags:
|
tags:
|
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- authorship/original
|
- authorship/original
|
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- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/standalone-systems
|
- occupational/takeoff
|
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- status/draft
|
- status/draft
|
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- type/guide
|
- type/guide
|
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title: Distributed Antenna Systems (DAS) Takeoff
|
title: Distributed Antenna Systems (DAS) Takeoff
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@@ -22,17 +22,19 @@ title: Distributed Antenna Systems (DAS) Takeoff
|
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> [!info] Cellular Systems
|
> [!info] Cellular Systems
|
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> Less common than ERRCS are "cellular DAS" systems
|
> Less common than ERRCS are "cellular DAS" systems
|
||||||
|
|
||||||
|
`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/...
|
||||||
|
|
||||||
## Backbone
|
## Backbone
|
||||||
|
|
||||||
### FACR to Every Elevator Shaft
|
### FACR to Every Elevator Shaft
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`FACR TO ELEV PIT = ...`
|
1. .../`FACR TO ELEV PIT = ...`
|
||||||
* **Length** = _Match Fire Alarm takeoff Length_
|
* **Length** = _Match Fire Alarm takeoff Length_
|
||||||
* **Count** = _Match Fire Alarm takeoff Count_
|
* **Count** = _Match Fire Alarm takeoff Count_
|
||||||
|
|
||||||
### FACR to Every Staircase
|
### FACR to Every Staircase
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`FACR TO STAIRWELL = ...`
|
1. .../`FACR TO STAIRWELL = ...`
|
||||||
* **Length** = _Match Fire Alarm takeoff Length_
|
* **Length** = _Match Fire Alarm takeoff Length_
|
||||||
* **Count** = _Match Fire Alarm takeoff Count_
|
* **Count** = _Match Fire Alarm takeoff Count_
|
||||||
|
|
||||||
@@ -40,22 +42,22 @@ title: Distributed Antenna Systems (DAS) Takeoff
|
|||||||
|
|
||||||
1. * `Area` = "Typical - Stairwells Building Even Levels"
|
1. * `Area` = "Typical - Stairwells Building Even Levels"
|
||||||
|
|
||||||
`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`STAIRWELL RISER EVERY 2 FLRS = ...`
|
.../`STAIRWELL RISER EVERY 2 FLRS = ...`
|
||||||
* **Count** = Each stairwell
|
* **Count** = Each stairwell
|
||||||
|
|
||||||
### FACR to Electric Room
|
### FACR to Electric Room
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`FACR TO 2HR-RATED RM = ...`
|
1. .../`FACR TO 2HR-RATED RM = ...`
|
||||||
* **Length** = _Match Fire Alarm takeoff Length_
|
* **Length** = _Match Fire Alarm Terminal Cabinet takeoff Length_
|
||||||
|
|
||||||
### Electric Room Riser to Every Floor
|
### Electric Room Riser to Every Floor
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`2HR-RATED RM RISER TO EVERY FLR = ...`
|
1. .../`2HR-RATED RM RISER TO EVERY FLR = ...`
|
||||||
* **Count** = Each Electric Room
|
* **Count** = Each Electric Room
|
||||||
|
|
||||||
### Top 2H Rated Room To Roof
|
### Top 2H Rated Room To Roof
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`TOP 2HR RATED RM TO ROOF = ...`
|
1. .../`TOP 2HR RATED RM TO ROOF = ...`
|
||||||
* **Length** = Top level ceiling height to structure (minimum 15ft)
|
* **Length** = Top level ceiling height to structure (minimum 15ft)
|
||||||
|
|
||||||
## Horizontal
|
## Horizontal
|
||||||
@@ -64,5 +66,5 @@ title: Distributed Antenna Systems (DAS) Takeoff
|
|||||||
> Usually only for cellular DAS.
|
> Usually only for cellular DAS.
|
||||||
> Confirm takeoff requirement with [[pdi-estimating#Bid Estimating|Bid]].
|
> Confirm takeoff requirement with [[pdi-estimating#Bid Estimating|Bid]].
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`CORRIDORS ...`
|
1. .../`CORRIDORS ...`
|
||||||
* **Length** = Length measured for every corridor/garage
|
* **Length** = Length measured for every corridor/garage
|
||||||
|
|||||||
@@ -5,7 +5,7 @@ title: Electrical Takeoff
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/electrical
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
---
|
---
|
||||||
|
|||||||
@@ -16,6 +16,8 @@ title: Emergency Systems Research
|
|||||||
> * [[two-way-takeoff]]
|
> * [[two-way-takeoff]]
|
||||||
> * [[distributed-antenna-systems-takeoff]]
|
> * [[distributed-antenna-systems-takeoff]]
|
||||||
|
|
||||||
|
[[wiring-method-selection]]
|
||||||
|
|
||||||
1. Find Fire Alarm plans (if present)
|
1. Find Fire Alarm plans (if present)
|
||||||
2. Locate the following rooms:
|
2. Locate the following rooms:
|
||||||
* Fire Command Center (FCC)
|
* Fire Command Center (FCC)
|
||||||
|
|||||||
+1
-1
@@ -4,7 +4,7 @@ aliases: []
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/feeders
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Feeders Takeoff
|
title: Feeders Takeoff
|
||||||
|
|||||||
+36
-30
@@ -1,13 +1,13 @@
|
|||||||
---
|
---
|
||||||
id:
|
id:
|
||||||
aliases: []
|
aliases: []
|
||||||
|
title: Fire Alarm Takeoff
|
||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/fire-alarm
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Fire Alarm Takeoff
|
|
||||||
---
|
---
|
||||||
# Fire Alarm Takeoff
|
# Fire Alarm Takeoff
|
||||||
|
|
||||||
@@ -28,46 +28,58 @@ _Mid Rise, High Density (Wood frame):_ Free air, conduit only where required.
|
|||||||
|
|
||||||
## Backbone
|
## Backbone
|
||||||
|
|
||||||
Put all backbone takeoff in the `Area` of the Fire Command Center.
|
|
||||||
Include [[sleeving-takeoff]] as necessary.
|
Include [[sleeving-takeoff]] as necessary.
|
||||||
|
|
||||||
|
`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/...
|
||||||
|
|
||||||
### Fire Command Center
|
### Fire Command Center
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`HEAD END EQUIP`/`... HEAD END`
|
1. * `Area` = As shown.
|
||||||
|
* `Phase` = As shown.
|
||||||
|
|
||||||
|
.../`HEAD END EQUIP`/`... HEAD END`
|
||||||
|
|
||||||
### Generator Room
|
### Generator Room
|
||||||
|
|
||||||
1. `Area` = Same as FACR
|
1. * `Area` = Same as FACR.
|
||||||
|
* `Phase` = Same as FACR.
|
||||||
|
|
||||||
`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`GENERATOR ROOM ...`
|
.../`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`GENERATOR ROOM ...`
|
||||||
|
|
||||||
### Fire Pump Room
|
### Fire Pump Room
|
||||||
|
|
||||||
1. `Area` = Same as FACR
|
1. * `Area` = Same as FACR.
|
||||||
|
* `Phase` = Same as FACR.
|
||||||
|
|
||||||
`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`FIRE PUMP ROOM ...`
|
.../`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`FIRE PUMP ROOM ...`
|
||||||
|
|
||||||
### Elevator Control Rooms
|
### Elevator Control Rooms
|
||||||
|
|
||||||
> Also "Elevator Machine Room"
|
> Also "Elevator Machine Room"
|
||||||
|
|
||||||
|
* `Area` = Same as FACR.
|
||||||
|
* `Phase` = Same as FACR.
|
||||||
|
|
||||||
For each Elevator Control Room (ECR):
|
For each Elevator Control Room (ECR):
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`ELEV CONTROL ROOM ...`
|
1. .../`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`ELEV CONTROL ROOM ...`
|
||||||
* **Count** = 1
|
* **Count** = 1
|
||||||
|
|
||||||
2. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`FACR TO ELEV CONTROL RM ...`
|
2. .../`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`FACR TO ELEV CONTROL RM ...`
|
||||||
* **Length** = Length measured from the most distant points of the FACR and ECR.
|
* **Length** = Length measured from the most distant points of the FACR and ECR.
|
||||||
* Input adder length to reach the level of the ECR (Minimum 15ft).
|
* Input adder length to reach the level of the ECR (Minimum 15ft).
|
||||||
|
|
||||||
### Elevator Shafts
|
### Elevator Shafts
|
||||||
|
|
||||||
|
* `Area` = Same as FACR.
|
||||||
|
* `Phase` = Same as FACR.
|
||||||
|
|
||||||
For each elevator shaft:
|
For each elevator shaft:
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`ELEV SHAFT ...`
|
1. .../`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`ELEV SHAFT ...`
|
||||||
* **Count** = 1
|
* **Count** = 1
|
||||||
|
|
||||||
2. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`FACR TO ELEV SHAFT ...`
|
2. .../`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`FACR TO ELEV SHAFT ...`
|
||||||
* **Length** = Length measured from the most distant points of the FACR and elevator shaft.
|
* **Length** = Length measured from the most distant points of the FACR and elevator shaft.
|
||||||
* Input adder length to reach the level of the shaft (Minimum 15ft).
|
* Input adder length to reach the level of the shaft (Minimum 15ft).
|
||||||
|
|
||||||
@@ -91,7 +103,10 @@ For each elevator shaft:
|
|||||||
|
|
||||||
For each stairwell:
|
For each stairwell:
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`FACR TO STAIRWELLS 1" CONDUIT ...`
|
1. * `Area` = Same as FACR.
|
||||||
|
* `Phase` = Same as FACR.
|
||||||
|
|
||||||
|
.../`GEN, ELEV, FIRE PUMP & FA ROOM ASSEMBLIES`/`FACR TO STAIRWELLS 1" CONDUIT ...`
|
||||||
* **Length** = Length measured from the most distant points of the FACR and stairwell.
|
* **Length** = Length measured from the most distant points of the FACR and stairwell.
|
||||||
* Input adder length to reach the level of the stairwell (Minimum 15ft).
|
* Input adder length to reach the level of the stairwell (Minimum 15ft).
|
||||||
|
|
||||||
@@ -104,7 +119,7 @@ For each stairwell:
|
|||||||
|
|
||||||
1. Horizontal:
|
1. Horizontal:
|
||||||
|
|
||||||
* `Area` = Same as FACR
|
* `Area` = Same as FACR.
|
||||||
|
|
||||||
`... HORIZONTAL RUN`
|
`... HORIZONTAL RUN`
|
||||||
* **Length** = Length measured from FACR to all electrical rooms
|
* **Length** = Length measured from FACR to all electrical rooms
|
||||||
@@ -141,31 +156,22 @@ For each stairwell:
|
|||||||
### Smoke Detectors
|
### Smoke Detectors
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`INITIATING DEVICES WITH WIRE - ...`/`SMOKE DETECTOR W/ BASE - ...`
|
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`INITIATING DEVICES WITH WIRE - ...`/`SMOKE DETECTOR W/ BASE - ...`
|
||||||
|
* **Count:** As shown, otherwise (1) every stairwell at every level.
|
||||||
_Design Build:_
|
|
||||||
Count every stairwell at every level.
|
|
||||||
|
|
||||||
### Pull Stations
|
### Pull Stations
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`INITIATING DEVICES WITH WIRE - ...`/`PULL STATION - ...`
|
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`INITIATING DEVICES WITH WIRE - ...`/`PULL STATION - ...`
|
||||||
|
* **Count:** As shown, otherwise (1) every stairwell at every level and every exterior exit.
|
||||||
_Design Build:_
|
|
||||||
Count every stairwell at every level
|
|
||||||
and every exterior exit.
|
|
||||||
|
|
||||||
### Flow/Tamper Switches
|
### Flow/Tamper Switches
|
||||||
|
|
||||||
No free-air. If wood frame, take off as EMT.
|
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`INITIATING DEVICES ...`/`ADDRESSABLE DUAL MONITOR MODULE - FLOW/TAMPER - ...` (No free-air)
|
||||||
|
* **Count:** As shown, otherwise (1) every stairwell at every level.
|
||||||
_Design Build:_
|
|
||||||
Count every stairwell at every level.
|
|
||||||
|
|
||||||
### Magnetic Door Holders
|
### Magnetic Door Holders
|
||||||
|
|
||||||
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`INDICATING DEVICES WITH WIRE - ...`/`MAGNETIC DOOR HOLDER - ...`
|
1. `COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`INDICATING DEVICES WITH WIRE - ...`/`MAGNETIC DOOR HOLDER - ...`
|
||||||
|
* **Count:** As shown, otherwise (2) every set of double doors.
|
||||||
_Design Build:_
|
|
||||||
Count 2 for every set of double doors.
|
|
||||||
(Typical of elevator lobbies and corridors)
|
(Typical of elevator lobbies and corridors)
|
||||||
|
|
||||||
### Horns, Speakers, and Strobes
|
### Horns, Speakers, and Strobes
|
||||||
@@ -177,8 +183,8 @@ _Design Build (method 1):_
|
|||||||
* measure with circles on Bluebeam
|
* measure with circles on Bluebeam
|
||||||
* or divide relevant SF area by 4415
|
* or divide relevant SF area by 4415
|
||||||
* $\pi(\frac{75}{2})^2 \approx 4415$
|
* $\pi(\frac{75}{2})^2 \approx 4415$
|
||||||
* every elevator lobby,
|
* every elevator lobby, and
|
||||||
* and every BOH room on the first floor and garage levels.
|
* every BOH room on the first floor and garage levels.
|
||||||
|
|
||||||
_Design Build (alternative method):_
|
_Design Build (alternative method):_
|
||||||
* 15ft from end of corridor,
|
* 15ft from end of corridor,
|
||||||
|
|||||||
@@ -4,7 +4,7 @@ aliases: []
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/electrical
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Fire Resistive Wiring Methods Takeoff
|
title: Fire Resistive Wiring Methods Takeoff
|
||||||
|
|||||||
@@ -4,7 +4,7 @@ aliases: []
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/fixtures
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Fixture Designations
|
title: Fixture Designations
|
||||||
|
|||||||
+1
-1
@@ -4,7 +4,7 @@ aliases: []
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/fixtures
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Fixtures Takeoff
|
title: Fixtures Takeoff
|
||||||
|
|||||||
@@ -5,7 +5,7 @@ title: Grounding Takeoff
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/feeders
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
---
|
---
|
||||||
|
|||||||
@@ -4,7 +4,7 @@ aliases: []
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/electrical
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Lighting Controls Takeoff
|
title: Lighting Controls Takeoff
|
||||||
|
|||||||
@@ -3,7 +3,7 @@ id:
|
|||||||
aliases: []
|
aliases: []
|
||||||
tags:
|
tags:
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/lightning-protection
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
- authorship/original
|
- authorship/original
|
||||||
|
|||||||
@@ -4,7 +4,7 @@ aliases: []
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/low-voltage
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Low Voltage Takeoff
|
title: Low Voltage Takeoff
|
||||||
|
|||||||
@@ -12,3 +12,4 @@ tags:
|
|||||||
# Me-isms
|
# Me-isms
|
||||||
|
|
||||||
* (when misunderstood) "No, no, no."
|
* (when misunderstood) "No, no, no."
|
||||||
|
* certainly
|
||||||
|
|||||||
@@ -15,84 +15,15 @@ tags:
|
|||||||
|
|
||||||
Cross-topic of [[risk-management]] and [[construction-estimating]].
|
Cross-topic of [[risk-management]] and [[construction-estimating]].
|
||||||
|
|
||||||
## Prioritizing Tasks
|
## Estimating as Risk Mitigation
|
||||||
|
|
||||||
ROE prioritizes estimating tasks by their contribution to _cost certainty_.
|
|
||||||
|
|
||||||
### Estimating as Risk Mitigation
|
|
||||||
|
|
||||||
* reduce risk of wasted estimation effort due to bid loss
|
* reduce risk of wasted estimation effort due to bid loss
|
||||||
(prefer lower bid)
|
(prefer lower bid)
|
||||||
* reduce risk of project overrun
|
* reduce risk of project overrun
|
||||||
(prefer higher bid)
|
(prefer higher bid)
|
||||||
|
|
||||||
Estimating resources are allocated by Return on Mitigation (RoM)
|
Estimating resources should be allocated
|
||||||
|
according to Return on Mitigation (RoM),
|
||||||
|
that is, their contribution to _cost certainty_.
|
||||||
|
|
||||||
### Determining Necessary Detail
|
$\text{Efficiency} = -1 \times \frac{d\sigma}{dt}$
|
||||||
|
|
||||||
ROE determines the appropriate level of [[estimating-detail]]
|
|
||||||
given an organization's [[risk#Risk Tolerance]].
|
|
||||||
|
|
||||||
#### EVI Takeoff
|
|
||||||
|
|
||||||
Expected value of information (EVI)
|
|
||||||
|
|
||||||
#### Takeoff Optimization
|
|
||||||
|
|
||||||
For systems where EVI analysis determines manual takeoff is still necessary,
|
|
||||||
optimizations can be made to decrease the required effort of takeoff,
|
|
||||||
and thus the opportunity cost of takeoff.
|
|
||||||
|
|
||||||
See [[optimal-estimating-patterns]] for more.
|
|
||||||
|
|
||||||
# Estimating Detail
|
|
||||||
|
|
||||||
The acceptable level of detail of an estimate
|
|
||||||
in [[construction-estimating]] is a contentious subject.
|
|
||||||
What's worse, estimators often disagree
|
|
||||||
on what makes an estimate more detailed than another.
|
|
||||||
|
|
||||||
The commonly repeated answer is this:
|
|
||||||
|
|
||||||
> As detailed as possible,
|
|
||||||
> given required turnaround and available estimating resources.
|
|
||||||
|
|
||||||
This analysis is flawed
|
|
||||||
because it implies more time always ought to be preferred,
|
|
||||||
when the reality is that when considering larger organizational factors,
|
|
||||||
ideal estimate certainty is likely far lower than most expect.
|
|
||||||
|
|
||||||
The correct answer involves optimizing for these factors:
|
|
||||||
* value of increased bid certainty
|
|
||||||
* value of increased estimate volume
|
|
||||||
|
|
||||||
An estimate's detail is irrelevant to its quality.
|
|
||||||
A less detailed estimate is a more [[risk|risky]] bid,
|
|
||||||
but it is not the role of the estimator to determine acceptable risk.
|
|
||||||
|
|
||||||
## Experiment
|
|
||||||
|
|
||||||
Perform a system takeoff (lighting for example) in exacting detail,
|
|
||||||
the maximum amount you would ever consider using,
|
|
||||||
and measure the time required to do so,
|
|
||||||
as well as the cost of the scope.
|
|
||||||
|
|
||||||
Have another estimator takeoff the same scope
|
|
||||||
using the proposed time saving strategy.
|
|
||||||
|
|
||||||
Repeat the test on additional projects.
|
|
||||||
|
|
||||||
Treat the detailed takeoff as the true value
|
|
||||||
and find the error of the time saving strategy.
|
|
||||||
|
|
||||||
$\frac{d\sigma}{dt}$
|
|
||||||
|
|
||||||
### Expectation
|
|
||||||
|
|
||||||
Time-saving strategies will overestimate or underestimate detailed takeoff
|
|
||||||
depending on the assumptions used in their creation.
|
|
||||||
|
|
||||||
## Human Error
|
|
||||||
|
|
||||||
It is commonly understood that a "detailed takeoff"
|
|
||||||
is more "accurate" than a square foot estimate.
|
|
||||||
|
|||||||
@@ -1,120 +0,0 @@
|
|||||||
---
|
|
||||||
id: risk-oriented-estimating
|
|
||||||
aliases: []
|
|
||||||
tags:
|
|
||||||
- destiny/fleeting
|
|
||||||
- status/incomplete
|
|
||||||
- topic/estimating
|
|
||||||
- topic/risk
|
|
||||||
- type/supertopic
|
|
||||||
- authorship/original
|
|
||||||
title: Risk Oriented Estimating
|
|
||||||
---
|
|
||||||
# Risk Oriented Estimating
|
|
||||||
|
|
||||||
## Abstract
|
|
||||||
|
|
||||||
Risk-Oriented Estimating (ROE),
|
|
||||||
is a [[estimating-methodologies|methodology]]
|
|
||||||
for [[construction-estimating]] which:
|
|
||||||
* prioritizes estimating tasks,
|
|
||||||
* determines necessary [[estimating-detail]]
|
|
||||||
|
|
||||||
ROE leans heavily on [[uncertainty#Value of Information]],
|
|
||||||
which challenges the natural tendency to fear even the smallest risk
|
|
||||||
with the reality of the **cost of certainty**.
|
|
||||||
|
|
||||||
ROE does not endorse common shortcuts that round up to "cover" uncertainty,
|
|
||||||
as these ultimately _increase_ risk by inflating the apparent project cost,
|
|
||||||
increasing the probability of loss to a competitor.
|
|
||||||
|
|
||||||
%%
|
|
||||||
|
|
||||||
## TALK
|
|
||||||
|
|
||||||
This note currently gets too far into the weeds
|
|
||||||
of critiquing common practice.
|
|
||||||
|
|
||||||
%%
|
|
||||||
|
|
||||||
## Potential Objections
|
|
||||||
|
|
||||||
Objections to the use of historical data in new estimates are not unfounded.
|
|
||||||
A framework to do so competently and consistently
|
|
||||||
does not currently exist.
|
|
||||||
Nor does the software necessary to utilize such a framework efficiently.
|
|
||||||
|
|
||||||
The goal in and of itself ought not be controversial, however.
|
|
||||||
Businesses regularly make far riskier decisions based on projections
|
|
||||||
informed by the same data.
|
|
||||||
|
|
||||||
By definition, if one could adjust historical pricing accurately for all dependent factors,
|
|
||||||
the adjusted price would be accurate to the new job.
|
|
||||||
|
|
||||||
The issue is that there are hundreds to thousands of potential dependent factors.
|
|
||||||
A nonstarter for uncreative minds,
|
|
||||||
but a worthwhile challenge for estimators truly passionate about their field.
|
|
||||||
|
|
||||||
It is unique of construction estimating among similar fields
|
|
||||||
that analysis and discussion of risk is largely absent from pre-approval review.
|
|
||||||
The tools common of our trade almost always lack the means
|
|
||||||
to quantify the dollar amount implications of our assumptions.
|
|
||||||
|
|
||||||
There is an enormous gap in complexity between pure square foot pricing and
|
|
||||||
[[traditional-estimating-methods]] that tools do not exist to bridge.
|
|
||||||
|
|
||||||
At all points in the estimating process,
|
|
||||||
It should be possible to give a confident budget.
|
|
||||||
|
|
||||||
## In Comparison
|
|
||||||
|
|
||||||
For most contractors, there is not usually a minimum amount of project detail
|
|
||||||
required to provide a budget for a project
|
|
||||||
Estimators know what the most likely and most expensive options are for a given scope
|
|
||||||
and can fill in the detail required for item-oriented takeoff.
|
|
||||||
This is called an **assumption** and is the basis of cost estimation.
|
|
||||||
|
|
||||||
Assumptions are fundamentally incompatible with item-oriented estimating
|
|
||||||
as it is commonly implemented.
|
|
||||||
It is not possible to compare price possibilities
|
|
||||||
except by creating separate takeoffs and breakdowns for each one.
|
|
||||||
|
|
||||||
Rather than building the job one `WOOD NAIL - GALV STEEL - #10 - 5-INCH` at a time,
|
|
||||||
risk-oriented estimating focuses on reducing risk of a decent budget.
|
|
||||||
|
|
||||||
Risk-oriented estimating understands a `NAIL` like an estimator:
|
|
||||||
an abstract item in a certain price range requiring labor in a certain hour range.
|
|
||||||
|
|
||||||
A practitioner of this style would find
|
|
||||||
that the impact of such details on the final price of a job
|
|
||||||
are so low as to be trivial.
|
|
||||||
Not to say that they shouldn't be addressed,
|
|
||||||
only that they ought not be addressed before more significant factors.
|
|
||||||
|
|
||||||
Risk is a measure of the effect of uncertainty on outcome.
|
|
||||||
Uncertainty being a necessity of estimating,
|
|
||||||
the language and tools that we use
|
|
||||||
must facilitate discussions of risk management.
|
|
||||||
In estimation in fields other than construction
|
|
||||||
it is common to give an estimate as a _confidence interval_,
|
|
||||||
a range in which a result has a certain percentage chance to fall.
|
|
||||||
This interval can be determined from a population of possible prices.
|
|
||||||
|
|
||||||
The _accuracy_ of a risk-oriented estimate remains roughly the same
|
|
||||||
(approaching 100% with continuous input)
|
|
||||||
through the takeoff process, and---assuming no incorrect input---
|
|
||||||
is entirely out of the hands of the estimator doing the "takeoff".
|
|
||||||
Other notes describe how a centralized system
|
|
||||||
separates the concerns of adjustment factors
|
|
||||||
and data input for individual projects.
|
|
||||||
|
|
||||||
The "takeoff" workflow then is not about progressively approaching the target
|
|
||||||
price as with item-oriented methods,
|
|
||||||
but reducing the range of possible target prices,
|
|
||||||
reducing the risk of the estimate.
|
|
||||||
|
|
||||||
Abandoning an item-oriented estimate
|
|
||||||
at any point before 100% completion
|
|
||||||
results in effectively 100% wasted effort.
|
|
||||||
In contrast, an abandoned risk-oriented estimate
|
|
||||||
becomes a budget with no additional effort.
|
|
||||||
@@ -3,7 +3,7 @@ id:
|
|||||||
aliases: []
|
aliases: []
|
||||||
tags:
|
tags:
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/standalone-systems
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
- authorship/original
|
- authorship/original
|
||||||
|
|||||||
@@ -15,6 +15,22 @@ tags:
|
|||||||
|
|
||||||
Cross-topic of [[statistical-modeling]] and [[construction-estimating]].
|
Cross-topic of [[statistical-modeling]] and [[construction-estimating]].
|
||||||
|
|
||||||
|
%%
|
||||||
|
## TALK
|
||||||
|
|
||||||
|
This note should discuss the application of modeling in estimating,
|
||||||
|
including what is already common practice (e.g. average run lengths),
|
||||||
|
as well as the potential for more robust models.
|
||||||
|
|
||||||
|
Models are useful where information is limited,
|
||||||
|
and where more precise methods would be suboptimal[^1].
|
||||||
|
|
||||||
|
[^1]: see [[risk-management-for-construction-estimating]].
|
||||||
|
|
||||||
|
Specific examples should generally be relegated to linked notes.
|
||||||
|
|
||||||
|
%%
|
||||||
|
|
||||||
## Bayesian Takeoff
|
## Bayesian Takeoff
|
||||||
|
|
||||||
#### User Story
|
#### User Story
|
||||||
|
|||||||
+1
-1
@@ -3,7 +3,7 @@ id:
|
|||||||
aliases: []
|
aliases: []
|
||||||
tags:
|
tags:
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/subfeeds
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
- authorship/original
|
- authorship/original
|
||||||
|
|||||||
@@ -4,7 +4,7 @@ aliases: []
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/switchgear
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Switchgear
|
title: Switchgear
|
||||||
|
|||||||
+1
-1
@@ -4,7 +4,7 @@ aliases: []
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/telecom
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Telecom
|
title: Telecom
|
||||||
|
|||||||
@@ -1,16 +1,23 @@
|
|||||||
---
|
---
|
||||||
id:
|
id:
|
||||||
aliases: []
|
aliases: []
|
||||||
|
title: Transparency in Construction Estimating
|
||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- status/incomplete
|
- status/not-started
|
||||||
- topic/construction
|
- topic/construction
|
||||||
- topic/estimating
|
- topic/estimating
|
||||||
- type/philosophy
|
- topic/transparency
|
||||||
title: Estimating Ethics
|
- type/cross-topic
|
||||||
---
|
---
|
||||||
# Estimating Ethics
|
# Transparency in Construction Estimating
|
||||||
|
|
||||||
|
Cross-topic of [[transparency]] and [[construction-estimating]].
|
||||||
|
|
||||||
|
## Estimating Ethics
|
||||||
|
|
||||||
|
### Ethics for the Solicitor
|
||||||
|
|
||||||
Contractors engaging in unethical bidding practices
|
Contractors engaging in unethical bidding practices
|
||||||
can quickly gain a reputation for doing so,
|
can quickly gain a reputation for doing so,
|
||||||
@@ -24,15 +31,7 @@ To ensure a transparent bidding process, one must
|
|||||||
* maintain confidentiality of bid submissions, and
|
* maintain confidentiality of bid submissions, and
|
||||||
* provide equal access to bidding information.
|
* provide equal access to bidding information.
|
||||||
|
|
||||||
### Terms
|
### Ethics for the Bidder
|
||||||
|
|
||||||
> [!info] Bid Shopping
|
|
||||||
> the practice of sharing a bidder's quote with other prospective vendors
|
|
||||||
> in order to solicit lower bids.
|
|
||||||
> The competing quote may be legitimate, fabricated,
|
|
||||||
> or a non-serious proposal from a colluding vendor.
|
|
||||||
|
|
||||||
## Bad Bid Practice
|
|
||||||
|
|
||||||
Deceptive proposal language is a quick way to get blacklisted.
|
Deceptive proposal language is a quick way to get blacklisted.
|
||||||
|
|
||||||
@@ -43,3 +42,11 @@ is particularly reprehensible.
|
|||||||
> * Not including consideration for voltage drop
|
> * Not including consideration for voltage drop
|
||||||
> * Including standard, line-voltage switching as "lighting control"
|
> * Including standard, line-voltage switching as "lighting control"
|
||||||
> * Excluding all mechanical disconnects
|
> * Excluding all mechanical disconnects
|
||||||
|
|
||||||
|
### Terms
|
||||||
|
|
||||||
|
> [!info] Bid Shopping
|
||||||
|
> the practice of sharing a bidder's quote with other prospective vendors
|
||||||
|
> in order to solicit lower bids.
|
||||||
|
> The competing quote may be legitimate, fabricated,
|
||||||
|
> or a non-serious proposal from a colluding vendor.
|
||||||
+3
-5
@@ -7,7 +7,7 @@ aliases:
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/standalone-systems
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Two-Way Takeoff
|
title: Two-Way Takeoff
|
||||||
@@ -33,9 +33,7 @@ title: Two-Way Takeoff
|
|||||||
* FCR to elevator lobbies
|
* FCR to elevator lobbies
|
||||||
* FCR to stairwells
|
* FCR to stairwells
|
||||||
|
|
||||||
**Count** = Number of boxes run to. Per drawings if shown, otherwise use the greater of:
|
**Count** = Count of elevator lobbies or stairwells (match length)
|
||||||
* Count of elevators
|
|
||||||
* Count of stairwells
|
|
||||||
|
|
||||||
## Vertical
|
## Vertical
|
||||||
|
|
||||||
@@ -44,7 +42,7 @@ title: Two-Way Takeoff
|
|||||||
`FIRE ALARM & DAS SYSTEMS`/`TWO WAY COMMUNICATION ASSEMBLIES`/`2-WAY COMMUNICATION = 1" CONDUIT ...`
|
`FIRE ALARM & DAS SYSTEMS`/`TWO WAY COMMUNICATION ASSEMBLIES`/`2-WAY COMMUNICATION = 1" CONDUIT ...`
|
||||||
|
|
||||||
* **Length** = 15ft * Count
|
* **Length** = 15ft * Count
|
||||||
* **Count** = _match Horizontal_
|
* **Count** = match Horizontal
|
||||||
|
|
||||||
## Firefighter Phone System
|
## Firefighter Phone System
|
||||||
|
|
||||||
|
|||||||
@@ -0,0 +1,62 @@
|
|||||||
|
---
|
||||||
|
id:
|
||||||
|
aliases: []
|
||||||
|
title: Uncertainty in Construction Estimating
|
||||||
|
tags: []
|
||||||
|
---
|
||||||
|
# Uncertainty in Construction Estimating
|
||||||
|
|
||||||
|
Cross-topic of [[uncertainty]] and [[construction-estimating]].
|
||||||
|
|
||||||
|
This note is intended to be purely descriptive.
|
||||||
|
See [[actuarial-science-for-construction-estimating]]
|
||||||
|
and [[risk-management-for-construction-estimating]]
|
||||||
|
for strategy based on such uncertainty.
|
||||||
|
|
||||||
|
%%
|
||||||
|
## TALK
|
||||||
|
|
||||||
|
What do I mean that project cost is uncertain until the last invoice?
|
||||||
|
|
||||||
|
What distributions exist
|
||||||
|
which are known,
|
||||||
|
which can never be known and must be estimated?
|
||||||
|
|
||||||
|
[[bid-price-modeling]]
|
||||||
|
|
||||||
|
***
|
||||||
|
|
||||||
|
With perfect information all outcomes are certain.
|
||||||
|
|
||||||
|
There exists some distribution representing the range of possible costs for a project.
|
||||||
|
The remaining uncertainty represents ignorance of information an estimator can not feasibly obtain.
|
||||||
|
|
||||||
|
***
|
||||||
|
|
||||||
|
Suppose the estimator has spent years on the bid,
|
||||||
|
running simulations, consulting experts, etc.
|
||||||
|
|
||||||
|
Suppose the estimator has received a message from a time traveler
|
||||||
|
which details significant news events and commodity markets
|
||||||
|
for the duration of the project.
|
||||||
|
|
||||||
|
Suppose the estimator is prescient and has observed the final cost of the project
|
||||||
|
as reported in the winning contractor's historicals.
|
||||||
|
|
||||||
|
%%
|
||||||
|
|
||||||
|
## Expected Value of Perfect Information
|
||||||
|
|
||||||
|
[[uncertainty#Expected Value of Perfect Information]]
|
||||||
|
|
||||||
|
%%
|
||||||
|
|
||||||
|
an organization pays in estimator hours.
|
||||||
|
These hours have a direct cost in salary and benefits,
|
||||||
|
however the greater cost is the opportunity cost
|
||||||
|
of tying up an estimator who could otherwise be starting a new project.
|
||||||
|
|
||||||
|
In many cases, the utility of doubled throughput
|
||||||
|
far outweighs the increased risk of individual bids.
|
||||||
|
|
||||||
|
%%
|
||||||
@@ -75,19 +75,6 @@ in order to gain access to perfect information.
|
|||||||
The perceived _value_ of decreased uncertainty
|
The perceived _value_ of decreased uncertainty
|
||||||
must be weighed against its _cost_.
|
must be weighed against its _cost_.
|
||||||
|
|
||||||
#### In Construction Estimating
|
|
||||||
|
|
||||||
This concept provides the basis for the solution
|
|
||||||
of one or more [[open-problems-in-estimating]].
|
|
||||||
To reduce [[risk]] in [[construction-estimating]],
|
|
||||||
an organization pays in estimator hours.
|
|
||||||
These hours have a direct cost in salary and benefits,
|
|
||||||
however the greater cost is the opportunity cost
|
|
||||||
of tying up an estimator who could otherwise be starting a new project.
|
|
||||||
|
|
||||||
In many cases, the utility of doubled throughput
|
|
||||||
far outweighs the increased risk of individual bids.
|
|
||||||
|
|
||||||
## Types of Uncertainty
|
## Types of Uncertainty
|
||||||
|
|
||||||
### Aleatory Uncertainty
|
### Aleatory Uncertainty
|
||||||
|
|||||||
+1
-1
@@ -4,7 +4,7 @@ aliases: []
|
|||||||
tags:
|
tags:
|
||||||
- authorship/original
|
- authorship/original
|
||||||
- destiny/permanent
|
- destiny/permanent
|
||||||
- occupational/takeoff/units
|
- occupational/takeoff
|
||||||
- status/draft
|
- status/draft
|
||||||
- type/guide
|
- type/guide
|
||||||
title: Unit Takeoff
|
title: Unit Takeoff
|
||||||
|
|||||||
Reference in New Issue
Block a user