--- 02/assignment2.tex 2003/12/12 16:00:22 1.8 +++ 02/assignment2.tex 2003/12/13 21:04:39 1.11 @@ -170,7 +170,7 @@ that while good estimations on use case level can be made using this suit, it is not a good thing to try to make estimations of the system as a whole only based - on this information. + on this information. \\ \\ \textbf{Measuring designs} \subsection{Measure the class diagram presented in Design 1 using the CK metrics suite presented on the lecture.} @@ -186,15 +186,33 @@ See appendix c. \subsection{Write a short section (up to ½ page) with answers to the following questions:} - \begin{itemize} - \item Which of the metrics could not be computed based on the class - diagrams? Why? - \item Which of the two systems is more complex? Why? - \end{itemize} - Svar + \subsubsection{Which of the metrics could not be computed based on the class diagrams? Why?} + The LCOM (Lack of Cohesion in Methods) metric could + not be computed from the class diagram because LCOM metrics + are gathered through counting the number of + method-pairs that have no attributes in common and + then subtract the number of pairs that do have + common attributes. This can not be seen when looking + at the class diagram so you have to look at the + code to compute it. It would probably be quite handy + with a tool that computes this metric automatically + since it is very time consuming to do by hand. + \subsubsection{Which of the two systems is more complex? Why?} + Since Design2 has a lower total LCOM value (140 vs + 93) it is therefore considered more complex. + We draw this conclusion from the lecture and slides about CK metrics, a class + with low cohesion is ``hard to comprehend, hard to + reuse, hard to maintain and constantly effected by + change'' \subsubsection{Which method of gathering metrics - from UML designs or source code - is less time consuming?} - svar + You get a much better overview of the system when + looking at the UML design and it is much less + time consuming than searching through source code after source code to + find inheritance, number of children and so on. Some + metrics require going through source code though, so you + can not get everything from the UML designs, although it + would have been handy if it was possible. \section{External product attributes} \subsection{Describe how the external product attributes differ from the internal ones. Describe the connection between external and