So far..
 We have covered
a) Requirements gathering: observation & interview.
b) Requirements specification.
c) Requirements validation.
d) Design/paper prototyping in this case.
e) Architecture.
f)
Effort analysis and scheduling.
OUTLINE
 Monday : design gallery (with modifications)
 Thursday: Meet with your consumers to present your
second design
 Final exam on Thursday 8/12/2010
Assignments:
 Monday - architecture assignment submission.
 Final submission: SR template (due Friday midnight
8/6/2010)
Today
 Scheduling and how to go about it.
As we saw in the previous lecture, there are basically
three kinds of costs that are normally associated in
projects.
a) Hardware costs
b) Training and travel cost
c) Effort cost
We also noted that effort cost was the most important
and hard to calculate. So we will focus on
calculating that today.
Different metrics
You could use any of the below techniques or a mix and match of them to
determine your effort cost and hence set a schedule.
• Algorithmic cost modeling
–
Base estimate on project size (lines of code)
• Expert judgment
–
Ask others
• Estimation by analogy
–
Cost based on experience with similar projects
Now that you have the architecture of the system, you are setting your
schedule for the development /implementation , testing phases of that
system.
You now ought to make some realistic analysis of what parts of it can be
implemented and what you might have to skip.
You are allowed to estimate the time period ( you just cannot say as long
as it takes, you must make a realistic estimation)
Productivity metrics
• Lines of code
– Simple, but not very meaningful metric
– Easy to pad, affected by prog language
– How to count revisions/debugging etc?
• Function points
– Amount of useful code produced (goals/requirements met)
– Less volatile, more meaningful, not perfect
Function points
Function points are computed by first calculating an
unadjusted function point count (UFC). Counts are made
for the following categories (Fenton, 1997):
–
–
–
–
–
External inputs – those items provided by the user that describe
distinct application-oriented data (such as file names and menu
selections)
External outputs – those items provided to the user that generate
distinct application-oriented data (such as reports and messages,
rather than the individual components of these)
External inquiries – interactive inputs requiring a response
External files – machine-readable interfaces to other systems
Internal files – logical master files in the system
Each of these is then assessed for complexity and given a
weighting from 3 (for simple external inputs) to 15 (for
complex internal files).
Unadjusted Function Point Count (UFC)
Weighting Factor
Item
Simple
Average
Complex
External inputs
3
4
6
External outputs
4
5
7
External inquiries 3
4
6
External files
7
10
15
Internal files
5
7
10
Each count is multiplied by its corresponding complexity
weight and the results are summed to provide the UFC
Object points
Similar to function points (used to estimate projects
based heavily on reuse, scripting and adaptation of
existing tools)
• Number of screens (simple x1, complex x2, difficult x3)
• Number of reports (simple x2, complex x5, difficult x8)
• Number of custom modules written in languages like
Java/C x10
Choosing the productivity metric
 Choose the most appropriate of the three and give a
reasoning on why you chose it.
a) Object points
b) Function points
c) LOC
Today’s activity
 Similar to the example in the previous lecture.
Follow the following steps:
 A) Draw an activity graph along with dependencies.
 B) Set milestones.
 C) Determine the person-month effort to reach each
milestone ( You can determine this in any way you
want to of the three methods: asking an expert,
making an estimation, or looking at similar previous
tasks)
Example Gantt chart
What I finally want!