In ESF, the user may have to manage all the functionnal datas of his system in addition of the dysfunctionnal datas related to the system analysis. It is important to define concepts used in order to understand the different features available. In a general manner, the functional concepts are used during the design step of the system, the dysfunctional concepts are used during the local analysis of each elementary component.
Local Analysis (LA) consists of the definition of the local effects of each elementary block of the system. It consists in linking the failures modes of the block stream output with the failure modes of its input stream (or with internal failures)
Two functional concepts are used by LA with the objective of linking the elements from the architecture of system.
This concept is a reference to a SBlock element from the architecture of system. An element applied by this concept stores the LA of its referenced SBlock.
This concept is a reference to a SPort element from the architecture of system.
ESF allows to configure dysfunctional mode impacting all the SBlockLAnalysis of the model. Those events can be - for example - electromagnetic interferences or an increase in the temperature,... Those events are then usable in the dysfunctional equation of each SBlockLAnalysis during the LA.
The system events are presented by two annotations:
In parallel of system failure, ESF allows to design internal failure into a SBlockLAnalysis. These local events cannot be reused for other SBlockLAnalysis.
A failure mode specifies how the related element ( Port or Barrier) fails. By default, three failure modes are available:
When a barrier is used in the LA of a SBlockLAnalysis, it correponds to an implicit barrier. Therefore, a barrier symbolises an inner system that allows to reduce the failure probability at the current SBlockLAnalysis's outputs (e.g., inner controls, defensive programming...).
In order to design the barrier failures, each one has his own failure modes.
Dysfunctional association aims to link SPortLAnalysis or barrier to failure mode. It defines the failure mode's owner.
Logic gates factor the failure propagation within a SBlockLAnalysis by combining propagation link with a boolean logic.
Propagation link aims to link several elements of the LA and indicates how a failure is propagated within a SBlockLAnalysis. Propagation link is oriented and allows only certain types of element as source and target.
The source of a propagation link can be:
The target of a propagation link can be:
Right click on the SBlock element (e.g., Standby) shown in "Model Explorer" and select "ESF Analysis Tools > ESF Local Analysis > Start new Local Analysis".
In the SSafetyArtifacts element, many elements are created:
Note: Before start a new Local Analysis, verify that all SPort elements of SBlock have defined their direction (see "Help > ESF Documentation > User Manual"). This information is automatically computed from the provision or requirement of packages and can be refined by Papyrus customizations such as Papyrus for Robotics. It can be manually overwritten, if required via the "Manual Direction" attribute in the "Properties View" tab.
This package store all System Event Types (SSysteEventType elements) of the whole system. There are threes ways to add a new SSysteEventType
First way, it is directly on a System Events Library Table. Right click and select "ESF Analysis Tools > ESF Local Analysis > Create a new System Event Type".
Second way, it is directly on a SystemEventsLibrary Table. Right click and select "ESF Analysis Tools > ESF FMEA > Create a new Failure Mode".
Third way, it is via ESF Local Analysis Diagram (see more below).
There is a synchronization between the model and the SystemEventsLibrary Tables. The result of actions of "add" and "remove" a System Event Type is reflected on both sides.
Note 1: The other System Events Library tables can be created: right click on the SSystemEventsLibrary and select "ESF Analysis Tools > ESF Local Analysis > Create a new System Events Library Table".
Note 2: If the SSystemEventsLibrary is deleted, a new can be created: right click on the SLocalAnalsyis and select "ESF Analysis Tools > ESF Local Analysis > Create a new System Events Library". The other way is starting a new Local Analysis. This library is unique for each project.
This package store all Feared Events (SFearedEvent elements) and Feared Events Families (SFearedEventsFamily elements)of the whole system. Via the context menu on Model Explorer a Feared Event or a Feared Events Family can be created.
Rule:
Note 1: If the SFearedEventsLibrary is deleted, a new can be created: right click on the SLocalAnalsyis and select "ESF Analysis Tools > ESF Local Analysis > Create a new Feared Events Library". The other way is starting a new Local Analysis. This library is unique for each project.
For doing a Local Anaslysis open an "ESFLocalAnalsysis Diagram" (ELAD) in a SBlockLAnalysis.
If there is not an ELAD created or if you want add other ones, right click on the SLocalAnalsyis and select "ESF Analysis Tools > ESF Local Analysis > Create an ESFLocalAnalsysis Diagram".
The ELAD offers a palette with the elements of ESF Local Analysis Concepts (see the topic Concepts).
Rule:
Note 1: When a System Event is added a dialog is opened for setting its type. By the dialog, there are two ways to define a type: the first, it is to create a new System Event Type (SSystemEventType) element; the second, it is to select a System Event Type element present in the System Events Library.
Note 2: For associating the Feared Events to a Failure Mode: select a failure mode (SFailureModeLAnalysis) element and go to the "Properties View", click on "ESFLocalAnalysis" tab. Many Feared Events and Feared Events Families could be adding to the respectives failure mode' attributes.
An example of Local Analysis done to StandBy.