UML Weekend Crash Course™ - To Parent Directory

Session 2—UML and Development Methodologies 21
Programmers work extremely well together. In every shop I’ve worked in for over 20
years, programmers tend to be extremely individualistic and resist input from other
programmers. I’ve mediated too many fights to be overly optimistic in this area.
Experienced programmers work with new team members to maintain the system
(“Maintenance is the normal state of XP,” says Kent Beck). In every shop I know,
the experienced people move on to new projects and the new folks get stuck with
the maintenance. It’s almost like a rite of passage. Plus, in XP there is no documentation
other than in-line comments (that is, no overview documentation
about how the design works or how the system fits together), which makes it
extremely difficult to know how to modify a system.
Design is a skill that is common to every coder. Not so. Many programmers have
no concept of what good design is. Much of their coding is intuitive or simply
“how they learned to do it.”
Resources
The single best resource I’ve found to track down the various methodologies is www.cetus
links.org. On the first page of this site, you will find a link to OOAD Methodologies. Click
on it and you will be sent to a page with links to more than 50 different methodologies, lists
of books, articles, conferences, and organizations worldwide.
REVIEW
A methodology is made up of a predefined process, a vocabulary used to describe the process
and the work products, and a set of rules and guidelines that help define the quality of the
process and the work products. The UML specifies only the vocabulary, the notation that
describes the artifacts of the process. Each methodology decides if and how to apply the
UML notation.
This session presented four leading methodologies that illustrate the diversity and commonality
of the current techniques available for software development.
The Rational Unified Process (RUP) provides a comprehensive plan for the activities
and the artifacts required to complete the development process. The approach
strongly emphasizes iterative and incremental development. The RUP is best suited
for large projects.
The Shlaer-Mellor Method emphasizes tight integration and simulation to verify the
accuracy of the product throughout development. The Shlaer-Mellor Method is best
suited for real-time systems.
The CRC method emphasizes simplicity and role-playing to work out the class-level
requirements for the design of the system. The CRC method is best suited for helping
people learn about objects and object-oriented design.
Extreme Programming (XP) attempts to address many of the personal issues involved
in team dynamics and to create the most positive work environment for both programmers
and clients alike. It emphasizes continuous testing, consistent standards,
and a lot of communication throughout the process. XP tends to be best suited for
small, fast-moving projects with high management and client support.