Many people asked me the difference between Solution Architect and Enterprise Architect.   I found a good overview by Gabriel Morgan - Enterprise Architect vs Solution Architect - on msdn blog.  

I agree on most part that Enterprise Architect and Solution Architect  are complimentary roles and should interact in project delivery and long term strategic planning.  However, I don’t quite see in practice the role of the two architects play out as suggested by him (see quote below)

I propose that the Enterprise Solution Architect be involved at the earliest point a new business initiative is created and do very high-level ’solutioning’ via whiteboard and reference to future state architecture elements. Then, when the business initiative gains momentum is backed by Enterprise Architecture future state analysis the core project team is formed and the project Solution Architect takes over to be responsible for the solution. The Enterprise Solution Architect becomes a member of the project Solution Architects team and is responsible for the system integration architecture where the solution requires integration between enterprise systems as well as be responsible to provide future state system architecture guidance to help the project Solution Architect make decisions on which systems to commit to using in the solution. The Enterprise Solution Architect then is involved in governance boards to inform decision-makers with future-state architecture artifacts to help justify major technology, system, or business value decisions. That’s it.

I argue that Solution Architect is the mastermind, in business/project situations, orchestrating the activities of the various key supporting architects (Business Architect, Information Architect, Application Architect, Technical Architect, and Domain Architect e.g. Security) .   He is ultimately responsible for the delivery of stable, scalable and secured business services at the end of day.

The bucks stop here with the Solution Architect. He is a business transformer and is in a better position to sense the business pulse, trends and needs.  A great Solution Architect develops strong business acumen thanks to the understanding and trust he has with his business users.   

Enterprise Architect has to see the big picture, reducing systems complexity and applications redundancy.  He would be blind-sighted if he formulate his strategy by aligning only to a particular business. Hence he is not in the best position to set new directions for business solutions and services.

I also tend to believe in practice, Enterprise Architect is encouraged to “think inside the box“, limiting to the boundary of the enterprise framework. Whereas Solution Architect, in the name of business competitiveness, are allowed to “think outside the box“, and sometimes forgiven if this means breaking the rules of the architectural standards.