|
|
@@ -1,3 +1,42 @@ |
|
|
%&tex |
|
|
%&tex |
|
|
\chapter{case evaluation} |
|
|
|
|
|
\label{case_evaluation} |
|
|
|
|
|
|
|
|
\chapter{Case Evaluation} |
|
|
|
|
|
\label{chap:case_evaluation} |
|
|
|
|
|
|
|
|
|
|
|
\section{Preparation Phase} |
|
|
|
|
|
\subsection{One-man development team} |
|
|
|
|
|
The case study was performed by me, as a single developer. |
|
|
|
|
|
Against all expectations, this one-man development team made the preparation phase more difficult instead of easier. |
|
|
|
|
|
The goal of the problem description and the specifications step is to get the stakeholders on the same line \autocite{shafaat_exploring_2015}. |
|
|
|
|
|
This involves creating agreed-upon requirements for the system, but with only one stakeholder, this agreement is implicit. |
|
|
|
|
|
Moreover, it undermines the incentive of the problem description and specifications step. |
|
|
|
|
|
Part of this is that there is no penalty for future reviews of the specifications, as I already agreed. |
|
|
|
|
|
|
|
|
|
|
|
Furthermore, specific details and decisions were often made subconsciously, while I was commuting, waiting in line, or even showering. |
|
|
|
|
|
Making structured documentation of these decisions at a later point in time without missing any of them was impossible. |
|
|
|
|
|
The social interaction within a design team stimulates this documenting process as it improves the recall and interpretation of information. |
|
|
|
|
|
It also improves the judgement and selection between design alternatives \autocite{lamb_221_2008}. |
|
|
|
|
|
|
|
|
|
|
|
\subsection{Information Flow} |
|
|
|
|
|
%% Aanknopen op het vorige verhaal? |
|
|
|
|
|
Although team members improve the information flow within a design team, it does not guarantee that all information is available. |
|
|
|
|
|
Throughout the case study, more and more information becomes available. |
|
|
|
|
|
During the initial design, new insight was gained that would have been useful during the problem description and the specifications step. |
|
|
|
|
|
And while making the tests, it became clear that the specifications were incomplete. |
|
|
|
|
|
It is possible to review the specifications step, but the succeeding steps have to be redone as well. |
|
|
|
|
|
During the case study, I decided to continue with the design due to the scope of the research, namely the development design cycle was. |
|
|
|
|
|
|
|
|
|
|
|
Dealing with these design changes is a known weakness of the waterfall model. |
|
|
|
|
|
Many publications give credit to \textcite{royce_managing_1970}, for the concept of the waterfall model. |
|
|
|
|
|
Where they refer to the simple 5 to 8 step design concept, similar to the one in \autoref{sec:SE}. |
|
|
|
|
|
What these publications fail to address is that \textcite{royce_managing_1970} says: "I believe in this concept, but the implementation described above is risky and invites failure." |
|
|
|
|
|
Followed by multiple steps of improving the waterfall model. |
|
|
|
|
|
Royce adds a complete design step, loads of intermittent testing and documentation, and a literal instruction "Do it twice". |
|
|
|
|
|
With "Do it twice", he adds an extra 6 steps to develop a prototype parallel to the simple waterfall model, with the goal to spot every unforeseen requirement prior to any actual development. |
|
|
|
|
|
|
|
|
|
|
|
Interestingly, the mentioned problems that \textcite{royce_managing_1970} is providing a solution for, are similar to the difficulties in this case study. |
|
|
|
|
|
Studies and publications about the waterfall model would have been far more relevant if the authors included Royce's improvements. |
|
|
|
|
|
Especially as Royce explains that in his experience, the method without his improvements has never worked and that recovery costs far exceeded the added cost of the proposed improvements. |
|
|
|
|
|
I expect that these improvements would have had a significant impact on the design process. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|