diff --git a/.gitmodules b/.gitmodules
index 68d937b..0ded18e 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,3 @@
 [submodule "common"]
 	path = include
-	url = ssh://git@git.ram.eemcs.utwente.nl:20022/horlingsw/mac.git
+	url = https://git.ram.eemcs.utwente.nl/horlingsw/mac.git
diff --git a/content/introduction.tex b/content/introduction.tex
index 3b331fb..7417002 100644
--- a/content/introduction.tex
+++ b/content/introduction.tex
@@ -1,3 +1,82 @@
 %&tex
-\chapter{introduction}
+\chapter{Introduction}
 \label{introduction}
+\section{Context of this Thesis}
+    \ac{cps} integrate computation and physical components as an engineered system.
+    Automobiles, robots, medical devices and even the smart grid are examples of \ac{cps}.
+    The complexity of \ac{cps} has gone from an embedded system that improved the fuel consumption of a car engine to a fully self-driving vehicle.
+    Although the complexity opens up more design possibilities, improved efficiency and safety, it has downsides.
+    The problem with the increasing complexity is the resulting increased developing cost and the decreasing reliability.
+    Within the research topics that focus on \ac{cps}, lies the development of new design methods that deal with this complexity problem.
+    The \emph{design method} by \textcite{broenink_rapid_2019} is one of these new design methods and focusses on the rapid development of embedded control software.
+    The rapid development is a design technique that splits the development into small individual steps, which can be implemented and tested separately.
+    Testing each individual step creates feedback on a short interval, with the goal to detect errors made during the development as early as possible.
+    As part of the research, Broenink and Broenink performed a small case study.
+    In this case study, they have designed a controller, and implemented the controller in software for a physical off-the-shelf system.
+    However, developing \ac{cps} incorporates both the computational software side, as well as the development of the physical dynamic side, although the latter is not covered by Broenink and Broenink.
+    For this design method to be suitable for a complete design of \ac{cps} it has to be applicable to the physical part as well.
+    
+    %%In this thesis, the proposed design method is applied and evaluated in the context of the physical part of a \ac{cps}.
+    %%This is done in a case study, where a \ac{cps} is designed from scratch.
+\section{Research Objective}
+    \textcite{broenink_rapid_2019} present a case study for software in their paper and state that "this [case study] does not mean that the same techniques cannot be applied to the physical part of the system."
+    In this thesis, I will research whether this design method applies to the physical part of a \ac{cps}, to come to a design method that can be applied on both the physical and cyber (software) part of a \ac{cps}.
+    From the start of this research, it was clear that a direct copy of the design method is not possible.
+    It is therefore necessary to analyse which design techniques cannot be used and thus how to replace or improve them.
+    The research is summarized in the following two research questions:
+    \begin{itemize}
+        \item Which design techniques of the design method by \textcite{broenink_rapid_2019} can be applied developing the physical part of \ac{cps}?
+        \item Which adaptations are required to make the design method by \textcite{broenink_rapid_2019} suitable for developing the computation and physical part of \ac{cps}?
+    \end{itemize}
+
+\section{Approach}
+    Within this thesis, the design method by \textcite{broenink_rapid_2019} is evaluated in a case study.
+    The case study performs a development process according to the design method and will evaluate the result.
+    However, there are a couple of steps required prior to the start of the case study (see \autoref{fig:approach}).
+    The first step is to produce a concrete \emph{design plan} based on the design method.
+    The concrete design plan improves the evaluation of the design techniques.
+    The design method is presented in an abstract form which leaves room for interpretation.
+    This hampers the evaluation process, because it is impossible to point out flaws in something that was not specific in the first place.
+    Therefore, I will assess the design method and add detail to get a concrete design plan.
+    Because the design method focusses on the rapid development principles and modelling techniques, it does not cover the design steps outside of that focus.
+    These steps, like problem definition and system specifications, are a crucial part of the design process and are added to create the concrete design plan.
+    The added steps are based on the steps in a \ac{se} approach.
+    \begin{figure}
+        \centering
+        \includegraphics[width=9cm]{graphics/approach.pdf}
+        \caption{A graph that shows the interconnection of the different steps that are required to prior to the start of the case study.}
+        \label{fig:approach}
+    \end{figure}
+
+    With a design plan to use in the case study there are two steps of preparation left.
+    The first step is to develop an evaluation plan to ensure complete and consistent feedback during the case study.
+    The evaluation plan consists of a list of questions that have to be evaluated for each design step.
+    There are specific questions that evaluate the definition, or the execution of the design step.
+    The other step is to provide the \emph{subject of design} to develop in the case study.
+    Normally, the design process focusses on delivering the end product in the most effective manner.
+    However, the goal of this research is to use the design process to evaluate the design method, not to develop a product.
+    A possible pitfall is that during the design process a simple solution is found, such that the design techniques to deal with the increased complexity are left untouched.
+    Choosing to develop a very complex subject would ensure that all the design techniques are used, except that the limited time budget of a master's thesis does not allow that.
+    One of the requirements for the possible subjects is therefore a minimum level of complexity, forcing the developer to not go with the simplest solution.
+    Some other requirements, based on practical decisions like budget, tools, and time were defined as well.
+    Based on these requirements, the subject of choice is "Writing a tweet on a whiteboard".
+    
+    With something to develop, a method to develop, and a method to evaluate, the case study is executed.
+    Even though the case study was terminated due to the limited amount of time available, it resulted in a partial prototype of a whiteboard writer and a significant amount of evaluation.
+    The results made it possible to propose improvements to the design method, not only for the physical part of \ac{cps} but also the cyber part.
+
+\section{Notes on Terminology}
+    Design method is a commonly-used notion throughout the different papers and research used in this thesis.
+    \textcite{broenink_rapid_2019} refer to their design method as 'the methodology', which is to generic for this thesis.
+    To ensure distinct terminology throughout this thesis, their methodology is named \acl{ridm} and is abbreviated as \acs{ridm}.
+    The more concrete version of the design method that is tested in the case study, will be referred to as the 'design plan'.
+    The object or system that is going to be designed during the case study is referred as 'subject of design'.
+
+\section{Structure}
+    The refinement of the design method and adding design steps is done in \autoref{analysis} to define a concrete design plan.
+    The evaluation plan and subject of design is defined in \autoref{case_method}.
+    The case study is executed in \autoref{case_experiment}, based on the design plan, evaluation plan and subject of design.
+    The execution of the case study is evaluated in \autoref{case_evaluation}.
+    In \autoref{reflection} the evaluation of the case study and the results are reflected back on the design plan.
+    Based on the reflection and the evaluation, an improved design method is proposed in \autoref{improved_design}.
+    And finally, the research is concluded in \autoref{conclusion}.
diff --git a/graphics/approach.tex b/graphics/approach.tex
new file mode 100644
index 0000000..c8add0f
--- /dev/null
+++ b/graphics/approach.tex
@@ -0,0 +1,19 @@
+%&tex
+\documentclass{standalone}
+\usepackage{tikz}
+\usetikzlibrary {quotes,arrows.meta,graphs,graphdrawing} \usegdlibrary {layered}
+\tikzset{nodes={text height=.7em, text width=2.7cm, align=center,
+draw=black!20, thick, fill=white, font=\footnotesize},
+>={Stealth[round,sep]}, rounded corners, semithick}
+
+\begin{document}
+
+\begin{tikzpicture}
+
+\graph [layered layout, level distance=1.2cm, sibling sep=.5em, sibling distance=1.5cm, sweep crossing minimization] {
+{"Design Method", "System Engineering"} -> "Design Plan";
+{"Evaluation Plan", "Design Plan", "Subject of design"} -> "Case Study";
+};
+\end{tikzpicture}
+\end{document}
+
diff --git a/include b/include
index 696eebe..53a54d3 160000
--- a/include
+++ b/include
@@ -1 +1 @@
-Subproject commit 696eebe3534f7e5133f8c2c4fa1f9c84e0910997
+Subproject commit 53a54d3e4842e0ad2991fe196a02c8e35cbc2600