Information System Development Life Cycle Models - High Level Models and Methodologies for Information Systems - page 35

Fig. 2.8 The star life cycle model (adapted from Stone et al. 2005 )

project, with the possibility of going back over a given stage numerous times or
completely skipping another stage if it proves irrelevant. Thus, for example, a
developer might start by experimenting with various design options and, in that
process, learning more speci

c requirements of the project (Helms 2001 ).
The fundamental rule behind this premise is that each stage must be accompa-
nied by extensive evaluation. All the stages are interrelated, and in the development
process, it is possible to shift to any of them at any point, just as long as that stage is
evaluated. Likewise, each action that is completed, regardless of its order, has to be
thoroughly analyzed. This includes extensive testing and data collection on that
particular activity, through such methods as interviewing users or observing their
use of the system within the working context (Stone et al. 2005 ) (Fig. 2.8 ).
Users are positioned at the center of the development cycle and are encouraged
to participate in any of the stages: at the beginning of the process, to help establish
the system ne their goals and needs; during prototyping, to

ensure thorough testing under working conditions; before

' s requirements and de

final release, again to

provide extensive testing; and after the system s delivery, to monitor any possible

issues and communicate their overall experience with the system (Stone et al.
2005 ). This perspective clearly derives from the star model

'

s close relationship with
user interface design, as it was originally conceived within that particular context.
The model is laid out like a star, hence its name. Evaluation is at the center of the
star, since it is the fundamental premise that will guide all other steps. Around the
central step, we

'

find the different possible stages of development; however, they are
not connected to each other. This does not mean that there is no relationship
between the different stages; what it does illustrate is that every step is intercon-
nected through the process of evaluation (Helms 2001 ).