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2.2. Review of Existing Development Processes
15
2.2.2 Software Design Methodologies
Software design methodologies di er from software engineering processes as they
mainly focus on a subset of requirements during the development process, the soft-
ware user-interface. Accordingly, all of these methodologies have a strong user focus.
Some of them also go beyond the users’ articulated needs and incorporate empirical
findings about the anatomy of well-designed interfaces. Generally, however, develop-
ers derive requirements from the user but do not necessarily work together with the
user, as user-centered design (see Section 2.2.4) does. There exists quite an amount
of di erent software design methodologies which propose di erent rules, criteria, and
lists to follow on. However, to compare methodologies it can be di cult to decide
why one list may be more useful than others or how they are related. We also found,
that the pervasiveness of a methodology also correlates with the prominence of its
authors in the software design community.
Gould’s Methodology. The main focus of this approach
[
Gould 1995
]
is usability.
The approach is very informal and provides checklists that can be used in planning
and carrying out a project. Checklist items include talks with users, visits of cus-
tomer locations, simulations, early prototyping, try-to-destroy-it contests, follow-up
studies, and the consideration of all aspects of usability in the initial design. This
shows a very strong focus on the user but, as such, also a strong dependency on the
user: this method suggests exploratory sessions with users but stimulation of the
user leading to radically new ideas is not a goal. According to this approach, design
occurs in four phases: (1) A gearing-up phase, (2) An initial design phase, (3) An
iterative development phase, and (4) A system installation phase. A feasible result
is a declared goal of this method.
Xerox Systems Development Division Methodology. This methodology was
derived from the experiences during the development of the Xerox Star software
interface
[
Baecker et al. 1995
]
. It includes four phases: (1) Analyze what tasks
the user will want to do and the steps they go through to accomplish the tasks,
(2) Design an intended user model in terms of which tasks may be cast, (3) Design
a command language to make that model work, and (4) Design an information
display to reflect the operations of the system in terms of the conceptual model.
This methodology explicitly focuses on the early development phases and as such
has a continuing focus on the user. It aims to keep the design simple, consistent,
and clear enough for users to grasp. The methodology is not systematic and bound
to explicit single development steps but gives informal suggestions. Similar to the
previous method also the Xerox method does not aim at stimulating the users’ minds
to create innovative solutions but at solving users’ needs as they are articulated.
Rubinstein and Hersh’s Methodology. This approach
[
Rubinstein and Hersh
1984
]
includes 93 design principles and is composed of five successive stages. Within
each stage an iterative process is performed. The five stages are: (1) Information
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