vault backup: 2026-01-11 12:50:45

2026-01-11 12:50:45 -05:00
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@@ -0,0 +1,67 @@
+---
+id:
+aliases: []
+title: 2026-01-11
+tags:
+  - authorship/original
+  - destiny/permanent
+  - status/draft
+  - type/daily
+---
+# 2026-01-11
+
+## 2026-01-11 09:00
+
+[[2026-01-09#2026-01-09 14:45]]
+
+[[bid-price-modeling]]
+
+[[decrease-in-sigma]]
+
+## 2026-01-11 11:00
+
+![[favorite-quotes#"It Takes an Engineer to Build a Bridge that Barely Stands"]]
+
+The value that estimators provide for a contractor
+is in modeling project cost.
+If the goal were simply to present a number the cost will not exceed,
+than anyone could be an estimator.
+If the goal were only to present a reasonably accurate figure,
+with no other constraints,
+then there are few who in the world who couldn't,
+given infinite time for a single bid.
+The _true_ value of an estimator, then,
+is in their ability to model project cost _efficiently_, that is,
+to achieve acceptable accuracy and precision as quickly as possible,---
+much as the engineer's is in building a bridge that _meets_ the requirements
+as cheaply as possible.
+
+Estimating "as accurately as possible"
+is akin to building a bridge "as strong as possible";
+it sounds nice, but ignores the actual objective of _optimal cost-efficiency_.
+
+I think that most estimators believe this to be the case,
+but, whatever they believe in mind, they believe in practice
+that the goal is to model cost as accurately and precisely as possible,
+_given the time allowed for bid_.
+Estimates tend always to take exactly as many weeks as until the bid due date,
+even those of significantly different turnaround but equal scope and complexity.
+This behavior is objectionable,
+since if an acceptable estimate _could_ be provided in two weeks,
+it is not cost-effective[^1] to allow it to take four.[^2]
+
+[^1]: "Cost" referring both to estimator salaries and the opportunity cost of declined bids.
+
+[^2]: Supposing a contractor maintained a modern portfolio theory styled record
+    of estimates including pending bids, and projects ongoing and completed,
+    with confidence estimates uncorrupted by [[estimating-culture#Incentives|perverse incentives]],
+    they may have reasonable basis to set sliding standards for estimate precision
+    to be specifically determined at consideration of the opportunity for bid
+    according to current climate (i.e. their risk appetite).
+    I believe my use of the absolute is still fair.
+    No contractor is doing that, so they lack a competent measure of risk tolerance
+    besides continuing to tolerate what they have historically.
+
+Objectionable as it is,
+it is to be expected that estimators will use all time allowed them
+when the standards for _acceptability_ are inadequately defined.
@@ -23,4 +23,4 @@ In this way, projects are better compared to _insurance accounts_.
 * cost of individual service is uncertain
 * cost to customer must be minimized

-![[decrease-in-sigma#^pdf]]
+![[decrease-in-sigma#Normal PDF]]
@@ -1,5 +1,5 @@
 ---
-id: risk-oriented-estimating
+id:
 aliases: []
 title: Bid Process Strategy
 tags:
@@ -17,6 +17,10 @@ are currently disparate, disjointed, and redundant.

 ## TODO

+### Supertopic: Risk-Oriented Estimating
+
+Still deciding if I'm capable of being opinionated without rambling.
+
 ### Legitimate Subtopics

 * [[estimating-methodologies]]
@@ -40,7 +44,7 @@ Create and use cross-topic notes for complex thoughts:
    * [[bid-process-strategy]]

 * [[game-theory-for-construction-estimating]]
-    * [[estimating-culture]]: estimator incentives
+    * [[estimating-culture#Incentives]]

 * [[project-management-for-construction-estimating]]
    * [[separating-estimating-concerns]]
@@ -40,6 +40,7 @@ For philosophy see [[bid-process-strategy]]
 * [[auction-theory-for-construction-estimating]]
 * [[game-theory-for-construction-estimating]]
 * [[project-management-for-construction-estimating]]
+* [[utility-in-construction-estimating]]
 * [[ambiguity-in-construction-estimating]]
 * [[nontraditional-computing-for-construction-estimating]]
 * [[object-oriented-programing-for-construction-estimating]]
@@ -11,6 +11,8 @@ tags:
 ---
 # Decrease in Sigma

+## Normal PDF
+
 ```tikz
 \usepackage{pgfplots}
 \pgfplotsset{compat=1.16}
@@ -47,53 +49,62 @@ tags:
 \end{document}
 ```

-^pdf
+## Lognormal PDF

-```tikz
-\usepackage{pgfplots}
-\pgfplotsset{compat=1.16}
+![[lognormal-pdf.gif]]

-\pgfmathdeclarefunction{erfapprox}{1}{%
-  \pgfmathparse{%
-    % save sign and work with |x|
-    ( (#1<0) ? -1 : 1 )
-    * ( 1 - (1 + 0.278393*abs(#1) + 0.230389*abs(#1)^2 + 0.000972*abs(#1)^3 + 0.078108*abs(#1)^4)^(-4) )
-  }%
-}
+%%
+```python
+import numpy as np
+import matplotlib.pyplot as plt
+from scipy.stats import lognorm
+import imageio.v2 as imageio
+import os

-% Normal CDF using erf approximation:
-% F(x;mu,sigma) = 0.5*(1 + erf((x-mu)/(sigma*sqrt(2))))
-\pgfmathdeclarefunction{normcdf}{3}{%
-  \pgfmathparse{ 0.5*(1 + erfapprox((#1-#2)/(#3*sqrt(2)))) }%
-}
+mean_target = 10.0
+sigmas = np.linspace(1.0, 0.1, 25)
+x = np.linspace(0.001, 40, 2000)

-\begin{document}
-\begin{tikzpicture}
-    \begin{axis}[
-      width=13cm,
-      height=7cm,
-      axis lines=middle,
-      xlabel={$x$},
-      ylabel={$F(x;\mu,\sigma)$},
-      xmin=-6, xmax=6,
-      ymin=0, ymax=1.05,
-      samples=400,
-      domain=-6:6,
-      legend style={draw=none, fill=none, at={(0.02,0.98)}, anchor=north west},
-      legend cell align=left,
-      ytick={0,0.5,1},
-    ]
+# Precompute global y-limit
+pdf_max = 0.0
+for sigma in sigmas:
+    mu = np.log(mean_target) - 0.5 * sigma**2
+    pdf = lognorm.pdf(x, s=sigma, scale=np.exp(mu))
+    pdf_max = max(pdf_max, pdf.max())

-    % Normal CDF: 0.5*(1 + erf((x-mu)/(sigma*sqrt(2))))
-    \addplot[thick]
-      { normcdf(x,0,1.8) };
-    \addlegendentry{$\mu=0,\ \sigma=1.8$}
+frames = []
+tmp_dir = "frames"
+os.makedirs(tmp_dir, exist_ok=True)

-    \addplot[thick, dashed]
-      { normcdf(x,0.8) };
-    \addlegendentry{$\mu=0,\ \sigma=0.8$}
+for i, sigma in enumerate(sigmas):
+    mu = np.log(mean_target) - 0.5 * sigma**2
+    pdf = lognorm.pdf(x, s=sigma, scale=np.exp(mu))

-    \end{axis}
-\end{tikzpicture}
-\end{document}
+    plt.figure(figsize=(6, 4))
+    plt.plot(x, pdf)
+    plt.axvline(mean_target, linestyle="--", linewidth=1)
+    plt.text(
+        mean_target, pdf_max * 0.95,
+        "mean",
+        rotation=90,
+        verticalalignment="top",
+        horizontalalignment="right"
+    )
+
+    plt.title(f"Lognormal PDF\nmean = {mean_target}, sigma = {sigma:f}")
+    plt.xlabel("x")
+    plt.ylabel("density")
+    plt.ylim(0, pdf_max * 1.05)
+    plt.tight_layout()
+
+    frame_path = f"{tmp_dir}/frame_{i:02d}.png"
+    plt.savefig(frame_path, dpi=120)
+    plt.close()
+
+    frames.append(imageio.imread(frame_path))
+
+os.makedirs("out", exist_ok=True)
+gif_path = "out/lognormal-pdf.gif"
+imageio.mimsave(gif_path, frames, duration=0.15)
 ```
+%%
@@ -34,6 +34,29 @@ tags:

 ## About Process Optimization

+### "It Takes an Engineer to Build a Bridge that Barely Stands"
+
+> [!quote] Unknown
+> Any idiot can build a bridge that stands.
+> It takes an engineer to build a bridge that barely stands.
+
+The phrase "exceeds specifications"
+ought not be universally perceived as positive when divorced from context like it is.
+
+It is often the case that exceeding minimum requirements is easy,
+and that the difficulty (the kind that you pay people to handle)
+is in meeting them precisely.
+
+In the case of civil infrastructure,
+it is intuitive that even though a 10% safety factor is _good_,
+a 100% safety factor is not _better_.
+It is _so_ intuitive that the choice of "_barely_ stands",
+I don't think would give many pause or reservation.
+
+However, divorced from context,
+people are biased to believe that more of a good thing must be better,
+especially when what's compromised isn't as tangible as dollars on an invoice.
+
 ### "Sharpen the Axe"

 Frequently misattributed to Abraham Lincoln is some variation of:
@@ -9,6 +9,15 @@ tags:
 ---
 # Music Theory as Code

+%%
+## TALK
+
+For now a scratchpad for implementation,
+ultimately to discuss the difficulty
+and why every extant library
+seems to have wildly different ergonomics and terminology
+%%
+
 PowerShell module to assist in translating between banjo fingerings and concert notes,
 as well as between [[lilypond]] and conventional notation.

@@ -12,3 +12,10 @@ tags:
 # Music Theory for Banjo

 Cross-topic of [[music-theory]] and [[banjo]].
+
+%%
+## TALK
+
+practical application of music theory concepts for playing banjo
+including vocal accompaniment.
+%%
@@ -11,3 +11,24 @@ tags:
 # Nontraditional Computing

 **Nontraditional computing** refers to UX patterns
+unlike those originally pioneered by Xerox and IBM,
+and cemented by Apple and Microsoft.
+
+Desktops, hierarchical filesystems,
+obligatory mouse and keyboard
+
+Perhaps more accurate is **nontraditional _business_ computing**,
+since the real innovation is making mobile device patterns practical.
+
+Designers frequently malign traditional computing,
+stating accurately that it was a compromise
+for restrictions that we no longer face,
+but there is very little movement
+on practical implementation of nontraditional patterns.
+[Ink & Switch](https://www.inkandswitch.com/)
+is at the forefront as I understand it,
+however they have as much effort or more
+invested in traditional systems.
+
+[Liber Indigo](https://www.justinckirkwood.net/liber-indigo)
+is mostly woo-woo, but has some fun things to say about NTC.
@@ -1,37 +0,0 @@
---
-id:
-aliases: []
-tags:
-  - authorship/original
-  - destiny/fleeting
-  - status/incomplete
-  - topic/estimating
-  - topic/software
-  - type/idea
-title: Optimal Estimating Patterns
---
-# Optimal Estimating Patterns
-
-[[construction-estimating-software]] consistently fails to innovate
-on the stale patterns developed for marginally similar applications decades ago.
-
-## More Optimal Patterns
-
-> [!note]
-> Note that while the patterns described below
-> _are_ more optimal than those of traditional applications,
-> the bigger problem with such applications
-> is their suboptimal implementation of their patterns.
-> If you could just do what they're trying to do correctly,
-> you probably wouldn't need all these optimizations anyway.
-
-%% TODO:
-
-Count-based takeoff speed increases with count.
-
-Optimizing the takeoff process means:
-
-* _Minimizing_ the need for information outside of drawings
-* _Maximizing_ organizational consistency
-
-%%
@@ -15,15 +15,31 @@ tags:

 Cross-topic of [[risk-management]] and [[construction-estimating]].

-## Estimating as Risk Mitigation
+%%
+## TALK

-* reduce risk of wasted estimation effort due to bid loss
-  (prefer lower bid)
-* reduce risk of project overrun
-  (prefer higher bid)
+
+%%
+
+## Bid Risk
+
+**Bid risk** is not only risk of project overrun given award,
+but also includes the risk of wasted estimation effort due to bid loss,
+and the opportunity cost of excluding other opportunities.
+
+## Estimating as Risk Mitigation

 Estimating resources should be allocated
 according to Return on Mitigation (RoM),
 that is, their contribution to _cost certainty_.

 $\text{Efficiency} = -1 \times \frac{d\sigma}{dt}$
+
+But the RoM of estimating effort has a steep drop off,
+and cost will obviously never be entirely certain.
+
+It is not foolhardy to tolerate imprecision in an estimate
+when the effort to increase precision
+will not decrease bid risk at least equivalently
+
+(stigmatizing "assumptions")
@@ -18,6 +18,8 @@ They are a group of topics that,
 while they may seem disparate in a vacuum,
 are all fundamental to a greater understanding of the whole.

+
+
 %%

 ## TALK
@@ -51,19 +51,3 @@ Suppose the estimator is prescient and has observed the final cost of the projec
 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.
-
-%%
@@ -0,0 +1,31 @@
+---
+id:
+aliases: []
+title:
+tags:
+  - authorship/original
+  - destiny/permanent
+  - status/incomplete
+  - topic/estimating
+  - topic/risk
+  - type/cross-topic
+---
+# Utility in Construction Estimating
+
+Cross-topic of [[utility]] and [[construction-estimating]].
+
+## 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.
+
+%%
@@ -14,3 +14,7 @@ tags:
 [Utility](https://en.wikipedia.org/wiki/Utility)
 is a measure of a party's satisfaction
 with a certain state of the world.
+
+The measure is intended to account for unintuitive quirks of human perception of value.
+A rich man is not as satisfied with receiving one dollar as a poor man,
+therefore the utility of the dollar is contextual, not objective.