Course Grained Access is a Granularity in a web service or component that requires clients to make very few 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 course grained access would have the client update the customer’s first name, last name, address, city, state, and zip in a single invocation by either passing all the items as arguments to a procedure or by passing an entire customer object as the argument.

As a general rule, course grained access is a good idea with web services since it minimizes the number of network round trips.

The main down side to Course Grained Access over Fine Grained Access is that creates rigidity in how clients work with the web service. For instance, if a client were redesigned so that a customer’s name was typically updated separately from address, city, state, and zip, then the client might still have to update the entire customer when only the name had changed.

See: Granularity