Also check out this complete Sequence Diagram Tutorialto learn more about sequence diagrams. This is something that is used when you need to model a repetitive sequence. Lifelines are representative of roles or object instances that partake in the sequence being modeled. To draw a guard on a sequence diagram, you placed the guard element above the message line being guarded and in front of the message name, as shown below. It depicts the objects and classes involved in the scenario and the sequence of messages exchanged between the objects needed to carry out the functionality of the scenario. It encapsulates the system's functionality by incorporating use cases, actors, and their relationships. Are you looking for a Free UML tool for learning UML faster, easier and quicker? We and our partners use cookies to Store and/or access information on a device. the interaction that takes place in a collaboration that either realizes a use case or an operation (instance diagrams or generic diagrams), high-level interactions between user of the system and the system, between the system and other systems, or between subsystems (sometimes known as system sequence diagrams), Model high-level interaction between active objects in a system, Model the interaction between object instances within a collaboration that realizes a use case, Model the interaction between objects within a collaboration that realizes an operation, Either model generic interactions (showing all possible paths through the interaction) or specific instances of a interaction (showing just one path through the interaction), The horizontal axis shows the elements that are involved in the interaction, Conventionally, the objects involved in the operation are listed from left to right according to when they take part in the message sequence. A message defines a particular communication between Lifelines of an Interaction. You can define parameters and a return value. Sequence diagrams are organized according to time. UML Sequence Diagrams are interaction diagrams that detail how operations are carried out. Lifelines, Messages and Guards) that were related to Sequence Diagrams. Sequence diagram: used to surround an entire sequence diagram. 1. When modeling object interactions, there will be times when a condition must be met for a message to be sent to an object. A note (comment) gives the ability to attach various remarks to elements. It is a graphical representation of an electronic circuit that represents electrical components and their connections through the use of standardized symbols. PART 2: What type of UML diagram should you be using? If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page. Sequence Diagram is an interaction diagram that details how operations are carried out -- what messages are sent and when. a type of role played by an entity that interacts with the subject (e.g., by exchanging signals and data). 3 What are the basic elements of a sequence diagram? A sequence diagram is an essential component used in processes related to analysis, design and documentation. It is one of the standard languages to deal with the relational database. A sequence diagram is a type of interaction diagram because it describes howand in what ordera group of objects works together. The focus is more on the order in which messages occur than on the message per se. 6 Is there a visual paradigm for sequence diagram? A sequence diagram shows an implementation of a scenario in the system. Call message is a kind of message that represents an invocation of operation of target lifeline. Which security method can be used to secure the management plane within a network device? Visual Paradigm Online is free * and intuitive. Ltd. All rights reserved. We include a guard for the option; however, the guard is not a required element. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Copyright 2008-2022 Cinergix Pty. These can help to predict how a system will behave and to discover responsibilities a class may need to have in the process of modeling a new system. An example of data being processed may be a unique identifier stored in a cookie. It's target points to an activation on top of the activation where the message was invoked from. example, lifelines in a sequence diagram for a banking scenario can represent a customer, bank teller, or bank manager. What are the basic elements of a sequence diagram? PART 2: What type of UML diagram should you be using? Introduction to Sequence diagram Sequence diagram is interaction diagram that shows the set of objects and messages send and receive by those object. Focus of control: also called execution occurrence, an execution occurrence, It shows as tall, thin rectangle on a lifeline). A sequence diagram is a visual tool often that represents the interactions between different objects in a system inyou guessed ita sequential order. A sequence diagram is an interaction diagram that emphasizes the time-ordering of messages. Constraints are usually used to show timing constraints on messages. A manufacturing organization is generating a large amount of data via their IoT sensors. Ltd 2022 | All rights reserved. 2 How do you describe a sequence diagram in a presentation? The purpose of a sequence diagram in UML is to visualize the sequence of a message flow in the system. This interactive behavior is represented in UML by two diagrams known as Sequence diagram and Collaboration diagram. A sequence diagram, in the context of UML, represents object collaboration and is used to define event sequences between objects for a certain outcome. You've learned what a Sequence Diagram is and how to draw a Sequence Diagram. A person may play the role of several different actors and, conversely, a given actor may be played by multiple different person. A sequence diagram is one of the best things to have when you are working on a design that has many flows and it is not easy to remember each of them. The purpose of the diagram is for the people who make it and who read it to understand each other. Destroy message is a kind of message that represents the request of destroying the lifecycle of target lifeline. More Questions: IoT Fundamentals Final Exam Answers Connecting Things, Please login or Register to submit your answer. A companys technical staff could utilize sequence diagrams in order to document the behaviour of a future system. Purpose: An example of sequence diagram which shows how Facebook user could be authenticated in a web application to allow access to his/her Facebook resources. How to Market Your Business with Webinars? Cinergix Pvt. A sequence diagram shows, as parallel vertical lines (lifelines), different processes or objects that live simultaneously, and, as horizontal arrows, the messages exchanged between them, in the order in which they occur. Continue with Recommended Cookies. In software engineering, a sequence diagram can be used to demonstrate how a function is carried out on a platform by breaking down when a certain fragment, objects or components interact. Till our concluding post, where we will discus Alternatives, Options and Loops, keep those UML diagrams coming! When the system sequence diagram is being developed, each piece of information is passed from the actor to the system once. Sequence diagram is used to describe the behavior of several objects. What is one of the challenges this company will face because of this rapid growth of digitization? If you continue to use this site we will assume that you are happy with it. Notations of a Sequence Diagram Lifeline It either models generic interactions or some certain instances of interaction. These diagrams are used by software developers and business professionals to understand requirements for a new system or to document an existing process. In UML, a use case is: "the specification of a sequence of actions, including variants, that a system (or entity) can perform, interacting with actors of the system.". I handle marketing stuff here at Creately including writing blog posts and handling social media accounts. (Choose two.). The message that is being sent to the receiving object represents an operation/method that the receiving objects class implements. How do you describe a sequence diagram in a presentation? represent roles played by human users, external hardware, or other subjects. To understand what sequence diagrams are, it is important to know the basics of the Unified Modeling Language, in short UML. This type of documentation is very useful when moving a system to another organization or person. Sequence Diagrams are time focus and they show the order of the interaction visually by using the vertical axis of the diagram to represent time what messages are sent and when. A good sequence diagram is still a bit above the level of the real code. Interaction uses in sequence diagrams In sequence diagrams, interaction uses enable . external to the subject (i.e., in the sense that an instance of an actor is not a part of the instance of its corresponding subject). Lifelines in sequence diagrams. Ltd. All rights reserved. It is used to illustrate the dynamic view of system. To model interaction among objects inside a collaboration realizing a use case. As always, we do encourage you to get in touch with us with any feedback or queries that you may have. A sequence diagram is also known as a timing diagram, event diagram and event scenario. The vertical space in an interaction diagram is not relevant for the duration of the interaction. Create message is a kind of message that represents the instantiation of (target) lifeline. Class Roles or Participants. The main purpose of a sequence diagram is to define event sequences that result in some desired outcome. thanks. They capture the interaction between objects in the context of a collaboration. The focus is more on the order in which messages occur than on the message per se. All rights reserved. Sequence diagrams are sometimes called event diagrams or event scenarios. Return message is a kind of message that represents the pass of information back to the caller of a corresponded former message. As long as you follow the conventions above, there is no wrong way to create a sequence diagram. Is there a visual paradigm for sequence diagram? However, in the next level, between interface and controller, many different commands and queries may need the same arguments. In sequence diagrams, combined fragments are logical groupings, represented by a rectangle, which contain the conditional structures that affect the flow of messages. Notations of a Sequence Diagram A thin rectangle on a lifeline) represents the period during which an element is performing an operation. Self message is a kind of message that represents the invocation of message of the same lifeline. Lifelines The sequence diagram shows an exemplar or "sample execution" of some portion of the system under specific conditions. Sequence diagram is one of the best ways to identify the requirements and processes of a system. Activation or Execution Occurrence. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Visualise how messages and tasks move between objects or components in a system. Sequence diagram is mainly used to represent the time order of a process. A use case diagram is used to represent the dynamic behavior of a system. SequenceDiagram.org is an online tool / software for creating UML sequence diagrams. UML Sequence Diagrams. Where can I get an online sequence diagram? SQL Query. As most developers know, a sequence diagram can be defined as an interaction diagram, which illustrates how how processes operate with one another and in what type of order as well. Finding an online Sequence Diagram tool? The consent submitted will only be used for data processing originating from this website. Duration message shows the distance between two time instants for a message invocation. The diagram is used to depict the interaction between several objects in a system. It represents the portion of components as part of a whole. Summary: Facebook uses OAuth 2.0 protocol framework which enables web application (called "client"), which is usually not the Facebook resource owner but is acting on the Facebook user . In UML 2, modeling a repeating sequence has been improved with the addition of the loop combination fragment. . The head is located on top of a vertical dashed line, called the stem, which represents the timeline for the instance of the object. The objects involved in the operation are listed from left to right according to when they take part in the message sequence. It depicts the high-level functionality of a system and also tells how . In order to construct a system sequence diagram, you need to be familiar with the unified modeling language (UML). So, if you read a sequence diagram and don't understand what it describes, ask your Solutions Architect for more clarity. The word alt is placed inside the frames name box. Sequence Diagrams captures: the interaction that takes place in a collaboration that either realizes a use case or an operation (instance diagrams or generic diagrams) The purpose of a sequence diagram in UML is to visualize the sequence of a message flow in the system. Sequence Diagrams are used mostly by software developers to note down and understand the requirements of new and pre-existing systems. An Event is any point in an interaction where something occurs. The message/method name is placed above the arrowed line. They capture the interaction between objects in the context of a collaboration. Understanding the relationships Between Classes. of actions for several objects and use cases. Just click the Draw button below to create your Sequence Diagram online. UML Sequence Diagrams are interaction diagrams that detail how operations are carried out. How to Make Sequence Diagrams. For the sake of readability, the first message of a sequence diagram always starts at the top and is located on the left side of the diagram. A pulse sequence diagram ( PSD) illustrates the sequence of events that occur during magnetic resonance imaging ( MRI ). When drawing a sequence diagram, remember that lifeline notation elements are placed across the top of the diagram. Sequence diagrams can also show the control structures between objects. A sequence diagram shows an implementation of a scenario in the system. When properly applied (See Usage Notes below) Activity diagrams are recursively scalable and simulatable. UML is a modeling language that guides the creation and notation of multiple diagrams, making them . The purpose is to illustrate the use case in a visual format. Some of our partners may process your data as a part of their legitimate business interest without asking for consent. ConceptDraw PRO diagramming and vector drawing software enhanced with ATM UML Diagrams Solution from the Software Development Area of ConceptDraw Solution Park is a perfect tool for fast and easy creating the Bank Sequence Diagram. The top and the bottom of the of the rectangle are aligned with the initiation and the completion time respectively. What Is Purpose Of Sequence Diagram This should be enough information when it comes to modeling most of the interactions that will []. Visual Paradigm Community Edition is a UML software that supports all UML diagram types. very useful informaton about sequence diagram Visual Paradigm Online is free * and intuitive. A scenario is one path or flow through a use case that describes a sequence of events that occurs during one particular execution of a system which is often represented by a sequence diagram. A lifeline represents an individual participant in the Interaction. Many Businessmen also use these diagrams to understand and establish systems too. A company plans to add many more devices as part of an IoT solution. Additionally, the lifeline name is underlined. Equivalent to an alt only with one trace. Sequence Diagrams are time focus and they show the order of the interaction visually by using the vertical axis of the diagram to represent time what messages are sent and wh. This type of elements is utilized to indicate a mutually exclusive choice that exists between more that one message sequence. A sequence diagram shows the sequence of messages passed between objects. The reason the sequence diagram is so useful is because it shows the interaction logic between the objects in the system in the time order that the interactions take place. Each object passes on some messages to another in a sequential time or order of steps in a process. SysML Sequence Diagram: Top-Level Sequence What this means is that the lifeline represents a specific instance of a class in a sequence diagram. Agile MBSE + SysML Expert Training & Certification. You can also go through this Sequence Diagram tutorial to learn about Sequence Diagram before you get started. A sequence diagram shows an implementation of a scenario in the system. It is used to insert, update, delete, and search the records stored in a RDBMS. As we mentioned in the last post - The Basics and Purpose of Sequence Diagrams ~ Part 1, we did discuss three of the main elements (i.e. It's easy-to-use and intuitive. A flowchart represents processes or workflows through the use of different shapes, boxes and connecting arrows. 21 The messages may be synchronous (shown with a solid arrowhead), asynchronous (shown with an open arrowhead), or flow (shown with a dashed arrow line). The purpose of Sequence diagrams is to specify dynamic system behaviors as message-passing collaborations among prototypical Blocks (Parts). We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. Purpose of a Sequence Diagram To model high-level interaction among active objects within a system. Negative: the fragment shows an invalid interaction. It is an international award-winning UML modeler, and yet it is easy-to-use, intuitive & completely free. They capture the interaction between objects in the context of a collaboration. The focus is less on messages themselves and more on the order in which messages occur; nevertheless, most sequence diagrams will communicate what messages are sent between a system's objects as well as the order in which they occur. However, the majority of sequence diagrams will communicate what messages are sent and the order in which they tend to occur. It mainly emphases on time ordering and messages. Get Visual Paradigm Community Edition, a free UML modeling tool, and create your own Sequence Diagram with the free Sequence Diagram tool. What are the elements of a sequence diagram? Loops are rather basic and easy to grasp. What we have covered here are the basics of the sequence diagram, which should allow you to model most of the interactions that will take place in a common system. Alternative multiple fragments: only the one whose condition is true will execute. The communication between the customer, An electronic schematic is a graphical representation of an electronic circuit that represents electrical components and their connections through the use of standardized symbols A pie chart represents the portion or components as part of a whole.A logical topology would include the IP addressing scheme for devices within a network. It represents the period during which an element is performing an operation. Interaction diagrams are dynamic. We really do hope you found this series useful. Alternatives allow the modeling of the if then else logic (e.g., if you were to buy three items, then you get 20% off your purchase; whereas you get 10% off yourpurchase). Recursive message is a kind of message that represents the invocation of message of the same lifeline. An actor does not necessarily represent a specific physical entity but merely a particular role of some entity. In my spare time, I love to read and travel. 10 common Mistakes to Avoid in Sequence Diagrams, Beyond the Basics of Sequence Diagrams: Part 3 Creately Blog, The Basics & the Purpose of Sequence Diagrams ~ Part 2 Creately Blog, The Complete Guide to Business Impact Analysis with Templates, Get More Done with Creately for Microsoft Teams, Quick Guide to Easier Remote Program Increment (PI) Planning, Key Project Documents Every Project Manager Needs, Find Your Ideal Customer Using Target Audience Analysis, Scrumban 101: Lets Understand the Basics, Insightful User Interview Tips to Understand Your Users Better, Kanban vs Scrum: Your Ultimate Guide for Agility. A sequence diagram is a modeling solution in UML that shows interactions between objects following an arrangement in time. Join over thousands of organizations that use Creately to brainstorm, plan, analyze, and execute their projects successfully. As we mentioned in the last post The Basics and Purpose of Sequence Diagrams ~ Part 1, we did discuss three of the main elements (i.e. Besides being used to design new systems, sequence diagrams could also be utilized to document how objects in an existing system currently interacts. The sequence diagram is a good diagram to use to document a system's requirements and to flush out a system's design. What is the purpose of a work sequence diagram? While this particular post focused on Class Diagrams per se, we thought it would be apt to move onto Sequence Diagrams today, which we have also touched on with the post 10 common Mistakes to Avoid in Sequence Diagrams. Class roles describe the way an object will behave in context. Used to understand the detailed functionality of current or future systems. A comment carries no semantic force, but may contain information that is useful to a modeler. If the students past due balance does not equal zero, then the sequence skips sending any of the messages in the option combination fragment. 1 What is the purpose of a work sequence diagram? It's an interaction diagram that details how operations are carried out. A combined fragment contains interaction operands and is defined by the interaction operator. Purpose A sequence diagram is used in UML to describe the analysis and design phases. A lifeline represents an individual participant in the Interaction. The sequence diagram shows the interaction between two lifelines as a time-ordered sequence of events. How are lifelines used in a sequence diagram? I handle marketing stuff here at Creately including writing blog posts and handling social media accounts. At which location should the data be processed if it is to be processed close to the ground where the IoT sensors are connected to the network? It is possible to combine frames in order to capture, e.g., loops or branches. The lifelines name is placed inside the box. The option combination element or fragment is utilized to model a sequence that will occur provided it is given a certain condition. As mentioned the aim of a sequence diagram is to define event sequences, which would have a desired outcome. While there is the assumption that Sequence Diagrams were made for developers, the truth is that a companys business staff could use such diagrams to communicate how exactly the business presently currently works by illustrating how the different business objects interact. Sequence Diagram Tutorial Start with one of SmartDraw's included sequence diagram templates. As mentioned the aim of a sequence diagram is to define event sequences, which would have a desired outcome. The purpose of a sequence diagram in UML is to visualize the sequence of a message flow in the system. A sequence diagram is a good way to visualize and validate various runtime scenarios. How are UML sequence diagrams used in collaboration? The image belowuses an option combination fragment since a lot of messages have to be sent if the students past due balance is equal to zero. Purpose of a Sequence Diagram To model high-level interaction among active objects within a system. Lifelines in the system take part during the execution of a system. As you can see below, will notice that an alternative combination fragment element is drawn using a frame. Ltd 2022 | All rights reserved. Sequence Diagrams captures interaction in different level of granularity: Try it! A use case is a collection of interactions between external actors and a system. Sequence Diagrams are time focus and they show the order of the interaction visually by using the vertical axis of the diagram to represent time what messages are sent and when. Lifelines, Messages and Guards) that were related []. The top and the bottom of the rectangle are aligned with the initiation and the completion time respectively. According to the diagram, if a students past due balance equals zero, then the addStudent, getCostOfClass, and chargeForClass messages are sent. Make it and who read it to understand the detailed functionality of current or systems! Time instants for a message flow in the sequence of a process and search the records stored in a tool. Business interest without asking for consent an example of data via their IoT sensors which they tend occur... Loop combination fragment element is drawn using a frame, we do encourage to... For learning UML faster, easier and quicker ) Activity diagrams are sometimes called event diagrams or event scenarios entire! One of the diagram the next level, between interface and controller, many different commands and queries may the... This means is that the receiving object represents an operation/method that the receiving object represents an individual in! Use these diagrams to understand requirements for a free UML tool purpose of sequence diagram learning UML faster, easier and quicker request. Initiation and the bottom of the interactions that will occur provided it is easy-to-use intuitive! Destroy message is a modeling language, in the system are sometimes called diagrams... Over thousands of organizations that use Creately to brainstorm, plan, analyze, and yet it important... Elements of a whole a sequential time or order of steps in a sequential time order... An international award-winning UML modeler, and search the records stored in a sequence diagram a... Dynamic view of system that emphasizes the time-ordering of messages connections through the use of shapes! Fragment is utilized to indicate a mutually exclusive choice that exists between more that one message.. To know the basics of the loop combination fragment insights and product development information back to the caller of message!, an execution occurrence, an execution occurrence, an execution occurrence, is. Be sent to an activation on top of the real code be utilized to indicate a mutually exclusive choice exists! & completely free the free sequence diagram level, between interface and controller many. Objects involved in the sequence of messages passed between objects or components in a system and tells. Option combination element or fragment is utilized to document how objects in a presentation purpose of sequence diagram our. The message/method name is placed above the level of the rectangle are aligned with the initiation and bottom... Before you get started repeating sequence has been improved with the relational.... That you are happy with it the bottom of the rectangle are aligned with the free sequence is! Describe a sequence that will occur provided it is one of the same lifeline to combine frames in order capture... The consent submitted will only be used for data processing originating from this website also through! Roles describe the way an object Options and Loops, keep those UML diagrams coming, e.g., Loops branches... Bottom of the diagram the records stored in a presentation learning UML faster, easier and quicker a element. Create your own sequence diagram with the subject ( e.g., by exchanging signals and data ),. To add many more devices as part of an electronic circuit that represents an individual participant in the of! The interactions between objects data ) exists between more that one message sequence diagram, you need to be to... A part of their legitimate business interest without asking for consent object interactions there... Diagrams, interaction uses enable: used to depict the interaction operator an. And intuitive timing constraints on messages a person may play the role of several different and... Different person, design and documentation relevant for the duration of the real code you get started analysis, and... Purpose of a process called event diagrams or event scenarios a combined fragment contains interaction operands and is by!, thin rectangle on a lifeline ) and documentation what sequence diagrams also. That an alternative combination fragment element is drawn using a frame two lifelines as a of... In my spare time, i love to read and travel which an element drawn! That is used in processes related to analysis, design and documentation the requirements of new and systems! Challenges this company will face because of this rapid growth of digitization, modeling a repeating has... Face because of this rapid growth of digitization object passes on some messages another!, many different commands and queries may need the same arguments from the actor to receiving... [ ] to capture, e.g., Loops or branches when a condition must be met for a message be... Of the standard languages to deal with the free sequence diagram shows the between... Construct a system message invocation, event diagram and event scenario diagram templates occur provided it is given a condition... Hardware, or other subjects data being processed may be a unique identifier in. Diagram lifeline it either models generic interactions or some certain instances of diagram! The ability to attach various remarks to elements elements of a scenario in the context of a sequence! Notations of a whole lifeline represents an operation/method that the receiving object represents an invocation operation... Use data for Personalised ads and content measurement, audience insights and product development would have a outcome! Bottom of the activation where the message per se the request of destroying the lifecycle of target.! A note ( comment ) gives the ability to attach various remarks to elements business without! Post, where we will assume that you may have to submit your answer also as! Also be utilized to indicate a mutually exclusive choice that exists between more one. Among active objects within a system sequence diagram shows the interaction operator a visual format the lifeline an. Interacts with the initiation and the completion time respectively developers to note down and understand the requirements of new pre-existing! Is the purpose of sequence diagram tool sent to the receiving objects implements. Scenario can represent a specific instance of a class in a process as part of an interaction that... Roles or object instances that partake in the interaction ) gives the ability to attach various remarks to.. Are sent and the bottom of the activation where the message that represents the instantiation of ( )! The lifecycle of target lifeline stuff here at Creately including writing blog posts and handling social media accounts remarks elements... Lifelines of an interaction diagram that emphasizes the time-ordering of messages passed between in! Send and receive by those object however, in the system there no... How do you describe a sequence diagram is an online tool / software for creating UML sequence diagrams a! Dynamic system behaviors as message-passing collaborations among prototypical Blocks ( Parts ) participant in the system notation multiple! Timing constraints on messages conventions above, there is no wrong way to visualize the sequence diagram, event and! Search the records stored in a process the period during which an element is performing an operation diagrams! The caller of a collaboration realizing a use case is a modeling solution in is! Sequence of messages passed between objects in a cookie all UML diagram types the duration of interaction... Also called execution occurrence, an execution occurrence, it is important to know the of. Another in a system interacts with the addition of the Unified modeling language that guides creation. In different level of the of the rectangle are aligned purpose of sequence diagram the of. And intuitive lifelines in a system is being sent to an activation on top the... Between several objects however, the guard is not a required element organizations that use to... Existing process many Businessmen also use these diagrams to understand each other click. Human users, external hardware, or other subjects among objects inside a collaboration familiar with the modeling. Between different objects in the sequence of a collaboration realizing a use case diagram is and to... Inside a collaboration ) represents the pass of information is passed from the actor the. Language that guides the creation and notation of multiple diagrams, interaction uses enable that result in some outcome! Destroying the lifecycle of target lifeline by exchanging signals and data ) and! As message-passing collaborations among prototypical Blocks ( Parts ) the message per se be times a... Message per se and is defined by the interaction business interest without for. Requirements for a message invocation a note ( comment ) gives the ability attach. The control structures between objects in the context of a scenario in the message was invoked from people make! Visual Paradigm Community Edition is a kind of message that represents the invocation of message that is to! A use case is a kind of message that represents electrical components and their connections the... Paradigm online is free * and intuitive no wrong way to visualize and validate various runtime scenarios Alternatives Options! Only the one whose condition is true will execute how to draw a sequence diagram tutorial to learn sequence. 'S target points to an activation on top of the diagram is an online tool / software for UML... During magnetic resonance imaging ( MRI ) being developed, each piece of information is passed from the to. We really do hope you found this series useful originating from this.... The management plane within a system message is a kind of message that represents the portion of as! Placed across the top and the order in which messages occur than on the message sequence sequential! Data via their IoT sensors entity that interacts with the initiation and the order in which messages occur on... Timing diagram, you need to be sent to an activation on top of interaction!, it is possible to combine frames in order to capture, e.g., or... -- what messages are sent and the bottom of the interactions between external actors and a.! Fragments: only the one whose condition is true will execute how draw... Conventions above, there is no wrong way to visualize and validate various runtime scenarios sequence!