The Unified Modeling Language (UML)- part 9

Timing Diagrams
UML timing diagrams are used to display the change in state or value of one or more elements over time. It can also show the interaction between timed events and the time and duration constraints that govern them.

State Lifeline
A state lifeline shows the change of state of an item over time. The X-axis displays elapsed time in whatever units are chosen, while the Y-axis is labelled with a given list of states. A state lifeline is shown below.

Value Lifeline
A value lifeline shows the change of value of an item over time. The X-axis displays elapsed time in whatever units are chosen, the same as for the state lifeline. The value is shown between the pair of horizontal lines which cross over at each change in value. A value lifeline is shown below.

Putting it all Together
State and value Lifelines can be stacked one on top of another in any combination. They must have the same X-axis. Messages can be passed from one lifeline to another. Each state or value transition can have a defined event, a time constraint which indicates when an event must occur, and a duration constraint which indicates how long a state or value must be in effect for. Once these have all been applied, a timing diagram may look like the following.

Interaction Overview Diagrams
An interaction overview diagram is a form of activity diagram in which the nodes represent interaction diagrams. Interaction diagrams can include sequence, communication, interaction overview and timing diagrams. Most of the notation for interaction overview diagrams is the same for activity diagrams. For example, initial, final, decision, merge, fork and join nodes are all the same. However, interaction overview diagrams introduce two new elements: interaction occurrences and interaction elements.

Interaction Occurrence
Interaction occurrences are references to existing interaction diagrams. An interaction occurrence is shown as a reference frame; that is, a frame with “ref” in the top-left corner. The name of the diagram being referenced is shown in the center of the frame.

Interaction Element
Interaction elements are similar to interaction occurrences, in that they display a representation of existing interaction diagrams within a rectangular frame. They differ in that they display the contents of the references diagram inline.

Putting it all Together
All the same controls from activity diagrams (fork, join, merge, etc.) can be used on interaction overview diagrams to put the control logic around the lower level diagrams. The following example depicts a sample sale process, with sub-processes abstracted within interaction occurrences.

This tutorial is collected from following Source:


2 Responses

  1. hello!
    i’m reading your articles about UML and I find them very interestng and well exposed…i mean more easy to read than UML superstructure specification :-)..
    I’ve two questions:
    1) do you think that UML is thought also to model processes that will be not implemented as software?
    2) do you think that UML can be used not only to model processes but also to describe existing processes to other users? what’s the scope? informatical only or others (bilogical for example)…?
    thank you very much

  2. Can I simply say what a relief to seek out somebody who actually is aware of what theyre talking about on the internet. You undoubtedly know tips on how to carry a problem to light and make it important. More individuals must learn this and perceive this side of the story. I cant consider youre not more widespread since you definitely have the gift.Useful infoipad

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