This
is the case study that was to have been Part III of the PSARE book. For various
reasons we decided to publish the book without this case study, and principal
among those reasons was the rapidly changing state of software technology. The
H/H/P architecture method lends itself to the representation of software architectures
as well as system-level architectures, but with the rising popularity of the
UML, we felt it better to leave the mapping between H/H/P and the UML fluid
for the moment, and to involve a larger audience in the development of the mapping.
The Quick-Ticketing (QT) case study was deliberately chosen to be different from the Groundwater Analysis System (GAS) case study (in Part II of PSARE) in order to illustrate a system that is both user-interface-driven and software-intensive.
We will start out with an initial customer requirement statement that is typically vague and incomplete, and continue from there. We did have a fair amount of the case study worked out before deciding not to publish it, but our intent is not to bias you with our ideas, but to work this case study interactively with you, and to progressively capture the best ideas that come forth. We established the Discussion Forum for this purpose, and invite you to go there and express your views. We (the authors) will participate in the discussions, but we do not intend to drive it. This is meant to be a forum in the truest sense of the word — a place for collegial debate leading to a well-considered solution. So please go forth and debate among yourselves: we will chip in whenever we feel it is appropriate, and we will update the model likewise.
We will use Figure 6.1 A Roadmap for the System Specification Model from the PSARE book as our guide to the structure of the QT model, and will base the navigation of the model on that structure. Thus, the overriding structure will be that of the the system architecture, with the various requirements and detailed specifications grouped with their corresponding architecture modules.