A well-structured model with time and space properties
Exposes only those time and space properties that are necessary and sufficient to capture the desired behavior of the system.
Centralizes the use of those properties so that they are easy to find and easy to modify.
When you draw a time or space property in the UML,
Give your timing marks (the names of messages) meaningful names.
Clearly distinguish between relative and absolute time expressions.
Show space properties only when it's important to visualize the placement of elements across a deployed system.
For more advanced needs, consider the
UML
Profile for Schedulability, Performance, and Time . This OMG specification addresses the needs of real-time and high-performance reactive systems.