Page 16 - DCAP405_SOFTWARE_ENGINEERING

Unit 1: The Evolving Role of Software

Customer Myths Notes

A customer who requests computer software may be a person at the next desk, a technical group
down the hall, the marketing/sales department, or an outside company that has requested
software under contract. In many cases, the customer believes myths about software because
software managers and practitioners do little to correct misinformation. Myths led to false
expectations and ultimately, dissatisfaction with the developers.
Myth: A general statement of objectives is sufficient to begin writing programs we can fill in
details later.

Reality: Although a comprehensive and stable statement of requirements is not always possible,
an ambiguous statement of objectives is a recipe for disaster. Unambiguous requirements are
developed only through effective and continuous communication between customer and
developer.
Myth: Project requirements continually change, but change can be easily accommodated because
software is flexible.
Reality: It’s true that software requirement change, but the impact of change varies with the
time at which it is introduced. When requirement changes are requested early, cost impact is
relatively small.

!
Caution However, as time passes, cost impact grows rapidly – resources have been
committed, a design framework has been established, and change can cause upheaval that
requires additional resources and major design modification.

Self Assessment

Fill in the blanks:
7. Software development is not a ……………………….. process like manufacturing.
8. Project requirements continually……………………..…... but change can be easily
accommodated because software is flexible.

9. A general statement of ………………………. is sufficient to begin writing programs we
can fill in details later.

1.4 Software Crisis

1. Size: Software is becoming larger and more complex with the growing complexity and
expectations out of software. For example, the code in consumer products is doubling
every couple of years.

2. Quality: Many software products have poor quality, i.e., the software produces defects
after put into use due to ineffective testing techniques. For example, Software testing
typically finds 25 defects per 1000 lines of code.

3. Cost: Software development is costly i.e., in terms of time taken to develop and the money
involved. For example, Development of the FAA’s Advance Automation System cost over
$700 per line of code.
4. Delayed delivery: Serious schedule overruns are common. Very often the software takes
longer than the estimated time to develop which in turn leads to cost shooting up. For
example, one in four large-scale development projects is never completed.

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