You may want to incorporate equipment and serviceprovider information from your evaluations into the blueprints and component plans. Thus, the network layout is usually the last part of the design process. We now examine each part of the design process in detail. 10.4 Vendor, Equipment, and ServiceProvider Evaluations The evaluation process presented here can be applied to vendors and service providers, their equipment and services. In general, this process consists of using products from network analysis and architecture to develop an initial set of options (termed seeding the evaluation process); conducting discussions to develop a complete set of candidate options, along with criteria to evaluate those options; gathering and developing data to apply to the evaluations; refining evaluation criteria and developing ratings; applying criteria and ratings to prioritize the candidate options; and modifying the set of candidate options, with the goal of selecting the optimal candidate. This process is shown in Figure 10.6. 396 CHAPTER 10 Network Design Candidate Discussions 1) Candidate A 2) Candidate B ... Initial Candidates 1) Criteria 1 2) Criteria 2 3) Criteria 3 ... Evaluation Criteria Criteria Refinement Data Gathering Ratings Development Refined Criteria 1) Criteria 1 2) Criteria 2 3) Criteria 3 ... Weights 0.1 0.5 1.0 ... Ratings and Prioritization Prioritized Candidates 1) Candidate D 2) Candidate A 3) Candidate C 4) Candidate B ... Modifying the Set of Candidates Architecture Products Reference Architecture Selected Technologies Equipment TypesClasses Selected Candidate(s) Seeding the Process 1) Candidate A 2) Candidate B ... Initial Candidates Candidate D FIGURE 10.6 Vendor, Equipment, and ServiceProvider Evaluation Process This is an iterative process. There are times when an optimal candidate can be found with a single iteration of the process; at other times it may take two or three iterations to produce an optimal result. The number of iterations depends in part on the complexity of the evaluations, how well prepared you are, and how well you and your evaluation team perform the evaluation. As you get used to the process, you will be able to get results with fewer iterations. Ideally, a template can be developed that can then be applied to each and every evaluation, making the process straightforward, predictable, and reproducible. That is what this section strives to provide. However, we also recognize that, depending on the project, some evaluations may have their own unique characteristics. In all cases I have found that this process can still provide excellent results. Although this process can be applied to evaluate vendors, vendor equipment, and service providers, it is important to note that we do not want to combine these evaluations into one. Keep each evaluation separate-do not mix vendors, vendor equipment, and service providers-as this will confuse the evaluators and overly complicate the process.