UML develops diagrams and provides users (programmers) with ready-to-use, expressive modeling examples.

What is a sequence diagram?

A sequence diagram is a type of interaction diagram because it describes how—and in what order—a group of objects works together.

What is the difference between a timing diagram and a sequence diagram in terms of representation?

The axes are reversed in the timing diagram and sequence diagram so that the time increases from left to right, and the lifelines are shown in separate compartments arranged vertically.

How many diagrams are there in UML?

It may seem as though there are infinite numbers of UML diagrams, but in actuality, UML standards identify 13 types of diagrams divided into two groups.

Table of contents

Introduction

Basic Elements of the Timing Diagram

2.1.

Lifeline

2.2.

State or Condition Timeline

2.3.

Duration Constraint

2.4.

Time Constraint

2.5.

Destruction Constraint

Example of Timing Diagram

Advantages of Timing Diagram

Disadvantages of Timing Diagram

FAQs

Key Takeaways

Last Updated: Mar 27, 2024

Timing Diagram

Author Apoorv Dixit

Introduction

By the name 'Timing Diagram,' one can easily relate to a diagram depicting the time or something similar. But in Software Engineering, they are specialized behavioral modeling diagrams used widely in object-oriented software design.

Source: tenor.com

Timing diagrams are part of UML. UML(Unified Modeling Language) is a modeling language that is most often used for software engineering but has extended its use to business processes and other project workflows. Talking about exact definition, “In UML, timing diagrams are interaction diagrams used to show interactions when the core logic of the diagram is to reason about time. The timing diagram focuses on the conditions changing within(or among) lifelines”.

Basic Elements of the Timing Diagram

The timing diagram depicts how an object underwent a change from one form to another with the passage of time. It consists of a graph or waves that represent the state of a lifeline at a specific point in time.

Timing diagrams have some major components they are explained below:

Lifeline

Lifeline depicts an entity( it represents only one entity), which is part of the interaction. It represents the classifier's name or the instance it portrays.

A lifeline can be placed within a diagram frame or "swimlane."

Source: UML-diagrams

State or Condition Timeline

These are continuous timelines. These are used in scenarios where entities undergo constant state changes, such as temperature or density. The condition and state timelines are used to represent the cooperation of attributes and classifier states.

Source: UML-diagrams

Duration Constraint

It is an interval constraint that refers to a duration interval. Duration interval is duration to determine whether the given condition is satisfied or not. The semantic of a duration constraint is inherited from a normal constraint(if the constraint is violated, trace becomes negative, and the system fails).

Duration constraint is depicted in the diagram below with the construct it constrains.

Source: UML-diagrams

Time Constraint

Time constraint is an interval constraint that refers to a time interval. It is a time expression that depicts if the constraint is satisfied or not. The semantic of a time constraint is inherited from a normal constraint(if the constraint is violated, trace becomes negative, and the system fails).

Time constraint is shown between a time interval and the construct it constrains.

Source: UML-diagrams

Destruction Constraint

Destruction constraint is a message occurrence representing the destruction of the instance described by the lifeline. No other occurrence can appear after the destruction event of a given lifeline.

Note: Destruction may result in the subsequent destruction of other objects that the parent object owns by composition.

Source: UML-diagrams

Also, read about V Model in Software Engineering

Example of Timing Diagram

An example of the timing diagram of the medical domain showing stages of fatal brain disease that causes memory loss, Alzheimer's disease, is shown below.

Source: UML-diagrams

Note: This is a UML diagram example and should not be considered as a medical reference for the disease.

The seven stages of Alzheimer's are shown in the above diagram, along with the duration of the stage. The environment is written in the top left corner(sd Alzheimer's Stages}, it tells what the diagram is about. Time duration is specified in { } (brackets).

Advantages of Timing Diagram

Timing diagrams keep track of every change that occurs in the system.
It explains the time processing of an object in detail.
The diagram easily explains the graphical representation of a lifeline state.
It describes the modification object bears in its form over the lifeline.
Various notations in the diagram helps to clarify a transition state between two lifelines.
It is employed with distributed and embedded systems.
Forward and reverse engineering can be implemented with it.

Disadvantages of Timing Diagram

Timing diagrams are hard to maintain.
One should learn all basic elements first to understand them better.

FAQs

What is UML?
UML(Unified Modeling Language) is a modeling language that is most often used for software engineering but has extended its use to business processes and other project workflows.
Why is UML used?
UML develops diagrams and provides users (programmers) with ready-to-use, expressive modeling examples.
What is a sequence diagram?
A sequence diagram is a type of interaction diagram because it describes how—and in what order—a group of objects works together.
What is the difference between a timing diagram and a sequence diagram in terms of representation?
The axes are reversed in the timing diagram and sequence diagram so that the time increases from left to right, and the lifelines are shown in separate compartments arranged vertically.
How many diagrams are there in UML?
It may seem as though there are infinite numbers of UML diagrams, but in actuality, UML standards identify 13 types of diagrams divided into two groups.

Key Takeaways

In this article, we learned about the Timing diagram. We also saw the characteristics and elements of timing diagrams. Later we discussed one example followed by its advantages/disadvantages.

You can refer to Object Diagram and Class Diagram to learn some more concepts of UML diagrams and software object design. You can also visit Coding Ninjas Studio for your complete interview preparation and land your dream job.

Happy Learning Ninja!