Page 43 - DCAP304_DCAP515_SOFTWARE_PROJECT_MANAGEMENT

Unit 1: Introduction to Software Project Management

How are software projects special? The authors speak of four qualities, viz. invisibility, Notes
complexity, conformity and flexibility. “With software, progress is not immediately visible”;
and “per dollar, pound or euro spent, software products contain more complexity than other
engineered artefacts.” To add to the woes of software creation, “Organisations, because of
lapses in collective memory, in internal communication or in effective decision-making,
can exhibit remarkable `organisational stupidity’ that developers have to cater for.” Software
is so easy to change; but flexibility is both a strength and source for trouble because “software
will change to accommodate the other components rather than vice-versa.”
Often projects fail because of faulty estimation of effort required. An over-estimate can
cause the project to take longer, because two laws come into play: Parkinson’s Law, that
work expands to fill the time available, and Brooks’ Law, that putting more people on a
late job makes it later! What happens if there is an underestimate? Your staff may respond
to deadlines with substandard work, and this is ‘Weinberg’s zeroth law of reliability’ in
action - “if a system does not have to be reliable, it can meet any other objective.”
A parametric model you’d read about in the book is COCOMO (short for COnstructive
COst MOdel). The basic equation is effort = c x sizek where effort is measured in pm, or the
number of ‘person-months’ consisting of units of 152 working hours, size is measured in
kdsi, thousands of delivered source code instructions, and c and k are constants. “Boehm
originally used mm (for man-months) when he wrote Software Engineering Economics,”
states the book, and that’s another book you can catch up with. Also, there is now a newer
version called COCOMO II, like a movie sequel. For Boehm, the constants depended on
the mode of the system, which was organic, embedded or semi-detached.
Take my suggestion: Better be attached to completing the software project because an
unfinished one is only a ticket to hell.

Thinking Hat for Red Hat
READ, practice and pass the test. Thus screams the cover of RHCE, Exam Study Guide by
Michael Jang, published by Dreamtech Press (www.wileydreamtech.com). The
abbreviation stands for Red Hat Certified Engineer Linux. “Major corporations, from
Home Depot to Toyota, and governments such as Germany, the Republic of Korea, and
Mexico have made the switch to Linux,” states the preface. “Major movie studios such as
Disney and Dreamworks use Linux to create the latest motion pictures.”

About the exam, the author cautions that it is a gruelling five-and-a-hour exercise (twice
the length of a world-class marathon). “The most important thing that you can take to the
exam is a clear head.”
Okay, it’s time for some teasers: Which of the following services works to connect Linux
to a Microsoft Windows-based network - NFS, SMB, DNS or Windows for Workgroups?
Which of the following commands would you use to write an ISO file to a CD - cdburn,
cdrecord, isorecord, or xcdrecord?

Some queries are detailed: “You are running an ISP service and provide space for users’
Web pages. You want them to use no more than 40MB of space, but you will allow up to
50MB until they can clean up their stuff. How could you use quotas to enforce this policy?
(a) Enable grace periods; set the hard limit to 40MB and the soft limit to 50MB; (b) Enable
grace periods; set the hard limit to 40MB and the soft limit to 50MB; (c) Enable grace
periods; set the soft limit to 40MB and the hard limit to 50MB; or (d) None of the above.”
Are there answers? Yes, in this problem, ‘c’ is the right answer because “this will warn
users they are over their limit after the grace period, but will make sure they do not exceed
the 50MB true maximum barrier.” Option `a’ is wrong because “the soft limit must be less
than the hard limit,” and `b’ is same as ‘a’. Option ‘d’ is incorrect because ‘c’ does the job.

LOVELY PROFESSIONAL UNIVERSITY 37