«block» Operation vs. Reception

A SysML «block» may own behavioral features as well as structural features. SysML defines two types of behavioral features, operations and receptions.

An operation is «block» behavior that is requested synchronously, which means that the requester waits for a response to their behavioral request. Operations have a name (e.g., myOperation) and a return type (e.g., Real). Optionally, an operation may have a method applied which is defined by a SysML «activity». Operations may also have parameters which are categorized as in, out, inout, or return. Each operation parameter should have a type (e.g., Real) assigned as well.

A reception is «block» behavior that is requested asynchronously, which means the requester does not wait for a response to their behavioral request. Like an operation, the reception may also have parameters. Each reception is defined by a signal, whose attributes must match any reception parameters defined on the «block». Attributes may have a multiplicity. Signals may be used by more than one reception on one or more blocks.

Reference:

Friendenthal, S., Moore, A., & Steiner, R. (2012) A Practical Guide to SysML. Waltham, MA: Morgan Kaufmann.