Fine Grained Access is a Granularity in a web service that requires clients to make many method invocations to get a single job done. For instance, if a typical client needs to update a single customer record, a web service based on fine grained access would have the client update the customer’s first name, last name, address, city, state, and zip in separate method invocations.

As a general rule, overly fine grained access and web services do not mix well since each method invocation requires Object Marshalling / Demarshalling. This creates a great deal of computing and network overhead that can degrade performance far more than the efficiency gained by sending a few small pieces of data.

The main plus side to Fine Grained Access over Course Grained Access is that it allows more flexibility in how clients work with the web service. For instance, it would more easily accommodate a redesign of the client meant that a customer’s name was typically updated separately from address, city, state, and zip.

See: Granularity