powerful simple modeling language


multi level hierarchy

5-level hierarchy

Represent your model in terms of systems, subsystems, modules, components and objects.

dynamic objects

dynamic objects

Objects may be eternal or they may be created and destroyed during feature execution.

share dynamic object instances

share instances

Dynamic objects may share instances. This is particularly useful in models with large number of entities.


message interactions

message interactions

Model asynchronous message interactions between source and destination objects.

message cascades

message cascades

Compactly represent a chain of message interactions involving multiple entities.

parameters and links for message details

parameters. links.

Specify a parameter list. Add hyperlinks to messages. Readers click on links in PDF to get message details.

more messages

message tagging

message tagging

Add tags to the source and destination to specify the protocol layer or port number in the message interaction.

lost message

lost message

Depict messages that are not received at the destination. This is useful in modeling error scenarios.



Model message multicasts and broadcasts.

objects. sequences.

model method calls

object interactions

Represent method calls and return values. All invocation and return statements permit specification of an optional parameter list as attribute-value pairs.



Group together several statements. Sequences may be nested.

collapsed sequence

collapse sequences

Reduce diagram size by automatically collapsing sequences in alternative scenarios. Clicking on the collapsed sequence shows complete contents.

actions. states. timers. resources.

actions and state transitions

actions. states.

Model actions and state transitions at object, component, module, subsystem or system level. Actions specification may be split into begin and end action.



Specify timer start, stop and expiry. Periodic timers are supported as well. EventStudio detects free running timers in design reviews.

allocate resources


Model resource allocation and deallocation. EventStudio will also catch resource leaks during a design review.

multiple scenarios

case statement with multiple legs

define multiple legs

Define multiple legs. EventStudio keeps track of multiple legs as scenario definitions.

if else statement


Define actions on previously selected legs with if-else statements.

scenario definition

define scenarios

Group interactions into logical scenarios. This also helps in multi-scenario sequence diagrams as multiple occurances of the scenario are collapsed into a reference to the original occurance.


include files

include files

Built in preprocessor lets you include FDL files. This permits sharing of design components across projects.

macro definitions

macro definitions

Define parameterized macros that let you define repeated sequences as macros.

conditional compilation

conditional compilation

Specify conditional compilation statements to keep track of the design of multiple releases in a single model.

formatting and styling

apply styles

statement styles

Control the color, fonts and line size with style specification. Default styles may be specified for each statement.

entity styles

Associate styles with entities to control axis formatting. You may also specify images that should be included with the headings.

regular expression styling

Style specification may be based on content. Associate a regular expression with a style and EventStudio will automatically apply the style.