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Chapter 3 Exercises 79

3.5. Explain why test-first development helps the programmer to develop a better understanding
of the system requirements. What are the potential difficulties with test-first development?
3.6. Suggest four reasons why the productivity rate of programmers working as a pair might be
more than half that of two programmers working individually.
3.7. Compare and contrast the Scrum approach to project management with conventional
plan-based approaches, as discussed in Chapter 23. The comparisons should be based
on the effectiveness of each approach for planning the allocation of people to projects,
estimating the cost of projects, maintaining team cohesion, and managing changes in
project team membership.
3.8. You are a software manager in a company that develops critical control software
for aircraft. You are responsible for the development of a software design support
system that supports the translation of software requirements to a formal software
specification (discussed in Chapter 13). Comment on the advantages and disadvantages
of the following development strategies:
a. Collect the requirements for such a system from software engineers and external
stakeholders (such as the regulatory certification authority) and develop the system
using a plan-driven approach.

b. Develop a prototype using a scripting language, such as Ruby or Python, evaluate
this prototype with software engineers and other stakeholders, then review the
system requirements. Redevelop the final system using Java.
c. Develop the system in Java using an agile approach with a user involved in the
development team.

3.9. It has been suggested that one of the problems of having a user closely involved with
a software development team is that they ‘go native’; that is, they adopt the outlook of
the development team and lose sight of the needs of their user colleagues. Suggest three
ways how you might avoid this problem and discuss the advantages and disadvantages
of each approach.
3.10. To reduce costs and the environmental impact of commuting, your company decides to
close a number of offices and to provide support for staff to work from home. However,
the senior management who introduce the policy are unaware that software is developed
using agile methods, which rely on close team working and pair programming. Discuss
the difficulties that this new policy might cause and how you might get around these
problems.