Timing Diagram

What is the timing diagram? Examples of the diagram.


What is the Timing Diagram?

Elements used in the timing diagram?

Examples of timing diagram wit description?

Why is the need to use a timing diagram?



Timing Diagram



Timing diagram:

This diagram is a UML interaction diagram. When the purpose of a diagram is to reason about the time, it is used to show interactions. This diagram focuses on the changing conditions within and between the lifelines. This diagram is used to describe the behavior of both classifiers. These classifiers are individual classifiers and interactions of classifiers.

This diagram is a special form of a sequence diagram. There is a difference between This diagram and sequence diagram. The difference is graphical. The difference is that the dimension This diagram is horizontal. The time increases from left to right. The lifelines are shown in separate compartments which are arranged vertically.

This diagram includes elements like messages, timeline, lifeline, and object. The object is also called a role.



Elements in timing diagram:

Here is a diagram of elements used in this diagram


timing diagram symbol

Following terms help in making this diagram. In short, these are components of this diagram


It is a named element. It represents an individual participant in the interaction. The lifeline represents only ONE interacting entity. Lifeline in this diagram is represented by the name of a classifier. It can also be represented by the instance it represents.



State / Condition timeline:

Here is the first symbol. This diagram shows states of the following-

  • Participating classifier
  • Participating attribute
  • Some testable conditions

UML allows the state dimension to be continuous.



Duration constraint

Here is a second symbol. It is an interval constraint. It refers to a duration interval. The duration interval determines whether the constraint is satisfied or not.



Time constraints

The third symbol for this diagram. It is an interval constraint. It refers to a time interval. A time interval is time expansion. It is used to determine whether the constraint is satisfied or not. The time constraint’s semantics is inherited from constraints. The traces where the constraints are violated are negative traces.


Destruction occurrence

Last symbol fo this diagram. It is a message occurrence. It represents the destruction of the instance which is described by the lifeline. No other occurrence appears after the destruction event on a given lifeline.


You can read about the use case diagram. Click on below

Use Case Diagram


Timing diagram examples:

Example #1 – Boat manufacturing

In this simple and easy example of a boat manufacturing diagram, the diagram is showing that too much time is spent on the upholstery stages of production. The factory administrators may need to assign more employees which is not good. If this diagram is used effectively to increase efficiency, the process can be improved. It will decrease the time and money both which will be spent on the process.




Timing Diagram



Example #2 – Stages of Alzheimer’s disease

Here is a diagram of a stage of Alzheimer’s disease. In which we will tell you about all the stages with respect to the time interval.


Timing diagram of Alzheimer's disease

The need to use timing diagram

When the machine cycle is executed, this diagram provides information about the various conditions of signals. The signal’s conditions may be low or high. It is not possible to match the peripheral devices to microprocessors without the knowledge of this diagram. This is one of the basic reasons that a diagram is important.



You can read many other articles. Names are given below. You can get all the detail about these topics.e.g

introduction, history, types, symbols, examples, working, advantages and disadvantages. Everything is available on this website. You have to visit different pages and posts on this website.

Communication diagram

Activity Diagram