Software Engineering
Lab Session
Session 4 – Feedback on Assignment 1
© Jorge Aranda, 2005
Overview

(Shorter) round of feedback on
Assignment 3

Assignment 4

PSP1

Results from Assignment 1

Note on tutorial next week
New insights/opinions to report?

Feedback on each aspect of the
assignment:





The actual programming task (no PSP)
The Project Plan Summary
Time and Defect Logs – any changes?
Other documents for the assignment
Impressions on the PSP in general
Assignment 4

Calculate the linear regression size-estimating parameters
for a set of n programs.
 What???


If you don’t understand these requirements, you probably
haven’t read the required chapters! You should have gone
all the way to Chapter 6 already. Go back and read them.
Section A7 will help as well.
Basic idea: To use the PROBE estimation method (more on
this later), you’ll need two parameters that you enter into a
formula.

Calculating them by hand is a pain

So we’re building a tool that will do that for us
Assignment 4

Assignment 4 uses PSP1

Very similar to PSP0.1, except because now we’re
attempting to have more solid estimates

You should have nailed down time and defect
tracking by now, so focus on getting the
estimation method right!
PSP1

Only big difference: Size Estimating Template and
the PROBE method



We won’t go over it all in this tutorial
Basic idea: if your estimates and your actual
performance are correlated, then finding the linear
regression factors between both data sets, and using
them for your new estimate, will produce more accurate
results
Until now, the only estimates we have produced are LOC
numbers and Estimated Time numbers.


We’ll start estimating the number of functions that our
program needs to work, but the advantages of these
estimates will only show up later in the process
Highly recommended that you follow tables C35 and C36
from the Humphrey book
Results from Assignment 1

In general, high marks: Average 83.9

Some of you have special marking notes (R1, T2, etc.)


Check Paul’s list of notes at
http://www.cs.toronto.edu/~jaranda/csc444/assig1notes.html
What to do if you’re unhappy?

First, cool down and check whether you’re sure we made a mistake

If you think your grade is incorrect, write a remarking request stating:


Your name and student number
Your case (why do you think your mark is incorrect?)

Give me your remarking request, along with your assignment, at the
start of our next tutorial session

Note that if you do this, the marking TA will remark your full
assignment.
Results from Assignment 1

Average estimate: 186 minutes


Perhaps because you were told one of these
assignments usually takes 2-4 hours?
Average real total time: 271 minutes

About 1.5 hours more than the average estimate

Average overrun: 58%

Average number of defects found: 9
Results from Assignment 1

Before you see the following charts,
REMEMBER:




You are not being marked for accuracy of
estimates
You are not being marked for actual time spent
You are not being marked for number of
defects found
This is not a programming competition
minutes
451+
421-450
391-420
361-390
331-360
301-330
271-300
241-270
211-240
181-210
151-180
121-150
91-120
61-90
31-60
0-30
Results from Assignment 1
Estimates
35.0%
30.0%
25.0%
20.0%
15.0%
10.0%
5.0%
0.0%
minutes
451+
421-450
391-420
361-390
331-360
301-330
271-300
241-270
211-240
181-210
151-180
121-150
91-120
61-90
31-60
0-30
Results from Assignment 1
Actual Times
35.0%
30.0%
25.0%
20.0%
15.0%
10.0%
5.0%
0.0%
minutes
451+
421-450
391-420
361-390
331-360
301-330
271-300
241-270
211-240
181-210
151-180
121-150
91-120
61-90
31-60
0-30
Results from Assignment 1
Estimates vs. Actual Times
35.0%
30.0%
25.0%
20.0%
15.0%
10.0%
5.0%
0.0%
250%+
[+220 +249%]
[+190 +219%]
[+160 +189%]
[+130 +159%]
[+100 +129%]
[+70 +99%]
[+40 +69%]
[+10 +39%]
[-19 +9%]
[-50 -20%]
<-50%
Results from Assignment 1
Overrun %
35.0%
30.0%
25.0%
20.0%
15.0%
10.0%
5.0%
0.0%
Results from Assignment 1
Average time percentage per phase
Postmortem
11%
Planning
8%
Design
9%
Test
25%
Code
38%
Compile
9%
Results from Assignment 1
Jorge's numbers
Student A Numbers
Postmortem
6%
Postmortem
4%
Planning
21%
Planning
5%
Design
0%
Code
20%
Test
32%
Design
9%
Compile
7%
Test
64%
Compile
0%
Code
32%
Student B Numbers
Student C Numbers
Planning
16%
Postmortem
13%
Planning
0%
Design
0%
Postmortem
41%
Code
37%
Test
14%
Compile
3%
Design
28%
Code
26%
Compile
4%
Test
18%
Results from Assignment 1
Number of Defects
60.0%
50.0%
40.0%
30.0%
20.0%
10.0%
0.0%
0
1-4
5-8
9-12
13-16
17-20
21-24
25-28
29-32
33+
Note on tutorial next week

Next week is the midterm, and during the tutorial
session there will not be new content

However, if you…


have read up to Chapter 6 of the book,
have tried to do the PSP1 estimation process on your
own,

… and still can’t work it out, I’ll be here 6-7pm to
help you find out if you’re doing something
wrong.

But no answers if you haven’t done your job!