24 |
These three supplements each other adding references to |
These three supplements each other adding references to |
25 |
each other. None of these is useful by itself, but by |
each other. None of these is useful by itself, but by |
26 |
adding them up one can get a better perspective of the |
adding them up one can get a better perspective of the |
27 |
size of the software. |
size of the software. The length itself don't tell |
28 |
|
anything of how large the completed software will be, but |
29 |
|
together with functions and complexity one can understand |
30 |
|
the size of the software. Once the size of the software is |
31 |
|
established one may come with effort estimations, and |
32 |
|
based on those make a budget for what resources the |
33 |
|
project will need. Given these three it is possible to get |
34 |
|
an idea of how productive a programmer is during a time |
35 |
|
unit. It will not be a perfect answer, but it will be |
36 |
|
something that could be used to measure deviations in work |
37 |
|
etc. |
38 |
\subsection{Give an example where code length measure can be useful and an |
\subsection{Give an example where code length measure can be useful and an |
39 |
example where source code length measure is not useful.} |
example where source code length measure is not useful.} |
40 |
svar |
Code length is useful if it is not going to be used by |
41 |
|
itself. One example of this could be if we are interested |
42 |
|
in how much work is done in a week. Then we could look at |
43 |
|
loc, and also take into account the complexity and the functions provided |
44 |
|
(like loc * complexity / functions or something similar). |
45 |
|
Then loc could be useful. |
46 |
|
|
47 |
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Code length is useless if it is used by itself. For |
48 |
|
example the statement I am a good programmer since I |
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|
produce more then n loc per week useless. |
50 |
\subsection{Explain what are the main ideas behind Albrecht's Function Points. |
\subsection{Explain what are the main ideas behind Albrecht's Function Points. |
51 |
Discuss advantages and disadvantages of the measure. Motivate.} |
Discuss advantages and disadvantages of the measure. Motivate.} |
52 |
svar |
%denna var bra http://www.spr.com/products/function.htm |
53 |
|
The main idea behind FP's are to provide language |
54 |
|
independent metric that can be used no matter what |
55 |
|
language are used. Albrech thought it was wrong that the |
56 |
|
only way to tell effort and cost per effort until he begun |
57 |
|
was in loc. A often used metric to tell productivity was |
58 |
|
cost/loc, and that don't tell anything since different |
59 |
|
languages require different number of loc's to solve the |
60 |
|
same problem. This cost could be lover if the language |
61 |
|
requires a lot of code, but the end cost could still get |
62 |
|
higher if the program takes longer time to complete. |
63 |
|
The main idea behind FP's is to give ways to |
64 |
|
tell cost and productivity in a way that is language |
65 |
|
independent. FP's does satisfy this idea. A easier |
66 |
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language will get a lower cost/FP and a greater number of |
67 |
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FP's/person\&month then a more complex language. |
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|
|
69 |
|
The great advantage with this method is that it is (almost) truly |
70 |
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language independent, while a disadvantage would be that |
71 |
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if this is established in the beginning of a project and |
72 |
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should be used to choose a appropriate language to use, if |
73 |
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the language is unfamiliar, then these metrics can't be |
74 |
|
computed (like FP's/person\&month). Also this way of presenting |
75 |
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the result does not take into account training and |
76 |
|
inexperience while showing the result. Also this should |
77 |
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not be used to compare different projects or groups to se |
78 |
|
the difference between them since this does not take |
79 |
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everything into account. Also one might be tempted to |
80 |
|
always use the language with the highest productivity, |
81 |
|
this is good in most cases, but sometimes there are other |
82 |
|
factors to sum in, like speed, security etc. |
83 |
\subsection{Describe structural measures presented by Fenton. (Control flow |
\subsection{Describe structural measures presented by Fenton. (Control flow |
84 |
structure, Data flow structure, Data structure). Give an example |
structure, Data flow structure, Data structure). Give an example |
85 |
where you explain how one could use the structural measures |
where you explain how one could use the structural measures |
86 |
(specify which structural measure) to ensure the quality of the |
(specify which structural measure) to ensure the quality of the |
87 |
software product.} |
software product.} |
88 |
svar |
%http://sern.ucalgary.ca/~kliewerc/SENG/623/summaries.htm#sum02 var lite halvbra... det bästa jag kunde hitta dock, + F4... |
89 |
|
Control flow is a diagram with nodes, connected via the |
90 |
|
directed connections showing the possible routs the |
91 |
|
program (or actually the flow of data in the program) may |
92 |
|
take. This could be broken down to several diagrams if it |
93 |
|
gets to large and complex. This diagram can be used to |
94 |
|
decide how many test cases is needed to test the program |
95 |
|
completely. |
96 |
|
|
97 |
|
The data flow structure could be shown in a module-call |
98 |
|
graph. The module-call graph shows what modules calls what |
99 |
|
other modules, and thereby showing more the flow of |
100 |
|
information within the program. This may also be used to |
101 |
|
show coupling and cohesion in the program. |
102 |
|
|
103 |
|
The data structure can be measured both locally and |
104 |
|
globally. Locally it is interesting how much data |
105 |
|
structure each data item has, and globally it is the |
106 |
|
amount of data for the system. For the local data |
107 |
|
structures very little research has been done, but for the |
108 |
|
global there are more. |
109 |
\subsection{Draw the flow graph for the program, which |
\subsection{Draw the flow graph for the program, which |
110 |
based on the data provided by everyday measurements of the air |
based on the data provided by everyday measurements of the air |
111 |
temperature will calculate the maximum, minimum and the most |
temperature will calculate the maximum, minimum and the most |
112 |
commonly occurred temperature (the temperature that occurs twice |
commonly occurred temperature (the temperature that occurs twice |
113 |
or more) for a given month. Present program paths that has to be |
or more) for a given month. Present program paths that has to be |
114 |
executed in order to satisfy the following testing strategies:} |
executed in order to satisfy the following testing strategies:} |
115 |
|
See appendix a for the diagram. |
116 |
\subsubsection{Statement coverage} |
\subsubsection{Statement coverage} |
117 |
svar |
a-b-c-d-e-f-g-h-i-j-k-l-m-n |
118 |
\subsubsection{Branch coverage} |
\subsubsection{Branch coverage} |
119 |
svar |
a-b-c-d-e-f-g-h-i-j-k-l-m-n \\ |
120 |
|
a-b-c-b-c-d-e-g-i-j-k-m-n \\ |
121 |
|
a-b-c-d-e-f-g-h-i-j-k-l-m-k-m-n \\ |
122 |
\subsubsection{Visit each loop} |
\subsubsection{Visit each loop} |
123 |
svar |
%osäker på om detta är rätt...jag har bara antagit att man skall göra ett test så att man kör alla looparna |
124 |
|
a-b-c-b-c-d-e-f-g-e-f-g-h-i-g-h-i-j-k-l-m-k-m-n |
125 |
\subsection{Calculate the cyclomatic complexity of your program. What does |
\subsection{Calculate the cyclomatic complexity of your program. What does |
126 |
this figure tell you?} |
this figure tell you?} |
127 |
svar |
%Cyclomatic complexity (CC) = E - N + p |
128 |
|
%where E = the number of edges of the graph |
129 |
|
%N = the number of nodes of the graph |
130 |
|
%p = the number of connected components |
131 |
|
%http://www.sei.cmu.edu/str/descriptions/cyclomatic.html |
132 |
|
Hopefully you mean McCabe's cyclomatic complexity\\ |
133 |
|
% e = no of arcs | n = no of nodes |
134 |
|
e-n+2 | 18 - 14 + 2 = 18 - 16 = 2 \\ %men vad säger nu detta |
135 |
|
This tells us the number of tests we have to do to cover |
136 |
|
each path in the program. It could also be used to give a |
137 |
|
estimation of how complex the final software will be. If |
138 |
|
higher then 20 it should be seen as a high risk project, |
139 |
|
and if higher then 50 as a very high risk project. %nuffrorna kommer från http://www.sei.cmu.edu/str/descriptions/cyclomatic.html |
140 |
\section{OO metrics} |
\section{OO metrics} |
141 |
\textbf{Measuring the use cases} |
\textbf{Measuring the use cases} |
142 |
|
%vi skall använda templaten, och bifoga denna... |
143 |
\subsection{Measure the use case specifications shown in Design 1 using the |
\subsection{Measure the use case specifications shown in Design 1 using the |
144 |
chosen use case metrics suite from the lecture} |
chosen use case metrics suite from the lecture} |
145 |
svar |
svar |
154 |
\subsubsection{Which of the two systems can be expected to require more |
\subsubsection{Which of the two systems can be expected to require more |
155 |
effort to be built? Why?} |
effort to be built? Why?} |
156 |
svar |
svar |
157 |
\textbf{Measuring designs} |
\\ \\ \textbf{Measuring designs} |
158 |
\subsection{Measure the class diagram presented in Design 1 using the CK metrics suite presented on the |
\subsection{Measure the class diagram presented in Design 1 using the CK metrics suite presented on the |
159 |
lecture.} |
lecture.} |
160 |
svar |
svar |
181 |
\subsection{Describe how the external product attributes differ from the |
\subsection{Describe how the external product attributes differ from the |
182 |
internal ones. Describe the connection between external and |
internal ones. Describe the connection between external and |
183 |
internal product attributes.} |
internal product attributes.} |
184 |
svar |
The internal attributes can be measured from within the |
185 |
\subsection{Assume that you are |
system (like loc etc) while for the external attributes |
186 |
working at the company that mainly specializes on developing of |
one must look at the finished product to se the external |
187 |
web-based applications. Your manager gives you an assignment to |
attributes. Also in general internal attributes are |
188 |
develop a software quality model for the company. The model should |
considered easier to measure (and then predict) then the |
189 |
show external quality attributes, corresponding internal |
external attributes. |
190 |
attributes and metrics. Present the assumptions that you will use |
|
191 |
while creating of the quality model. Provide an explanatory text |
This is partly since the internal attributes can be |
192 |
|
measured more ``directly'' then the external. For |
193 |
|
instance loc is easy to count while usability is a lot |
194 |
|
harder to measure. For the internal attributes one can |
195 |
|
expect to be able to get absolute values while on the |
196 |
|
external attributes one can expect them to be less |
197 |
|
accurate. |
198 |
|
|
199 |
|
However several of the internal attributes (if not all) |
200 |
|
does affect the external attributes in a way that can |
201 |
|
(in most cases) be predicted. One can for instance say |
202 |
|
that in a specific solution if the loc is increased |
203 |
|
(both with comments) then one could expect to get a |
204 |
|
higher maintainability. Also most of the external |
205 |
|
attributes can be affected via the internal if the |
206 |
|
developers keep the external attributes in mind. |
207 |
|
|
208 |
|
In most cases (if not always) the customer of the product |
209 |
|
is more interested in the external attributes. Does this |
210 |
|
mean that the external attributes are of ``greater'' |
211 |
|
value to the team developing the product? |
212 |
|
|
213 |
|
Not always but in many cases. Also one should keep in |
214 |
|
mind that just because the external attributes are more |
215 |
|
important that the internal could be forgotten. |
216 |
|
%\subsection{Assume that you are working at the company that |
217 |
|
%mainly specializes on developing of web-based applications. |
218 |
|
%Your manager gives you an assignment to develop a software |
219 |
|
%quality model for the company. The model should show external |
220 |
|
%quality attributes, corresponding internal attributes and |
221 |
|
%metrics. Present the assumptions that you will use while |
222 |
|
%creating of the quality model. Provide an explanatory text |
223 |
|
%for your model.} %Jag tyckte inte om att läsa den texten;) |
224 |
|
\subsection{Assume that you are working at a company that |
225 |
|
mainly specializes in development of web-based applications. |
226 |
|
Your manager gives you an assignment to develop a software |
227 |
|
quality model for the company. The model should show external |
228 |
|
quality attributes, corresponding internal attributes and |
229 |
|
metrics. Present the assumptions that you will use while |
230 |
|
creating the quality model. Provide an explanatory text |
231 |
for your model.} |
for your model.} |
232 |
max 8 sidor |
Assumptions: We are using an iterative development |
233 |
|
process, we are using function points to measure progress, |
234 |
|
we are using a good configuration management tool, we are |
235 |
|
identifying risks before starting a project, we are, but |
236 |
|
not always using uml for our projects. |
237 |
|
|
238 |
|
Since we are working on web-based applications we also |
239 |
|
assumed that we are selling those to a customer. This made |
240 |
|
us make a value based quality view. This made us decide |
241 |
|
that usability, lernability, reusability, maintainability, reliability, |
242 |
|
is the most important external attributes. The internal |
243 |
|
attributes are not considered as important, other than to |
244 |
|
help up the external. Customer satisfaction does supersede |
245 |
|
this thou. The external attributes has the following |
246 |
|
impact on customer satisfaction: \\ |
247 |
|
\begin{tabular}{|l|l|l|} |
248 |
|
\hline |
249 |
|
Attribute & Importance & Role \\ \hline |
250 |
|
Usability & High & |
251 |
|
Decides if the customer fells that he may use\\ |
252 |
|
& & the product or not. The more usable the product\\ |
253 |
|
& & becomes, the higher value it gets (and thereby\\ |
254 |
|
& & higher quality). \\ \hline |
255 |
|
%hmmm, borde finnas nått bättre sätt... |
256 |
|
Learnability & High & |
257 |
|
The quicker the end-user can learn to use the \\ |
258 |
|
& & program, the quicker he feels the value of the\\ |
259 |
|
& & program and does need it. This makes the \\ |
260 |
|
& & customer feels a gain from buying our product \\ \hline |
261 |
|
Reusability & Medium & |
262 |
|
This is only important if using agreements like\\ |
263 |
|
& & ``avtal 90'' or similar that gives us the freedom\\ |
264 |
|
& & of the developed artifacts, and may use them in\\ |
265 |
|
& & projects to come. If the customer has no demands\\ |
266 |
|
& & on this, and will own the artifacts then it is \\ |
267 |
|
& & not taken into consideration.\\ \hline |
268 |
|
Maintainability & Medium & |
269 |
|
This is only important if we are using the \\ |
270 |
|
& to low & |
271 |
|
reusability from above. And only to support that\\ |
272 |
|
& & purpose. Otherwise this would not have been a \\ |
273 |
|
& & issue at all. \\ \hline |
274 |
|
Reliability & High & |
275 |
|
This is important since a reliable program is \\ |
276 |
|
& & seen as having a higher value. \\ \hline |
277 |
|
\end{tabular} \\ \\ |
278 |
|
Internal attributes are only important in order to gain |
279 |
|
the external attributes. |
280 |
\end{document} |
\end{document} |