When evaluating Network Modeling, what aspect do you think is the most important to look for?

Who is using the network, what is their adaptability to new software? You can have a great network, redundancy, and fast server, but if your employees are not savvy, adaptable, or properly educated on the system then you'll lack synergy. You'll lose out big on ROI. Also, the customer's budget, connectivity requirements, mobility needs, and the end result should be considered. 

Separated view on the different parameters which are influencing the network.