%&tex
    \subsection{Requirements}
    \label{sec:specifications}
        The next step is to create requirements based on the problem description.
        The goal is to write and erase a tweet on the whiteboard.
        Originally a tweet had a character limit of 140, but this was doubled to 280\autocite{rosen_tweeting_2017}.
        However, the decision is made to keep the limit at 140, as it does not improve the case study but can increase the construction cost.
        The text is limited to fifty characters per line, with a total of three lines.
        For the readability, the distance to a whiteboard in a meeting room is taken as four meters.
        The operating speed must allow the tweet to be written within three minutes. 
        Therefore, the goal is to write one character per second.
        The last requirement is that the dynamics of the system must be sophisticated.
        Meaning that a solution with complex or non-trivial behavior is preferred.
        Using \ac{ears} to define these requirements gives:
        \begin{specification}
            \begin{enumerate}
                \setlength{\itemsep}{10pt}
                    \input{content/input/speclista.tex}
        \end{enumerate}
        \end{specification}
        Some other requirements that are related to the operation of the system are:
        \begin{specification}
            \begin{enumerate}
                \setcounter{enumi}{8}
                \setlength{\itemsep}{10pt}
                    \input{content/input/speclistb.tex}
            \end{enumerate}
        \end{specification}

        Additionally there are some restrictions on construction.
        As the rapid prototyping facilities at the university are closed due to the Covid-19 pandemic, the available tooling in reduced to my personal tools:
        \begin{specification}
            \begin{itemize}
                \setlength{\itemsep}{10pt}
                \item The Writer shall not exceed a total cost in materials and/or tools of €200.
                \item The Writer shall be constructed with simple tools in the following list:
                    \begin{itemize}
                        \item Screwdrivers (Hex/Inbus, Torx, Philips, etc)
                        \item Drill
                        \item Screwtaps
                        \item Jigsaw
                        \item Wrenches
                        \item Soldering iron
                        \item Various Pliers 
                        \item PLA 3D printer
                    \end{itemize}
            \end{itemize}
        \end{specification}
        \subsubsection{Evaluation}
            The requirements step was performed without problems.
            Defining the requirements for the problem description did not present any difficulty.
            Due to the simplicity of the problem description, there were no contradictory requirements, which would complicate the requirements step.
            Furthermore, a single stakeholder takes away any negotiation between stakeholders.
            Where the stakeholders are a combination of engineers on the design team and/or the project client.

            Although the requirements itself are not difficult to define, ensuring that they are complete is difficult.
            Discussion between team members and stakeholders helps to spot any ambiguity or problems with the validity.
            \ac{ears} was very useful in this case as it gives a strong template to help avoid ambiguity.
