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The web tier consists of components that handle the interaction between clients and the business tier.

We now learn form the source that there is a 'business tier', and the interaction between the clients and the 'business tier' is handled by a 'web tier'. So the initial analysis model of interaction between the client and the 'middle tier' mentioned elsewhere needs refinement, in particular, it is not clear that the business functions directly serve clients (as previously indicated using a delegation Connector within *Tier_middle).

The interpretation offered here cautiously - with a «?» analysis stereotype - is that there is in fact a dedicated web interaction Interface called *Serve - qualified by a namespace - on the client side (indicated with a named Port), and another Interface called *Serve - likewise qualified by a namespace - on the business side (also indicated with a named Port).

Is the client-side *Serve provided by the web tier the same as (or subsitutable for) the *Serve that has until now been used ? For now it will be assumed that it is using a Generalization stereotyped by «?substitutable».

Previously the analysis assumed that the 'middle tier' owned the business functions directly; this has been weakened now with shared aggregation, and the possibility of the middle tier being decomposable into a web tier and business tier is indicated, with the business tier managing the business functions.

We are beginning to see the incredible power of the UML™ Parsing Analysis recipe as it converges towards a robust analysis model, driven by indications from the source text, with massive reuse of analysis.