The information in this chapter is based on my own experiences in security over the last nine years. Although I have used elements from different designs I have seen, none of these designs is real, for obvious reasons. Any similarity to your own network is purely coincidental. All these designs result in final topologies that are somewhat different from the sample designs in Chapters 13 through 15 to reinforce the idea that the designs in the previous chapters are examples, not answers.
The case study designs are certainly simplified. Budget and staffing information isn't a focus, nor is detailed risk analysis and security policy development. Documenting the complete security system development process just for one case study might fill a small book.