  Many prescriptive approaches to developing software intensive systems have
been advocated but each is based on assumptions about context. It has been
found that practitioners do not follow prescribed methodologies, but rather
select and adapt specific practices according to local needs. As researchers,
we would like to be in a position to support such tailoring. However, at the
present time we simply do not have sufficient evidence relating practice and
context for this to be possible. We have long understood that a deeper
understanding of situated software practices is crucial for progress in this
area, and have been exploring this problem from a number of perspectives. In
this position paper, we draw together the various aspects of our work into a
holistic model and discuss the ways in which the model might be applied to
support the long term goal of evidence-based decision support for
practitioners. The contribution specific to this paper is a discussion on model
evaluation, including a proof-of-concept demonstration of model utility. We map
Kernel elements from the Essence system to our model and discuss gaps and
limitations exposed in the Kernel. Finally, we overview our plans for further
refining and evaluating the model.
