Rephrased longetivity definition

Before this commit, Longetivity was defined on the basis of the term
usability. Although the scope and context of the term has been mentioned
right after its use, this could have caused confusion with the keyword
"usability" in the field of software engineering.

With this commit, Longetivity definition has been rephrased in a way that
it would not require "usability". Furthermore, since longetivity would
logically require the availability of the machines and platforms during the
time of re-use, this has been explicitly mentioned in the definition.

1 files changed, 4 insertions, 3 deletions

diff --git a/paper.tex b/paper.tex
index 9e233de..08dab9f 100644
--- a/paper.tex
+++ b/paper.tex
@@ -126,8 +126,9 @@ Decades later, scientists are still held accountable for their results and there
 \section{Longevity of existing tools}
 \label{sec:longevityofexisting}
 \new{Reproducibility is defined as ``obtaining consistent results using the same input data; computational steps, methods, and code; and conditions of analysis'' \cite{fineberg19}.
-Longevity is defined as the length of time that a project remains \emph{usable}.
-Usability is defined by context: for machines (machine-actionable, or executable files) \emph{and/or} humans (readability of the source).
+We define \emph{longevity} as the length of time that the source of a project remains:
+(1) readable for humans, \emph{and}
+(2) \emph{machine-actionable} \emph{and/or} executable for the available machines and platforms during the very time span.
 Many usage contexts do not involve execution: for example, checking the configuration parameter of a single step of the analysis to re-\emph{use} in another project, or checking the version of used software, or the source of the input data.
 Extracting these from the outputs of execution is not always possible.}
 
@@ -162,7 +163,7 @@ Hence, if the image is built in different months, its output image will contain
 In the year 2024, when long-term support for this version of Ubuntu expires, the image will be unavailable at the expected URL.
 Generally, Pre-built binary files (like Docker images) are large and expensive to maintain and archive.
 %% This URL: https://www.docker.com/blog/docker-hub-image-retention-policy-delayed-and-subscription-updates}
-\new{Because of this DockerHub (where many reproducible workflows are archived) announced that inactive images (older than 6 months) will be deleted in free accounts from mid 2021.}
+\new{Because of this, DockerHub (where many reproducible workflows are archived) announced that inactive images (older than 6 months) will be deleted in free accounts from mid 2021.}
 Furthermore, Docker requires root permissions, and only supports recent (``long-term-support'') versions of the host kernel, so older Docker images may not be executable \new{(their longevity is determined by the host kernel, typically a decade)}.
 
 Once the host OS is ready, PMs are used to install the software or environment.